Sterling Tools Limited (training report)

INDUSTRIAL TRAINING REPORT

STERLING TOOLS LIMITED

DLF-5A

FARIDABAD, HARYANA

SUBMITTED BY:

PRINCE NASWA

BTECH MECHANICAL STUDENT

(ITM UNIVERSITY, GURGAON)

ROLL N0. : 12-MEU-067

1

ACKNOWLEDGEMENT

An undertaking of work life - this is never an outcome of a single person; rather it bears

the imprints of a number of people who directly or indirectly helped me in completing the

present study. I would be failing in my duties if I don't say a word of thanks to all those

who made my training period educative and pleasurable one. I am thankful to

STERLING TOOLS LIMITED, FARIDABAD for giving me an opportunity to do

summer training in the company.

First of all, I am extremely grateful to Mr. GAGAN JAIN (PRODUCTION

MANAGER) AND Mr. GAURAV for their guidance, encouragement and tutelage

during the course of the internship despite their extremely busy schedule. My very special

thanks to them for giving me the opportunity to do this project and for his support

throughout as a mentor .I must also thank my faculty guides Mr. ASHWINI SHARMA,

Mr. MOHIT DESWAL AND Ms. SHIKHA (Faculty, ITM

UNIVERSITY,GURGAON) for their continuous support, mellow criticism and able

directional guidance during the project. I would also like to thank all the respondents for

giving their precious time and relevant information and experience, I required, without

which the Project would have been incomplete. Finally I would like to thank all lecturers,

friends and my family for their kind support and to all who have directly or indirectly

helped me in preparing this project report. And at last I am thankful to all divine light and

my parents, who kept my motivation and zest for knowledge always high through the

tides of time.

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ABSTRACT

This project dwells upon my project training at an esteemed NCR biggest Gasket

manufacturing organization, STERLING TOOLS LIMITED from 19.05.2014 to

1.07.2014. This training is a part of my course curriculum pursuing at ITM

UNIVERSITY, GURGAON.

In these 6 weeks I learnt the zest of the functioning of a manufacturing industry and how

the theoretical knowledge is applied in the working of the industry. I came to know about

the importance of safety of men, machine and equipment’s and the various steps that

need to be taken in this area to ensure their safety. I got an overview of each and every

department that works for making an industry a success, from R&D department to

packaging to dispatch department. I also learnt about the commitment of the company

towards quality of automobile products it produces and efforts made by all to ensure the

best quality of products.

It gives me immense pleasure to present this project report. The report commences with

company profile in which all the relevant details about sterling factory have been

included avoiding the secrecy norms of the company.

Learning in sterling was not limited to doing project only. I would like to say that my

experience in this factory would be unforgettable one throughout my life.

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TABLE OF CONTENTS

1. COMPANY PROFILE………………………………………………………………...6

2. INTRODUCTION.………………………………………………………..………......16

2.1 TECHNICAL ASPECT………………………..…………………………………..17

2.2 RAW MATERIAL………………………………………………………………..18

3. FORGING……………………………………………………………………………..20

3.1 WIRE STRAIGHTENING.….…………………………………………………….21

3.2 TYPE OF HEADS…………………………………………………………………22

3.3 HEAD FORMATION……………………………………………………………...27

3.4 DEFECTS………………………………………………………………………….29

3.5 SAFETY EQUIPMENTS………………………………………………………….29

4. THREAD ROLLING………………………………………………………………….30

4.1 PROCESS ………………..………………………………………………………..31

4.2 DEFECTS……………………………………………….………………………....32

5. MACHINING PROCESS……………………………………………………………..34

6. HEAT TREATMENT……………….………………………………………………...41

6.1 PROCESS CONTROL PLAN……………………………………………………..42

6.2 DEFECTS………………………………………………………………………….48

7. SURFACE FINISHING……………………..………………………………………..49

7.1 PROCESS FLOW………………………………………………………………….50

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7.2 PARAMETERS FOR QUALITY…………………………………………………55

7.3 CHEMICAL TEST’S…………………………………………………………...…56

7.4 DEFECTS………………………………………………………………………….57

8. LAB TEST’S……..…………………………………………………………………...58

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COMPANY PROFILE

HISTORY:

Sterling tools limited (STL), is a well-established, dynamic and professionally managed

company, is a leading manufacturer of fasteners in India. The company was incorporated

as a private limited company in 1979 and was turned into a public limited company in

1994. In 1979 the company was incorporated as a private limited company on 7th June

and at that time the Company undertook to expand its production range from 16mm

diameter fasteners to 24 mm diameter fasteners. The Capacity was also increased to 230

million pieces from the existing 165 million pieces. In terms of tonnage, installed

capacity was increased to 7000 tons from 3200 tons.

This process of expansion carried on and company spent a huge amount on expansion

and quality aspect in 2005. Now Sterling tools is the third largest fastener manufacturing

company in India.

Today, STL is among the leading OEM suppliers in India serving the needs of leading

automotive companies in India, Europe and USA. A large part of this success can be

credited to our competent workforce that has helped us surpass new boundaries at every

step. It is through their contribution that we have been able to achieve our corporate

vision of “sustainable growth through overall excellence”.

