WSTP-2-WK 1-4 PDF - Learning Module

0 TECHNOLOGICAL UNIVERSITY OF THE PHILIPPINES VISAYAS Capt. Sabi St., City of Talisay, Negros Occidental College of _________________________ Office of the Program Coordinator LEARNING MODULE WSTP 2: BENCH WORK DEPARTMENT: Manufac...

0 TECHNOLOGICAL UNIVERSITY OF THE PHILIPPINES VISAYAS Capt. Sabi St., City of Talisay, Negros Occidental College of _________________________ Office of the Program Coordinator LEARNING MODULE WSTP 2: BENCH WORK DEPARTMENT: Manufacturing Engineering Technology COMPILED BY:. ______________________________________ 2020 This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  1 VISION The Technological University of the Philippines shall be the premier state university with recognized excellence in engineering and technology at par with leading universities in the ASEAN region. MISSION The University shall provide higher and advanced vocational, technical, industrial, technological and professional education and training in industries and technology, and in practical arts leading to certificates, diplomas and degrees. It shall provide progressive leadership in applied research, developmental studies in technical, industrial, and technological fields and production using indigenous materials; effect technology transfer in the countryside; and assist in the development of small-and- medium scale industries in identified growth center. (Reference: P.D. No. 1518, Section 2) QUALITY POLICY The Technological University of the Philippines shall commit to provide quality higher and advanced technological education; conduct relevant research and extension projects; continually improve its value to customers through enhancement of personnel competence and effective quality management system compliant to statutory and regulatory requirements; and adhere to its core values. CORE VALUES T - Transparent and participatory governance U - Unity in the pursuit of TUP mission, goals, and objectives P - Professionalism in the discharge of quality service I - Integrity and commitment to maintain the good name of the University A - Accountability for individual and organizational quality performance N - Nationalism through tangible contribution to the rapid economic growth of the country S - Shared responsibility, hard work, and resourcefulness in compliance to the mandates of the university This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  2 TABLE OF CONTENTS Page Numbers TUP Vision, Mission, Quality Policy, and Core Values………………………1 Table of Contents………………………………………………………………..2 Course Description……………………………………………………….3 Learning Outcomes………………………………………………………… General Guidelines/Class Rules…………………………………………… Grading System…………………………………………………………… Learning Guide (Week No. 1) ……………………………………………. Topic/s……………………………………………………………… Expected Competencies………………………………………………… Content/Technical Information……………………………………… Progress Check…… ……………………………………………….. References………………………………………………………… Learning Guide (Week No. 2) …………………………………………… Topic/s……………………………………………………………… Expected Competencies………………………………………………… Content/Technical Information …………………………………… Progress Check…… ……………………………………………….. References………………………………………………………… Learning Guide (Week No. 3)……………………………………………… Topic/s……………………………………………………………… Expected Competencies…………………………………………………… Content/Technical Information…………………………………… Progress Check…… ……………………………………………….. References………………………………………………………… Learning Guide (Week No. 4) …………………………………………… Topic/s……………………………………………………………… Expected Competencies……………………………………………… Content/Technical Information…………………………………… Progress Check…… ……………………………………………….. References………………………………………………………… List of References……………………………………………… About the Author/s…………………………………………………………….. This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  3 COURSE DESCRIPTION This subject deals with the study of the theories and principles of different bench work and operations. It covers topics such as lay-outing, metal sawing, filing, hand threading and drilling. COURSE OUTCOMES GENERAL GUIDELINES/CLASS RULES GRADING SYSTEM This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  4 LEARNING GUIDE Week No.: __1__ TOPIC/S Bench Work safety, PPE, Fire Extinguisher EXPECTED COMPETENCIES Upon completing this Learning Module, the student will be able to: A. Understand the importance of safety and accident prevention in workshop B. Explain the basic principles of personal safety, including protective eye wear, clothing, gloves, shoes and hearing protection C. Identify the different classifications of fires and the proper procedures for extinguishing each. CONTENT/TECHNICAL INFORMATION A. SAFETY IN BENCH WORK Safety and Rules and Unsafe Practices Remember that “accidents do not occur, they are caused”. With this in mind, strictly follow the general safety rules given below and safe practices indicated in brief under each section. SAFETY PRACTICES AND MAINTENANCE 1. Keep the shop clean.