The '360 degree' philosophy looks at all aspects of the company, from manufacturing and

quality control to human resource development as a tool to produce total customer

satisfaction. All around excellence for all around perfection…this is the promise of '360

degree' approach.

MANUFACTURING:

With the expertise of over two decades, STL manufacturing facility today includes state-

of-the-art annealing, cold forging, inline rolling, heat treatment, finishing/coating, CNC

turning, centre less grinding, circular thread rolling and other secondary operations.

In addition, company have also introduced a complete range of multi station headers with

automatic motorised adjustment systems that facilitate smooth and fast job changes.

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Induction hardening of critical fasteners, use of sophisticated in-line hardening and

tempering furnaces with auto-load, pre-wash and post-washers, and the manufacture of

special fasteners with very close tolerance are key features of our manufacturing process.

STL finishing operations with hydrogen embrittlement facilities also include complete

waste treatment processes that bring us a step closer to an eco-friendly environment.

ENGINEERING:

STL's engineering department is led by a team of highly experienced leaders. Equipped

with the latest in CAD and simulation softwares and armed with the knowledge of an

extensive library, our engineering team is extremely competent, especially in the

manufacture of precision parts. Manufacturing feedback for improving the overall

machine effectiveness (O.E.E), APQP (Advanced Product Quality Planning) through

cross functional teams and in-house testing facilities like the SCHATZ torque testing

machine helps us understand and meet client needs consistently.

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SURFACE TREATMENT AND COATING:

To meet the demands of a dynamic market environment, we offer Cr6+ free multi-colour,

micro-layer corrosion protection systems in accordance with strict environmental

regulations. Leading brands like Geomat™, Delatone™/Deltaseal™ and Dacromat™ are

used as coating finishes for our range of fasteners, as per the needs of leading

automotive/Tier-I players worldwide.

TESTING:

In order to ensure consistent quality of the final product, company have harnessed the

power of several high accuracy specialised instruments. These include the Contour graph,

Metrology-fisher scope, Tri-roll guages for thread checking, Torque wrench, Vicker

hardness tester, Eddy current tester, Spectrometer, Microscope (with image analyser),

Universal tensile machine and the Charpy tester. By identifying potential problems and

flaws early, we ensure that STL fasteners reduce operating and replacement costs and

ensure greater operating safety.

QUALITY:

STL’s focus on quality is evident from our attention to cellular manufacturing, operator

quality assurance and established traceability. In addition, STL’s NABL certified

laboratories equipped with various high accuracy specialised instruments ensure

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unquestionable quality at every step. Little wonder then, that our manufacturing facilities

are all TS 16949 and ISO 14001 certified.

Quality Certifications:

ISO 14001:2004 Certification

ISO/TS-16949:2002 Certification

Testing Laboratory Certification by NABL

PRODUCTS:

Sterling tool manufacture a wide range of fasteners based on the following standards:

- Indian Standards-IS

- German Standards-DIN

- Japanese Standards-JIS

- American Standards-ASTM

- British Standards-BS

STL's product range encompasses a wide variety of standard, chassis, engine and special

fasteners.

Special Fasteners

Special fasteners are manufactured to suit unique customer specifications. Available in a

variety of surface protection coatings, these fasteners are proof of the fact that we provide

complete customizable solutions.

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Standard Fasteners

Known for their excellence, our range of standard fasteners include socket head cap

screws, hexagonal head bolts, studs, hexagon nuts and weld nuts. The dual benefits of

better fatigue resistance and superior strength have made these fasteners a popular choice.

Chassis Fasteners

Our range of chassis fasteners include hub/wheel bolts, hub nuts, wheel studs, suspension

bolts, propeller shaft bolts/nuts, centre bolts, track shoe bolts/nuts, rivets and two wheeler

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spindles/wheel axles. These are widely used in the undercarriage of automobiles and

heavy earth moving equipment’s.

Engine Fasteners

Engine fasteners include cylinder head bolts/screws, fly wheel nuts/bolts, connecting rod

bolts/nuts, balance weight bolts and main bearing cap bolts. These are widely used in

internal combustion engines.

Size Range:

Bolts and Screws

Size: M5 to M24 and equivalent inch series

Lengths: 8 mm to 250 mm

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COSTUMERS:

The favoured supplier to all major OEMs in India, we at STL have used our experience

and understanding to serve the needs of market better. By providing full traceability from

quote to delivery and providing access to the STL product range in remote corners of the

Indian subcontinent through our well established dealer network, we have brought

ourselves closer to our customers. That's why leading automobile companies in India and

abroad have continued to place their trust in our product range.

DOMESTIC: AFTERMARKET

STL’s aftermarket network comprises more than 60 dealers and the numbers are growing

rapidly with every passing day. With regional offices in both Chennai and Pune and

residential representatives in places like Jamshedpur and Mumbai we have been able to

interact closely with automobile dealers, fleet owners and mechanics.

This has helped STL gain a better understanding of their needs and enabled us to serve

them better. By further strengthening our foothold in this segment, we intend to make our

presence felt in every part of the country.

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Locations

Our Presence (India): Our Presence (Overseas)

Agra Bangladesh

Ahmedabad Detroit (USA)

Allahabad Nepal

Ambala Italy

Banglore

Chandigarh

Chennai

Cuttack

Ernakulam

Gandhinagar

Ghaziabad

Gorakhpur

Guwahati

Hyderabad

Indore

Jalandhar

Jammu

13

Jamshedpur

Kanpur

Kolkata

Lucknow

Ludhiana

Meerut

Mumbai

Nasik

Patna

Puna

Ranchi

Salem

Trivandrum

Varanasi

Vijaywada

Head Office: Faridabad

Registered Office: New Delhi

Plants:

1. Faridabad

2. Ballabhgarh

3. Prithla

4. Uttaranchal

Details of some of major customers and their contribution to revenue are as follows:

Maruti Udyog 14.97%

Tata Motors 14.90%

Mahindra & Mahindra 7.40%

Hero Honda Motors 10.38%

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Honda Motorcycle & Scooters 7.14%

Ashok Leyland 7.00%

Bajaj auto 5.03%

Escorts 6.11%

Eicher 6.71%

Investor Relations

Sterling Tools Limited, (BSE: 530759, NSE: STERTOOLS), is engaged in the

manufacturing of high-tensile (HT) cold forged fasteners mainly for automobiles. The

Company is one of top 3 fasteners manufacturers in India and caters to leading

automotive companies in India, Europe and USA. STL has 3 plants which are located in

Faridabad and has over 900 employees. The product portfolio includes special fasteners,

standard fasteners, surface treatment and coatings, chassis fasteners and engine fasteners.

The objective of Sterling Tools Investor Relations is to ensure continuous and open

communication with all financial market participants.

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INTRODUCTION

An industrial fastener comprises a very wide range of items like nuts and bolts, washers,

studs, nails etc. Nuts and bolts consist a major link in the family of industrial fasteners

and are used by every industry. Bolt is a piece of metal rod, whose one end is unsettled

and other end is threaded. Nut is the item, which rolls

on these threads. Nut and bolts are available in various shapes, designs and sizes.

Nuts and bolts are used for fastening purpose in industries where the replacement of

pieces and the parts is necessary. There are many industries producing these nuts and

bolts of various sizes, but the demand too is increasing as well as the raw material for the

product is easily and indigenously available. The main raw material is mild steel wire

coil/rod of required diameter. The composition of materials controls the quality of the

bolts and nuts.

The recommended composition for nuts and bolts raw material is given as under:

Carbon 0.22 to 0.23%

Phosphorus 0.40%

Manganese 0.39 to 0.60%

Sulphur 0.50%

Nuts and bolts are classified by two ways: i) Their uses, ii) Shape of head.

In terms of use, nuts and bolts are of several types:

Larger dia bolts, machine bolts, stand bolts, joint bolts, foundation bolts and nuts etc. in

terms of shape, bolt and nuts are classified by head shape like hexagonal head, square

head, round head, pan head, truss head etc.

MARKET POTENTIAL:

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The demand of nuts and bolts is influenced by the following factors:

Transportation industries, Railways, aircraft, wagon, bicycles, automobile, body builders, etc.

Electrical industries like manufacturing of transformer, electric motors, fans etc.

Building activities such as construction of bridges, fabrication of various steel structures etc.

Other heavy and light industries, steel and wooden furniture, machine tools, Agricultural machines and agricultural implements etc.

As various types of MS and HT nuts and bolts are used in above sectors, the market

demand is directly proportionate to the development of these industrial segments.

TECHNICAL ASPECTS

Process of Manufacture:

The raw material used for manufacture of bolt is M.S. Rounds. As some of the rounds

available are rusty and not perfectly round and straight, it is necessary to make them

round. The rounds are pickled in the acid tanks, washed and drawn in a drawing machine.

The cleaned rod is fed into the cold heading machine. In the machine, one end of the rod

is cut into the desired length with cutting stroke and simultaneously the head formation

takes at another end. For the HT bolts, forging is done on hot forging press. The pins are

then trimmed in the trimming machine.

In quality bolts, the lower side of the head is also faced. Threading is done in the thread

rolling machines.

General Process Flow Chart

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Mild steel rod

Bolt cutting

Head making

Head trimming

Thread rolling

Polishing

Store/dispatch

RAW MATERIAL

Quality of bolts depends on the composition of various elements in raw material.

According to the composition required there are total 17 grades of raw material available.

Grade is decided according to the costumer requirement.

Costumer gives the grade of raw material to be used or tells the composition of various

elements required in the product. For eg. Costumer gives the percentage of carbon,

boron , sulphur or other elements according to the requirement and then the most suitable

grade to the specified composition is used in manufacturing.