\ a. Metal scraps should not be scattered on the floor. b. No horse playing c. No day dreaming this will increase your chance of injury. d. Compressed air should never be used to remove chips and cutting oil machine. - Flying chips may cause serious eye injuries - Vaporized oil may ignite and cause painful burns and properly damage. e. Oil rugs must be placed in a closed container and never be used again to avoid cuts and possible self- ignition caused by chemical action. f. Use care when handling long pieces of metal stock g. Keep hand tools in good condition and store them in a such a way that a person will not be injured when he secures a tool from the storage rack or tool panel. h. Get help when moving heavy machines, accessories or large pieces of metal stock. This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  5 i. Dress properly - Do not wear loose fitting sweater or clothing. - Rings and other pieces of jewelry that might be caught in moving parts should be removed. - Keep your sleeves rolled up. j. Have adequate ventilation for jobs where dust and fumes are a hazard. k. Always protect your eyes when there is a danger of flying chips. l. Know your job. It is foolish to operate machines without first receiving proper instruction. Get additional help if you are not sure what must be done or how it should be done. m. Keep your hands from all moving parts. You must resist the temptation to „‟FEEL” the machine surface of the work while the machine is running. Fingers have been lost this way. n. Take care of cuts and bruises no matter how small. Report every accident to your instructor. Make sure that cuts and bruises are properly attended.  OBSERVE SAFETY AT ALL TIMES  ALWAYS BE CAREFUL  FOLLOW INSTRUCTIONS  READ SAFETY PRECAUTIONS  NEVER OPERATE A MACHINE WITHOUT ASKING PERMISSIONS. o. Before operating, secure a clean and unified working area to avoid accidents and others. p. Be aware of the possible defects on machines which will be operated. Always check first before operating.\ q. After working, always clean your surroundings. B. What is PPE? PPE can include items such as safety helmets, gloves, eye protection, hazmat suits, high-visibility clothing, safety footwear, safety harnesses, ear plugs, ear defenders and respiratory protective equipment (RPE). In appropriate situations disposable PPE may be provided; eg single-use coveralls. Employers have duties concerning the provision and use of personal protective equipment at work. Why is PPE important? In the hierarchy of risk control, PPE is considered to rank lowest and represent the option of last resort. It is only appropriate where the hazard in question cannot be totally removed or controlled in such a way that harm is unlikely (for example by isolating the hazard or reducing the risk at source to an acceptable level). This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  6 There are a number of reasons for this approach:  PPE protects only the person using it, whereas measures controlling the risk at source can protect everyone at the workplace;  Theoretical maximum levels of protection are seldom achieved using PPE, and the real level of protection is difficult to assess (due to factors such as poor fit, or failure to wear it when required). Effective protection can only be achieved by equipment which is correctly fitted, maintained and properly used at all times;  PPE may restrict the wearer by limiting mobility, visibility or by requiring additional weight to be carried.  