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CHEMICAL COMPOSITION OF RAW MATERIAL

MATERIAL C Mn Si S P Cr B

1008 Min. 0.3

Max. 0.1 0.5 0.05 0.04

1010 0.08 0.3

0.13 0.6 0.05 0.04

1018 0.15 0.6

0.2 0.9 0.05 0.04

10B21 0.18 0.6 0.0008

0.23 0.9 0.3 0.025 0.025 0.003

10B21M 0.18 0.8 0.0008

0.23 1.1 0.3 0.025 0.025 0.003

10B35 0.32 0.7 0.15 0.1 0.0008

0.38 1 0.35 0.025 0.025 0.003

15B25 0.23 0.9

0.28 1.2 0.3 0.025 0.025 0.003

15B41 0.36 1.35 0.15

0.44 1.65 0.3 0.025 0.025 0.003

15B37 0.36 0.35 0.15 0.9 0.0008

0.42 0.50 0.3 0.025 0.025 1.15 0.003

1541 0.36 1.35 0.15

0.44 1.65 0.3 0.025 0.025

4135 0.33 0.7 0.15

0.38 0.9 0.3 0.025 0.025 1.1

4140 0.38 0.75 0.15 0.8

0.43 1 0.3 0.025 0.025 1.1

4137 0.35 0.7 0.15 0.8

0.4 0.9 0.3 0.025 0.025 1.1

19MnB4M

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SCM 435

SCM 440

FORGING:

Forging is a process in which material is shaped by the application of localized

compressive forces exerted manually or with power hammers, presses or special forging

machines. The process may be carried out on materials in either hot or cold state.

Forging is an effective method of producing many useful shapes. Typical forged parts

include rivets, bolts, crane hooks, connecting rods, gears, turbine shafts, hand tools,

railroads, and a variety of structural components used to manufacture machinery.

The forged parts have good strength and toughness; they can be used reliably for highly

stressed and critical applications.

A variety of forging processes have been developed that can be used for either producing

a single piece or mass – produce hundreds of identical parts.

Hot forging is the plastic deformation of metal at a temperature and strain rate such that

recrystallization occurs simultaneously with deformation, thus avoiding strain hardening.

For this to occur, high work piece temperature (matching the metal's recrystallization

temperature) must be attained throughout the process. A form of hot forging is isothermal

forging, where materials and dies are heated to the same temperature.

Cold forging involves impression die forging or true closed die forging with lubricant

near room temperature. Carbon and standard alloy steel forgings are most commonly

cold-forged. Parts are generally symmetrical. The primary advantage is the material

savings achieved through precision shapes that require little finishing. Completely

contained impressions and extrusion-type metal flow yield draft less, close-tolerance

components. Production rates are very high with exceptional die life. While cold forging

usually improves mechanical properties, the improvement is not useful in many common

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forging applications and economic advantages remain the primary interest. Tool design

and manufacture are critical.

Now the process of forging is given below:

WIRE STRAIGHTENING:

PROCESS OF STRAIGHTENING:

1. Feed the wire in the rollers.

2. Apply pressure and push wire ahead.

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3. Check all the vertical rollers are aligned.

4. Check all the horizontal rollers are aligned.

5. After this check all the rollers are rolling properly or not.

After straightening the wire passes through the feed tube. The stopper stops wire at

particular length. A cutter is attached adjacent to stopper which cuts the wire in

desired length. Now, the wire is passed through a series of subsequent die to give it

desired shape.It passes through 4 set of die’s.

The above given is a forging machine and its inside parts are shown below called house.

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This figure shows a wire stand on which wire is loaded and then straightened for forging

into bolts.

A forging machine consists of three basic parts:

1. CAM

It is the most important component for punching the bolt. It gives pressure and

timing of punch.

2. Transverse slide

It consists of rm, retainer, spring, gear and finger.

3. House

The wire passes through house and it consists of all other components.

TYPES OF HEAD’S

Shape of head is also given by costumer according to the type of product to be

manufactured. Normally, hex head bolts are major requirements of costumers as they

provide a good grip and a strong head.

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There are 9 types of bolt heads. Given below:

1. Hex head screw

2. Hex head bolt

3. Flange bolt

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4. Collar hex bolt

5. Stud

6. D Stud

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7. T Stud

8. 12 point corner

9. Indent head

Bolt Size:

Eg: M12 X 1.75 X L HHS

Here,

M12 represents the diameter of bolt

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1.75 is the pitch of bolt

L is length

HHS is the type of head

HEAD FORMATION:

Bolt head formation is a 4 station process.

1. Cut off

2. Cone formation

3. Heading

4. Final trimming

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DEFECTS:

1. Burr on head piece.

2. Chip mark on monogram.

3. Chip mark on bearing face.

4. Short feed piece.

5. Burr under head piece.

SAFETY EQUIPMENTS:

1. Gloves

2. Helmet

3. Shoes

4. Mask

5. Glasses

6. Harness(if climbing)

7. Oxygen mask (for harmful gases)

8.

Bolt production rate varies from 60 to 100 bolts per minute for bolts having diameter 5 to

12 mm.

And for diameter 12 to 25mm production rate is 50 to 70 bolts per minute.

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THREAD ROLLING:

Thread rolling is a metal rolling process used extensively in manufacturing industry to

produce screws, bolts and other fasteners. A common thread rolling process, used in

industry to manufacture threaded parts, involves forming the threads into the metal of a

blank by a pressing and rolling action between two die. The die surface hold the shape

and the force of action forms the threads into the material.

Thread rolling has an extremely high productivity rate, significantly higher than

producing threaded parts by machining. Machining is the alternative method to industrial

manufacturing of threaded parts. Producing threads by this method has several other

benefits over machining.

Benefits of thread rolling over machining:

1. Forming will harden the metal through cold working.

2. Does not waste material by cutting.

3. Produces a favorable grain structure.

For thread rolling a forged bolt is kept between a stationary and a moving die is allowed

to roll in between them. So, the threads are formed on bolt. And the bolt is ready for

further processes.

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PROCESS:

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DEFECTS:

1. DENT

2. THREAD DAMAGE

3. INCLINED THREAD

4. THREAD DIE MARK

5. BODY ROLLED

6. CHIPS

7. MATCHING CUT

8. THREAD GAP

9. FLAT THREAD

10. WITHOUT ROLLING

11. SETTING PIECE

12. DIE MARK ON FLANGE

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Forging and thread rolling department is divided into two modules according to the size

of bolts.

In module 1 bolts of size 5mm to 12mm are forged and threaded. It consists of 11 forging

and 8 rolling machines. Whereas in module 2 bolts of size 12mm to 25mm are forged and

threaded. It consists of 7 forging, 6 rolling, 2 stud rolling and 1open die header machine.

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MACHINING PROCESS:

Machining is a metal removal process in which excess material is removed to obtain

desired shape, size. Machining is done by using CNC machines which are highly efficient

as they are more accurate, less time consuming. So, more productivity and are cost

effective also.

Different operations performed on CNC for bolt machining are listed below:

1. Grooving

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2. Parting

3. Turning

4. Facing

5. Boring

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6. Threading

7. Bore in nut

External operations : 1. Parting off, 2. Grooving, 3. Turning, 4. Profiling,

5. Undercutting, 6. Face-grooving, 7. Threading

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In parting operations, the objective is to separate, as efficiently and reliably as possible.

One part of the work piece from the other. A straight cut is made to a depth equalling the

work piece radius of a bar. In grooving operations, the principle is the same but with the

difference that the cut is shallower and not taken to the center.

Grooving operations are less sensitive in some respects because the grooves are usually

not as deep, instead shape, accuracy and surface finish are often demands that need more

attention.

The machining process can be compared to a facing operation in turning, where the tool

is fed radially into the center.

The difference being that in the parting operation, the tool is a thin blade making a

narrow groove. There is material on both sides of the tool and thus the material to be cut

through should be as little as possible and the width of the cutting edge should be small.

This makes considerable demands on the performance, chip forming and stability of the

parting tool.

As the tool moves to the center, and if the spindle speed is kept the same, the cutting

speed will gradually decrease until it reaches zero at the center. In CNC-lathes, the

spindle speed is increased as the tool moves towards the center. Any decrease in cutting

speed is disadvantageous for the tool and one that can make severe demands on the

cutting edge. As the edge approaches the center, pressure increases as the tool is fed in at

the decreasing cutting speed.

Cycle time varies for different product according to the operations performed.

Discontinuous chips are formed.

Tool life also varies with the type of product.

TOOLS USED ARE:

1. KVTL2525 Single point tool

2. SVJBL2525 M16 Single point tool

3. MTJNL 2525M16 Single point tool

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4. SVHBL2525M16 Single point tool

5. SCLCL 06

6. BORING BAR To balance run out

INSERTS:

1. TNMG 160402MS

0.2mm insert, 6 point used for small diameter.

2. TNMG 160404

0.4mm insert 6 point

3. CCMT 060204FG

0.4 insert, used for boring tool.

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4. VBMT160404MT

0.4 insert, 2point insert.

LUBRICANT:

Lubricant is essential part to run a machine to avoid friction between tool and work piece

which indeed increases tool life.

Cutting oil used in lubricant is Mobyl cut- 100.

Lubricant composition is 3 to 5% of cutting oil.

So, for 100lt CNC tank:

95lt. water + 5 lt. cutting oil.

DM water or RO water is used in lubricant.

Lubricant is changed after every 6 months. Concentration of lubricant is checked daily

using refractometer. Composition is also verified daily and accordingly oil or water is

added.

Lubricant tank is cleaned twice a week and all chips, trump oil is removed.

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Ph is also checked daily using ph paper. Required ph for oil and water mixed is 8 to9 and

for DM water is 6 to7.

Instruments used for error measurement in machining:

1. Height gauge

2. Pappi dial

3. Dial gauge

4. Block

5. Gear gauge

Total 7 CNC manufactured by ACE designer and 19 threading machines are installed in

machining department.

After machining the bolt is sent for heat treatment.