Use of PPE may alter employees‟ perception of the hazards they are dealing with. In this context of a last resort control measure, PPE is critically important as it is generally only used where other measures are insufficient and as such it plays a crucial role in preventing and reducing many occupational fatalities, injuries and diseases. c. Properly using a fire extinguisher in the workplace According to OSHA, the most common emergency small businesses must plan for is a fire. Fire extinguishers can be invaluable tools to help fight smaller fires in the workplace or to protect evacuation routes in the event of a larger one. OSHA requires employers to thoroughly train workers not only how to use an extinguisher properly, but also how to accurately assess a situation and determine when evacuation is the safest course of action. OSHA requires employees to be trained in fire extinguisher use on an annual basis, at a minimum. A simple fire extinguisher training technique to use with employees is the PASS method:  Pull the pin on the extinguisher.  Aim the hose nozzle low toward the base of the fire.  Squeeze the handle to release the extinguishing agent.  Sweep the nozzle from side to side at the base of the flames until extinguished. Knowing how to operate the extinguisher is not the end of training. Employee responders to a fire also should be trained to adhere to the following protocol:  If appropriate, sound the fire alarm or call the fire department immediately.  Before approaching the fire, determine an evacuation route safe of flames, excessive heat and smoke. Do not allow this evacuation route to become blocked.  Use the PASS technique for discharging an extinguisher and back away from the area if the fire flares up again.  If the extinguisher is empty and the fire is not out, evacuate immediately. This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  7  If the fire grows beyond what can be safely handled, evacuate immediately.  ire extinguishers are meant to handle only small fires. If a fire becomes too large or the environment becomes too dangerous, employees should know when and how to evacuate the area. If any of the following conditions are present, workers should follow evacuation procedures immediately and should not attempt to fight the fire with an extinguisher:  The fire is too large. The fire involves flammable solvents, is partially hidden behind a wall or ceiling, cannot be reached from a standing position, or covers more than 60 square feet in area.  The air is unsafe to breathe. Levels of smoke make the fire impossible to fight without some form of respiratory protection.  The environment is too hot or smoky. Radiated heat is easily felt, making it hard to approach a fire within adequate range of using the extinguisher (about 10-15 feet). It is necessary to crawl on the floor to avoid heat or smoke. Visibility is poor.  Evacuation paths are impaired. The fire is not contained and heat, smoke or flames block potential evacuation routes. According to OSHA, the most common emergency small businesses must plan for is a fire. Fire extinguishers can be invaluable tools to help fight smaller fires in the workplace or to protect evacuation routes in the event of a larger one. OSHA requires employers to thoroughly train workers not only how to use an extinguisher properly, but also how to accurately assess a situation and determine when evacuation is the safest course of action. OSHA requires employees to be trained in fire extinguisher use on an annual basis, at a minimum. A simple fire extinguisher training technique to use with employees is the PASS method:  Pull the pin on the extinguisher.  Aim the hose nozzle low toward the base of the fire.  Squeeze the handle to release the extinguishing agent.  Sweep the nozzle from side to side at the base of the flames until extinguished. Knowing how to operate the extinguisher is not the end of training. Employee responders to a fire also should be trained to adhere to the following protocol:  If appropriate, sound the fire alarm or call the fire department immediately. Types of Fires Not all fires are the same. Per NFPA 10, burning may be classified into one or more of the following fire classes and your fire protection specialist will select the right fire extinguisher size and agent for the hazard. This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  8 Class A Class A fires are fires in ordinary combustibles such as wood, paper, rubber, and many plastics. Class B Class B fires are fires in flammable liquids such as gasoline, petroleum greases, tars, oils, oil-based paints, solvents, alcohols. Class B fires al include flammable gases such as propane and butane. Class B fires do not