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HEAT TREATMENT

Heat Treatment is the controlled heating and cooling of metals to alter their physical and

mechanical properties without changing the product shape. Heat treatment is sometimes

done inadvertently due to manufacturing processes that either heat or cool the metal such

as welding or forming.

Heat Treatment is often associated with increasing the strength of material, but it can also

be used to alter certain manufacturability objectives such as improve machining, improve

formability, restore ductility after a cold working operation. Thus it is a very enabling

manufacturing process that can not only help other manufacturing process, but can also

improve product performance by increasing strength or other desirable characteristics.

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PROCESS CONROL PLAN:

Loading: Free from size mix-up.

Free from thread damage.

Pre Washing: Free from oil.

Free from mix up.

Hardening, Quenching: Free from scaling.

Process:

1. Hardening temperature.

2. Conveyor speed.

3. Carbon potential.

4. Methanol flow rate.

5. LPG flow rate.

6. Mix fan running.

7. Uniform loading.

8. No products mix up.

9. Burnt time.

10. Quench oil temperature.

Post washing: Free from oil.

Tempering: Travelling time.

Zone temperature.

Unloading: Free from mix up.

Free from thread damage.

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LOADER

OIL SKIMMER

(SPERATES OIL FROM MATERIAL)

WATER SUPPLY

(TO REMOVE LEFT OVER OIL)

HARDING CONVEYOR

(SPEED ACCORDING TO THE TIME SET)

QUENCH IN OIL

(TO PREVENT DECARB.)

CONVEYOR

OIL SKIMMER

TEMPERING FURNACE

(TO AVOID BRITTLENESS)

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DYEING TANK

(WATER+CUTTING OIL, TO COOL DOWN)

UNLOADING

Gas flow meter is used to set LPG and Methanol concentration. There are 3 fully

automatic furnaces, temperature and other parameters are controlled by using computer.

HARDENING TEMPERATURE TABLE:

RAW MATERIAL HARDENING

TEMPERATURE ±10°C

CARBON POTENTIAL

±0.05

10B21/ 15B21

1541/15B41/ 4140

880 0.23

EN8/ 1045/ SCM440/ 4135/

10B35

860 0.36

1541 / 15B41 Carburizing temperature

900°c oil temperature 50 to

85°

0.8

MATERIAL GRADE TEMPERING TEMP. ±10°C

10B21 20/22 HRC

27/29HRC

515

460

44

15B25 / 19MnB4 30/33 HRC

7T,R

8.8, S

450

515

15B25 20/22 HRC 570

1541/15B41 21/23 HRC

8.8, 24/30 HRC

34/36 HRC

39/41 HRC

615

570

470

425

10B35 8.8, S

10.9

39/42

530

445

420

En8D 28/32 HRC 565

1045 28/35 HRC 545

4140, SCM 440 7T,R

8.8, 24/30 HRC

29/31 HRC

34/36 HRC

42/44 HRC

45/52 HRC

645

615

585

535

380

350

S70C 40/48 HRC 400

SIZE SPEED/SOAKING MIN.

(HARDENING)

SPPED/SOAKING

MIN.(TEMPERING)

M5,M6 & ¼” 70 75

M8, M7 & 5/6” 70 75

M9, M10 & 3/8” 75 80

M11, M12, 7/16”, ½” 75 80

M14 80 85

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M16 & 5/8” 85 90

M18 85 90

M20, M22 , 7/8”, ¾” 90 95

M24& 1” 95 100

QUENCHED HARDNESS:

MATERIAL HARDNESS(HRC) AS QUENCHED

MINIMUM MAXIMUM

10B21/ 10B21M 38 HRC 44 HRC

15B25 40 HRC 46 HRC

15B41/1541 50 HRC 56 HRC

4140/ 4135 50 HRC 56 HRC

1045/EN8D 47 HRC 54 HRC

10B35 47 HRC 54 HRC

GRADE HARDNESS(HRC)

7T,R 20 TO28

8T/8.8 , S 22 TO 32

9T/9.8 , T 28 TO 34

10T/10.9, V 32 TO 39

11T, W 34 TO 39

12.9, X 38 TO 44

PROCEDURE OF WARMING UP:

1. Turn ON all cooling water switches and supply the cooling water.

2. Start up the main power and control panel power.

3. Set the temperature controller.

4. Start up the mixed fan.

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5. Start up the heater switch and start heating.

6. Start up the transmission motor and start conveyor.

TEMPERATURE MAINTAINING:

1. The procedure of the first time warming up after long term off.

200 °c = 18 HRC ® 400°C=6 HR

2. Turning off the furnace for short term (2-5 days) need not require maintaining

procedure.

SHUTTING DOWN THE FURNACE:

1. Switch off the front washing tank heater after complete of the washing operator.

2. Confirm all the material has come out of the hardening furnace.

3. Stop heating, decrease the temperature and off the heating power.

4. Switch off the rear washing tank heater after complete of washing operation.

5. Turn off mixed fan when temperature reduces below 200°C.

6. As the furnace temperature lowers to 100°C or less, stop the cooling water supply.

7. Shut down the main power.

LPG AND METHANOL COMPOSITION:

Ensure minimum 100KGs stock of methanol and LPG. This prevents the entrance of

oxygen and maintains appropriate carbon content.