include fires involving cooking oils and grease. Class C Class C fires are fires involving energized electical equipment such as computers,servers, motors, transformers, and appliances. Remove the power and the Class C fire becomes one of the other classes of fire. Class D Class D fires are fires in combustible metals such as magnesium, titanium, zirconium, sodium, lithium, and potassium. Class K Class K fires are fires in cooking oils and greases such as animal and vegetable fats. Some types of fire extinguishing agents can be used on more than one class of fire. Others have warnings where it would be dangerous for the operator to use on a particular fire extinguishing agent. This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  9 PROGRESS CHECK Multiple Choice  If you have long hair, how would you prepare yourself for working in the shop? a. Get a haircut b. Wash and dry your hair c. Use mousse or styling gel on your hair d. Tie your hair back or wear it under a cap 2. Loud noises in the mechanics lab causes others to be a. Happy b. Sad c. Prone to accident d. Talkative 3. Any small piece of metal should be ________ while drilling a. Clamp b. clean c. Oiled 4. Safety glasses are worn in the shop a. For grinding only b. At all times c. For drilling only d. When user feels it is necessary 5. Defective machines and tools may be used a. Temporarily to finish a job b. Only if defect is minor c. Never d. None of the above 6. Why is it important to remove jewelry and roll up sleeves when working in the shop? a. It‟s a cool look for the shop b. These items can get caught in equipment c. Jewelry can be distracting d. These items can collect dirt and dust 7. Shop clothing is unsafe if it is a. Loose b. Baggy c. Flammable d. All of the above 8. PPE stands for a. Proper protection equipment b. Protect public equipment c. Personal Protection equipment This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  10 9. MSDS a. Medical safety data services b. Material service data sheets c. Material safety data sheets 10. You should report which injuries? a. serious injuries b. only injuries to yourself c. injuries to other people d. All injuries to you other people REFERENCES Occupational Safety and Health Administration (2020). Evacuation Plans and Procedures eTool: Emergency Standards to Portable Fire Extinguishers. https://www.osha.gov/SLTC/etools/evacuation/portable.html Dixon,R. (1981). BenchWork: Delmar This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  11 LEARNING GUIDE Week No.: __2__ TOPIC/S Introduction to Bench work EXPECTED COMPETENCIES Upon completing this Learning Module, the student will be able to: 1. To explain and define BENCHWORK and identify its importance. 2. To identify the different HAND TOOLS and ELECTRIC HAND TOOLS. 3. To be able to know the different LINEAR MEASUREMENTS. CONTENT/TECHNICAL INFORMATION BENCHWORK is concerned with the ability to use all types of hand tools and operation of power driven machines like electric drills, electric grinders and etc. BENCHWORK is important in all fields of technology because basically, a technician must be able to use any type of hand tools as well as understand the theory and principles involved. Bench work is a term used to describe any type of labor or work that is managed using a workbench rather than with the use of heavy machinery in a plant setting or in a larger area. The term is also sometimes used to refer to the structures that support finished projects such as model train sets that are set up on a more or less permanent basis. With all applications, the idea is that the labor is completed at a stationary setting rather than relying on machinery to do the job. In terms of the creation of goods, there are several different examples of bench work. Carpentry bench work involves the crafting of different types of furniture or frames for upholstered furniture pieces. Here, the idea behind the bench work furniture creation is to carefully craft each component by hand, with some pieces built and assembled entirely on the workbench. At other times, the individual pieces are hand crafted as part of the bench work and assembled at another site. A. BENCH WORK HAND TOOLS AND ELECTRIC HAND TOOLS The following are the different types of hand tools and their respective operations.  HAND TOOLS 1. MEASURING- Steel rule, Combination squares, Vernier Caliper, Bevel, Vernier Protractor 2. LAY-OUTING- Scriber, Straight edge, Prick Punch, Center Punch, Divider, Lay-out dye 3. CHISELING- Cold chisel, Ball peen hammer, Machinist vise 4. SAWING- Machinist vise, Hand Hacksaw 5. DRILLING- Twist drill, Drill press, Electric Hand drill 6. FILING- Files, Machinist vise This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  12 7. REAMING- Hand Reamer, Pipe Reamer 8. THREADING- Threading die, Die holder, hand tap, Tap wrench 9. OFF HAND GRINDING-Pedestal Grinder 10. FORGING- Sledge hammer, Tongs, Anvil, Gas forge 11. COLD BENDING- Hand bender, Bending machine, Ball peen hammer 12. FITTING- Wrenches, Screw drivers, Welding Machine  ELECTRIC HAND TOOLS 1. Power Tool Combo Kits 2. Drills 3. Power Saws 4. Air Tools & Compressors 5. Rotary & Oscillating Tools 6. Shop Vacuums 7. Tool Storage & Work Benches 8. Welding & Cutting 9. Routers 10. Pneumatic Nailers B. LINEAR MEASUREMENTS 1. Steel rule 2. Vernier caliper 3. Micrometer 4. Bevel protractor 5. Try square , etc PROGRESS CHECK True or False 1. In Lay-outing a straight line one could use a steel tape. 2. Proper use of fire extinguisher is to aim at the fire 6meters away. 3. In Chiseling activity one should have ball peen hammer, cold chisel and a pair of cotton gloves only. This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  13 4. Oil rugs must be placed in a closed container and never be used again to avoid cuts and possible self- ignition caused by chemical action. Identify the hand tool and its Operation (Application) used for. Example: ballpeen hammer - chiseling 5. 6. 7. 8. 9. 10 11. 12. 13. REFERENCES Dixon,R. (1981). BenchWork: Delmar Laknepally, V., Narsampet, M. (2020). Engineering Workshop Laboratory Manual Department Of Mechanical Engineering. Retrieved From: Engineering-Workshop-i-Lab- Manual_1st%20year.pdf Occupational Safety and Health Administration (2020). Evacuation Plans and Procedures eTool: Emergency Standards to Portable Fire Extinguishers. https://www.osha.gov/SLTC/etools/evacuation/portable.html This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  14 LEARNING GUIDE Week No.: __3__ TOPIC/S LAYOUTING /LAYOUTING TOOLS EXPECTED COMPETENCIES Upon completing this Learning Module, the student will be able to: 1. To define and explain the importance of lay-outing and its considerations. 2. To list down the guides for a successful lay-out works. 3. Illustrate and explain the functions of various lay-outs tools. CONTENT/TECHNICAL INFORMATION INTRODUCTION: Laying out is the marking of lines, circles, arcs, and indenting location of holes on the metal surfaces. It is the transferring of information from a working drawing to metal surfaces to show the worker at the machine or bench the location and amount of metal to be cut away. Layout is important in so many ways. The ability required to run some simple machine tools. Information from the working drawing must be transferred carefully and accurately on the workpiece. Any mistake in the layout will turn out a reject product. However mistake in the layout may be corrected if there is careful inspection before work begins A. HOW IT WORKS To make good layout, the surface of the workpiece should be free from rust and oil or cleaned properly. Rough surface should be covered with white chalk to make line visible. For smooth and bright surfaces a layout dye should be used. With the use of measuring tools, scriber, and punches the lines, arcs and points are marked on the surface of the workpiece. The sharpness of the lines is well defined by the contrasting effect of the layout dye and the metal. B. GUIDELINES FOR LAYOUT WORK This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  15 1. Burrs and sharp edges must be removed. 2. Use layout coloring materials whenever necessary. 3. Always work from a given reference sides or base lines. 4. Make only one distinct line or mark. 5. Center of hole or center distances must be indented through intersections of lines. 6. Angles must be laid out with the use of a protractor. 7. Distance must be measured with an appropriate measuring instrument to approach the required accuracy. 8. Use template whenever necessary. 