10B21 / 15B25 : 1500cc/hr. methanol

0.3 LPG in mm³/hr.

1541/4140 and all other grades : 2000cc/hr. methanol

0.3 mm³/hr. LPG.

DEFECTS:

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1. High hardness after tempering.

2. Low hardness after tempering.

3. Low as quench hardness.

4. Tempered microstructure.

EVALUATION:

Check grain growth and decarb in material.

SURFACE FINISHING

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ELCTROPLATING PROCESS FLOW:

Electroplating is the application of a metal coating to a metallic or other conducting

surface by an electrochemical process. The article to be plated (the work) is made the

cathode (negative electrode) of an electrolysis cell through which a direct electric current

is passesd. The article is immersed in an aqueous solution (the bath) containing the

required metal in an oxidised form, either as an aquated cation or as a complex ion. The

anode is usually a bar of the metal being plated. During electrolysis metal is deposited on

to the work and metal from the bar dissolves:

at cathode Mz+(aq) + ze-→ M(s)

at anode M(s) → Mz+(aq) + ze-

Faraday's laws of electrolysis govern the amount of metal deposited.

Articles are electroplated to

(i) Alter their appearance

(ii) To provide a protective coating

(iii) To give the article special surface properties

(iv) To give the article engineering or mechanical properties.

Most electroplating coatings fall into one of the following six categories:

1. Sacrificial coatings, used primarily for protection of the basis metal, usually iron and

steel (sometimes call anodic coatings, meaning that electrochemically they are anodic to

the substrate). Sacrificial denotes that the coatings "sacrifice" themselves in the act of

protecting the basis metal.

2. Decorative protective coatings, used primarily for adding attractive appearance to

some protective qualities.

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3 Engineering coatings - a rather miscellaneous group whose members are used for

specific properties imparted to the surface, such as solderability, wear resistance,

reflectivity, conductivity, and many others. They are sometimes called functional

coatings, though it would seem that protection is also a "function".

4. Minor metals - a small group of metals that are easily plated but have rather limited

application.

5. "Unusual" metals - rarely electroplated, and when they are, they require special

conditions, such as non-aqueous solutions.

6 Alloys - an almost unlimited number of alloys has been plated experimentally, since the

possible combinations of the plateable metals, in various proportions, are in numerable.

Only a few have attained commercial importance.

PROCESS FLOW:

PRE- TREATMENT

LOADING

SOAK DEGREASING

(TO REMOVE OIL, GREASE)

ANODIC CLEANING 1

(CLEANING USING CURRENT)

CASCADE RINSE

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(TO REMOVE CHEMICAL)

PICKILING

(REMOVE OXIDES)

CASCADE RINSE

ANODIC CLEANING 2

(TO REMOVE HARD SCALE)

CASCADE RINSE

ALKALI DIP

(TO MAKE SURFACE ALKALINE BASE)

PLATING

ALKALINE ZINC

CASCADE RINSE

UNLOAD TO BASKET

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POST PLATING/ PASSIVATION LINE

PICK BASKET USING TRANSPORTER

BRIGHT DIP

(FOR SHINE)

RINSE

PASSIVATION

(TRIVALENT BLUE/ YELLOW OR HEXAVALENT YELLOW)

CASCADE RINSE

FINAL RINSE

DEHYDRATION

HOT AIR DRYER

(TO REMOVE WATER & CHEMICALS)

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FINAL UNLOAD

DETAILED PARAMETERS

1. Loading

2. Hot degreasing 1

(Super soak - 50±5 G/lt.)

Temperature- 60 ± 5°C

Density- 6 ± 3 Be

Time- 8 ± 2 min

3. Electro degreasing 1

(Sterioclean-s-55 - 50 ± 5 g/lt. )

Temperature- 60 ± 5 °C

Density – 6 ± 3 Be

Time – 4 ± 2 min

C.D – 0.3-0.6 amp. /DM²

4. Acid pickling

(Commercial HCl – 200 ± 25 g/lt.)

Temperature – 35 ± 15 °C

Density – 18 ± 7 Be

Time – 7 ± 2 min

5. Electro degreasing

(sterioclean s-55 – 60 ±5 g/lt.)

Temperature – 60 ± 5 °C

Time – 4 ± 2 min

Density – 6 ± 3°Be

C.D – 0.3 to 0.6 amp./ DM²

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6. Alkaline zinc plating

(caustic soda – 130 ± 10 g/lt.)

(zinc metal – 10 ± 2 g/lt.)