9. Keep scribing and indenting tools sharp. C. LAYOUT TOOLS The following tools commonly used in benchwork operations are: 1. MEASURING INSTRUMENT A. Measuring with steel rule: To measure with a steel rule, stand the rule up on its edge on the work so that the lines on the rule touch the work. The division line on the rule has a certain thickness. Always measure to the center of the line. Measure from the 1” inch mark because the end of the rule may be worn. B. Scribing Lines To draw a straight line, place the straight edge, steel rule, square or bevel protractor in the correct position and hold it against the work with the left hand. The scriber is held with the right hand like holding a pencil and lean it to one side so that the point will draw along the lower edge of the rule. Scratch one line. C. Scribing Circle with a Divider To make a circle, the divider is set first to the size of the radius, half the diameter. Hold the divider by the stem. Place one point in the prick punch mark, as the center point of the circle, to keep it from shipping and swing it to the right or left. Scratch a sharp circle (Fig.1.) Fig. 1 D. Finding Center of a Circle This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  16 To find the center of a circle, put four small prick punch marks on the circumference. Then set the divider to the radius of the circle and making the prick punch mark as center scribe for arcs. The center of the circle is between the four arcs (Fig.2) Fig.2 E. Finding the Center on the End of the round bar The center on the end of the round bar may be found in several ways. The hermaphrodite calliper is set first to the radius of the round bar and scribe four arcs while the bar s held in the vise. The center of the round bar is between the four arcs. The center square may be used to find the center of a round piece of metal. Any two lines drawn across the ends of a round piece of metal with a center square will cross the center (Fig3). Fig. 3 F. Laying Out Parallel Line with Hermaphrodite Caliper The hermaphrodite calliper may sometimes be used to layout parallel lines. The bent leg is held against the edge of the work and as the calliper is moved along. The pointed leg draws a line on the surface parallel to the edge of the work (Fig. 4) This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  17 Fig.4 CARE AND MAINTENANCE OF LAYOUT TOOLS 1. Keep point sharp by frequently giving its few strokes on the oilstone. 2. Grind point if broken off or worn out. 3. Harden or temper only if tempered part has been broken off, worn or ground away or if tools has been overheated. 4. To protect the point of the scriber, insert the point into a small cork or in a soft woodblock. 5. In storing tools, provide rack for each tool to prevent contact from one another. 6. Apply light oil on the surfaces of tools before storing. 7. Keep metal surfaces free of rust. 8. Keep screws lubricated with small quantity of lubrication or engine oil. 9. Replace all broken parts or damaged. 10. Sharpen divider points with a small oilstone; keep points towards inside of leg so points towards inside of legs will meet when divider is closed. 11. Do not use divider or scriber for any other purposes other than scribing arcs or circles or for checking measurements. 12. Do not lay dividers on bench when not in use they may be damaged by other tools; keep them in a case or wrapped in cloth. SAFETY 1. Lay-out tools like scribers, dividers, hermaphrodite callipers and other pointed tools must never be placed inside the pocket. 2. Pointed tools must be placed in a tool box with points properly guarded with cork or wooden block for their own protection as well as yours. 3. Keep tools in a place when not in use. If remain scattered on workbenches it may fail and be damaged or may cause injury. 4. Never use a tool that is not in good condition. It may ruin your work or can injured you. This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  18 PROGRESS CHECK 1. It is used to draw long arcs and circles, is also called a beam compass? a. Pointer b. Compass c. Trammel Points d. Arc Scriber 2. Which hand held punch is used to mark points when laying out patterns on sheet metal? a. Center Punch b. Prick punch c. Solid Punch d. Hollow Punch 3. To make a small indentation (centre hole) in sheet metal, a------------------ is used. a) Pencil b) Center Punch c) Needle d) Scribber 4. When a try square is used to mark a board, the: a) blade should be held firmly against the edge of the board. b) handle should be held firmly against the center of the board. c) handle should be held firmly against the edge of the board. d) handle should be held loosely against the edge of the board. 5. This tool has a sharp metal point for marking on wood, metal and plastic: a. scriber b) center punch c) file d) cold chisel Activity 2. Identification of Layouting Instrument REFERENCES Dixon,R. (1981). BenchWork: Delmar Laknepally, V., Narsampet, M. (2020). Engineering Workshop Laboratory Manual Department Of Mechanical Engineering. Retrieved From: Engineering-Workshop-i-Lab- Manual_1st%20year.pdf This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  19 LEARNING GUIDE Week No.: __4__ TOPIC/S HACK SAWING EXPECTED COMPETENCIES Upon completing this Learning Module, the student will be able to: 1. Practice safety in performing hacksawing operation 2. Develop skills and techniques in using tools used in bench work. CONTENT/TECHNICAL INFORMATION FUNDAMENTAL CONCEPTS AND PRINCIPLES: SAWING- is the process of removing small amount of chips from metallic work piece with the use of a thin short hardened blade made of a special alloy steel. HOW IT WORKS- cutting action is accomplished in three stages namely; Cutting Motion, Cutting Pressure, and Chip Removal. CUTTING MOTION- is the forward and backward movement of the saw blade which eventually causes the cutting of the material if cutting pressure is applied. CUTTING PRESSURE- is the pressure applies on the frame of the saw which transmitted to the saw blade enabling the teeth to penetrate into the work piece. CHIP REMOVAL- is the deposition of the chips in the gullet until pushed out of the cut slot or kerfs in order to prevent the blade from stacking of the work piece. The kerfs are the cut slot produced cutting which is wider than the thickness of a saw blade. ELEMENT OF THE SAW TOOTH: angles are provided to do specific functions which contribute to the effectiveness of the cutting process. 1.) Clearance Angle- is the space provided on the tooth back to come in contact with the work piece. In this way, generation of heat is reduced thus, prolonging the blade life. 2.) Lip Clearance- is the size of the saw tooth. It determines the strength of the tooth. 3.) Back Rake Angle- provides the plane which directs and controls the formation of chips. 4.) Cutting Angle- is an angle that determines the penetrating ability of the saw. It is equal to the sum of the lip angle and clearance angle. This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  20 Shapes of saw tooth: In order to obtain a good chip formation and efficient, the shape of the teeth must be adopted to the mechanical properties of the material to be cut. For ideal shape, the cutting angle should be 85 degrees Back Rake Angle 5 Degrees, Lip Angle 65 degrees and Clearance Angle should be made larger for strength. CARE AND MAINTAINANCE: 1. Never cut hardened materials or oxidized surfaces with a hacksaw. 2. Do not force the blade to cut a previously unfinished cut work piece. 3. Do not allow chips to stick to the teeth of the blade. Always clean them after using. 4. In cutting do not apply too much force to cut faster but just enough force to permit the teeth to penetrate and cut normally. 5. In storing, hand hacksaw prevent the blade to come in contact with other tools. GENERAL GUIDES ON HACKSAW BLADE SELECTION A.) MILD MATERIALS IN LARGER SECTIONS Choose blade with finer teeth to provide plenty of chip clearance and faster cutting For: Hand Blades - 14 TPI Power Blades – 4-6 TPI B.) HARDER MATERIALS IN LARGE SECTION Choose blade with finer teeth to distribute cutting load over more teeth while steel maintaining good clearance action. For: Hand Blades – 18 TPI Power Blades - 6-10 TPI C.) USUAL WORK SHAPE Choose blade to always keep two or more teeth in contact with the narrowest section coarse teeth blade straddle the work and will striped-off the teeth. For: Hand Blades – 24 TPI Power Blades – 10-14 TPI D.) PIPES, TUBING, AND CONDUIT Choose blade with finest teeth per inch to keep two or more teeth in contact with wall section. For: Hand Blades – 32 TPI Power Blades – 14-18 TPI NOTE: COARSE TEETH SAW CUTS FASTER WHILE FINE TEETH SAW CUTS SLOWER, HARD MATERIALS REQUIRE FINE TEETH WHIKLE SOFT MATERIALS REQUIRE COARSE TEETH. The blade serves as the cutting tool 1. Size : Length - 8 to 12 or 203 to 305 mm Width - ½” or 12.7 mm Thickness -.025 to.65 mm 2. Materials used: Tungsten Alloy Steel Plain Carbon Steel Molybdenum High Speed Steel This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  21 3. Types All hard, semi-flex back and flexible back 4. No. of teeth: Commonly used blades are 14, 15, 24 and 32 teeth per inch (TPI). For Metric blades the number of teeth is based the number of teeth is based on the 25 mm length such as 16, 22, and 32. 