Temperature – 25 ± 5 °C

Density – 20 ± 2 ° Be

Time – 80 ± 25 min

C.D – 0.4-0.9 amp./dm²

Voltage - 8±4 volt

7. Drag out tank.

8. Triple rinse tank

9. Unload.

PASSIVATION LINE:

1. Bright dip:

(Nitric acid – 20 ± 5 pointage)

Time – 11 ± 2 sec

Dosing – 22 ± 8 ml/lot

2. Trivalent silver white:

(Tridurmax BL-Cr³⁺ 3.0±0.5 g/lt)

Temperature – 42 ± 2°C

Ph – 2.8 ± 0.2

Time – 45 ± 15 sec

Dosing – 160 ± 20 ml/lot

3. Trivalent yellow:

(Tridurmax - Cr³⁺ 2.8 ± 0.3 g/lt)

(Yellow additive – 0.1 ml/lt)

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Temperature – 40 ± 2 °C

Ph – 1.6 ± 0.2

Time – 45 ± 15 sec

Dosing – 150 ± 20 ml/lot

4. Centrifugal dryer:

Temperature – 75 ± 25 ° C

Time – 6 ± 2 min

PARAMETER FOR QUALITY:

PROCESS PARAMETER

Hot degreasing 1. Temperature

2. Density

Electro degreasing 1. Temperature

2. Density

Alkaline zinc 1. Temperature

2. Zinc metal

3. Current

Passivation 1. Temperature

2. Ph

3. Cr³⁺

Top coat 1. Ph

Drying 1. Temperature

CHEMICAL TESTS:

a) Trivalent and hexavalent passivation confirmation.

b) Analysis of stiroclean s 55 in stiroclean s55 bath solution.

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c) Analysis of HCl (36%) concentration.

d) Analysis of super soak concentration in super soak bath solution.

e) Analysis of nitric acid (69%) concentration.

f) Analysis of Zn, NaOH and Na₂CO₃.

SST PARAMETERS (SALT SRAY TREATMENT):

Chamber temperature: 33.3-36.1 °C

Fog collection: 1-2 ml/Hr.

Air pressure: 10-25 psi

Solution Ph: 6.5-7.2

Solution specific gravity: 1.0255-1.04

DEFECTS:

1. Colour variation.

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2. Plating peels off.

3. Dull in thread.

4. Thread melting.

5. Excess/ low plating thickness.

6. Pitting.

7. No plating.

8. White rust formation.

9. Red rust observation.

10. Overall dull

After electroplating the samples are taken from each lot for lab tests.

LAB TESTS:

Samples are taken after each department for lab tests.

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Lab test instruments:

Rockwell hardness tester (digital)

For hard material C scale is used. Load 150kgf. Unit HRC.

For soft material B scale is used. Load 100kgF. Unit HRB.

For even soft materials A scale is used. Load 60 kgf. Unit HRA.

Optical emission spectrometer:

To check chemical composition of raw material.

Fischer scope:

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It is a measuring instrument for manual or automated coating thickness

measurements on functional coatings, corrosion protection coatings and mass-

produced parts.

 Typical fields of application

Measurements of mass-produced electroplated parts

Corrosion protection and decorative coatings such as chrome on nickel/copper

Bath analysis in the electroplating industry

Gold, jewellery and watch industries 

It is used to check plating thickness.

Error ±5%

Micro Vickers hardness tester:

Unit H.V. This is used for more accuracy. Can be used for weight material even

200gm.

Stereo microscope:

59

The stereo or stereoscopic or dissecting microscope is an optical microscope

variant designed for low magnification observation of a sample, typically using

light reflected from the surface of an object rather than transmitted through it.

The stereo microscope is often used to study the surfaces of solid specimens i.e. to

check surface discontinuity of product.

Carl zeiss microscope:

Microstructure decarbonization thread lock.

Brinnel hardness tester:

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For checking more area, more load.

Load 300 kg.

Torque wrench bench:

For torque testing.

After lab tests are passed the product is sent for packaging and then dispatch.

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CONCLUSION

It was really a wonderful experience to work as an intern in STERLING TOOLS

LIMITED, FARIDABAD. I gained a lot of insight regarding almost every aspect of the

industry. I was given exposure in almost all the departments at the industry. The friendly

welcome from all the employees is appreciating, sharing their experience and giving their

peace of wisdom which they gained in long journey of work. I came to know about how

the theoretical knowledge is to be converted into practical knowledge at various stages of

production of a particular product, in my case it was the production of bolts.

I learnt about the different processes used in making a bolt, from designing of a bolt to

the inspection of quality of bolt. I observed different machines and suggested ways on

how to improve it to accelerate the production. I also learnt about the technical

specifications of the different machines. Also, I learnt about the usage and importance of

various calibrating instruments at the CALIBRATION DEPTT.

My work in forging shop was really a fantastic one. Here apart from gaining technical

knowledge I came to know about various problems faced by the workers in the working

area. I even gave them suggestions on how to remove such a problem. Hope it will

contribute towards easing the life of a worker in the working area.

All in all this experience gave me the zest of how a manufacturing industry works. I hope

this experience will surely help me in the future and also in shaping my career.

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BIBLIOGRAPHY

1. STERLING WEBSITE (www.stlfastenerscom)

2. WIKIPEDIA

3. WWW.TOOLINGU.COM

4. MAGAZINES (AUTOMOTIVE PARTS)

5. GOOGLE IMAGES

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