5. Type of tooth set: The Raker, Alternate, and Wavy Set SAWING PROCESS: A.) Starting a cut 1.) Check the tension of the blade. 2.) Clamp the work in the vise so that the saw will be near the jaws. 3.) Start with a light even forward stroke at an angle. When the first cut is established hold the frame firmly and saw the full width of the work. Apply pressure on the forward strokes only. 4.) Take the longest stroke possible but do not permit the blade supporting pins to touch the edge of the work. NOTE: USE THE BLADE HAVING THE PROPER NUMBER OF TEETH PER INCH TO SUIT THE JOB. FINE PITCH FOR THIN MATERIALS AND COURSE PITCH FOR THICKER ONES. B.) Number of strokes required: Under the ordinary conditions 50-60 strokes per minute is satisfactory. For carbon steel blades take the slowest speed to prevent early stripping of the teeth. However, High Speed Steel Blades can be used to maximum strokes. Hard materials require slower speed than soft materials to lengthen its life. C.) Ending the Cut- When the cut is almost completed it is a good practice to reduce speed and pressure because when the saw clears the stock forward motion will be actually greater due to the thinning of the sections being cut. Many knuckles have been skinned and hands cut because the good practice was ignored. Hold the materials to be removed with your left hand and make the last few strokes with your right hand. PROGRESS CHECK Write the correct letter of your choice on a separate answer sheet. 1. SAWING is the process of removing small amount of chips from metallic work piece with the use of a thick short hardened blade made of a special alloy steel. TRUE OR FALSE? This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  22 2. It is the transferring of information from a working drawing to metal surfaces to show the worker at the machine or bench the location and amount of metal to be cut away. A) Scribing B) Bench work C) laying-out D) Detail drawing 3. Do lay dividers on bench when not in use with other tools. TRUE OR FALSE? 4. The _______are the cut slot produced during cutting which is wider than the thickness of a saw blade. A)Back rake B) Kerfs C) Blanks D)Cutting edge 5. In chiseling the utilization of the applied force depends on the size of the ________. A)Lip angle B) Head C) Ferrule D) none of these 6. A lay-out instrument sometimes use for faster and easy scribing parallel lines, the bent leg is held against the edge of the work and as the calliper is moved along. A)Divider B) Steel Rule C) Scriber D) none of these 7 In manufacturing of chisel, ______ is heating to temperature of (2000 to 2500°F) and forming the cutting edge. A) Hardening B) Forging C) Tempering D) Quenching 8 Straight Cutting Edge chisel is used for except A)grooving B)trimming C)shearing D) chipping 9 Determines the strength of the saw tooth. A) Back rake Angle B)Lip clearance Angle C) clearance angle D) Side Cutting angle 10. In HACKSAW BLADE SELECTION we use for usual work shape for hand Blades A) 4 tpi B)12 tpi C) 18 tpi D) 24 tpi 11-13. Enumerate the 3 stages of Sawing (in proper order) 14. It is the process of allowing the cutting edge of the cold chisel to penetrate into the workpiece by driving the head vertically with several blows of the hammer. 15. Coarse teeth have 14-18 tpi is used for thin and soft materials. True or False REFERENCES LIST OF REFERENCES Dixon,R. (1981). BenchWork: Delmar Laknepally, V., Narsampet, M. (2020). Engineering Workshop Laboratory Manual This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  23 Department Of Mechanical Engineering. Retrieved From: Engineering-Workshop-i-Lab- Manual_1st%20year.pdf Occupational Safety and Health Administration (2020). Evacuation Plans and Procedures eTool: Emergency Standards to Portable Fire Extinguishers. https://www.osha.gov/SLTC/etools/evacuation/portable.html This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.  24 ABOUT THE AUTHOR/S This module is a property of Technological University of the Philippines Visayas and intended for EDUCATIONAL PURPOSES ONLY and is NOT FOR SALE NOR FOR REPRODUCTION.