Finals Learning Module 01: Metal Cutting Tools PDF
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Philippine State College of Aeronautics
Femkee C. Limaima
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Summary
This document is a learning module on metal cutting tools, specifically focusing on hand tools used in the aviation industry. It covers various types of tools, their functions, and safety precautions. It also contains a table of contents and references.
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**FINALS LEARNING MODULE 01:** **Metal Cutting Tools** **HANDTOOLS** ***PREPARED BY*** ***FEMKEE C. LIMALIMA*** ***InET-AVT Instructor*** **TABLE OF CONTENTS** ***CONTENT*** ***PAGES*** ***Reference*** ***TIME ALLOTED*** -----------------------------------...
**FINALS LEARNING MODULE 01:** **Metal Cutting Tools** **HANDTOOLS** ***PREPARED BY*** ***FEMKEE C. LIMALIMA*** ***InET-AVT Instructor*** **TABLE OF CONTENTS** ***CONTENT*** ***PAGES*** ***Reference*** ***TIME ALLOTED*** ------------------------------------------ ------------- ----------------- -------------------- Table of Content and Table of References 2 1-4 10min Learning Objectives 3 1-4 50min Discussion 4-12 3-4 240min Enrichment Activity 13 1-4 120min **TABLE OF REFERENCES** **No.** --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- --------- Federal Aviation Administration (2018)**.** *Aviation maintenance technician handbook--General (FAA-H-8083-30A).* Retrieved from **1** Kazimieras Simonavičius University (2017). *Maintenance practices*. Retrieved from **2** Crane, D. (2006). *Aviation mechanic handbook* (5^th^ ed.). Aviation supplies and academics **3** Kroes, J. & Rardon, J. (1993). *Aircraft basic science* (7^th^ ed.). McGraw-Hill Book Co. **4** This module discusses the common and most frequently used metal cutting tools in aviation industry. This module discusses the different types and functions of metal cutting tools, it also discusses the safety precautions on using these type of handtools. **LEARNING OUTCOMES** **Cutting is a process of shearing away or removing portions of a material. The material removed can be a large piece, such as a piece of sheet metal cut into two parts, or it can make a form of a number of small particles or chips, such as those made by hacksaw. To cut a material, the tool must be harder than the material to be cut.** ***Hand snips*** **Snips are used for cutting sheet metal and steel of various thickness and shapes.** Straight, curved, hawksbill, and aviation snips are in common use. Aviation snips are designed especially for cutting heat treated aluminum alloy and stainless steel. They are also adaptable for enlarging small holes. The blades have small teeth on the cutting edges and are shaped for cutting very small circles and irregular outlines. The handles are the compound leverage type, making it possible to cut material as thick as 0.051 inch. The handle of these snips are color coded. The *yellow handles cut straight*, handles with color *red cut to the left* and *green handles cut to the right.* Unlike the hacksaw, snips do not remove any material when the cut is made, but minute fractures often occur along the cut. Therefore, cuts should be made about 1⁄32 inch from the layout line and finished by hand filing down to the line. **Safety and Care** Learn to use snips properly. They should always be oiled and adjusted to permit ease of cutting and to produce a surface that is free from burrs. If the blades bind or if they are too far apart, the snips should be adjusted. Remember the following safety tips: - Never use snips as screwdrivers, hammers, or pry bars. They break easily. - Do not attempt to cut heavier materials than the snips are designed for. Never use tin snips to cut hardened steel wire or other similar objects. Such use will dent or nick the cutting edges of the blades. - Never toss snips in a toolbox where the cutting edges can come into contact with other tools. This dulls the cutting edges and may even break the blades. - When snips are not in use, hang them on hooks or lay them on an uncrowded shelf or bench. ***Chisels*** **The chisel is a basic metal-cutting tool. The chisel consists of a steel tool with a hardened point. The shearing force is usually applied by a hammer. Cutting with chisel is called *chipping*.** **Types of chisel** ***Flat Chisel-* made of a piece of a hardened steel that is ground with a cutting angle of 60°-70°. The cutting edge is ground to a convex shape to concentrate the force of the hammer blows at the point the cut is being made.** ***Cape Chisel-* cape chisels have a narrow cutting edge used to remove the head of a solid rivet after the head has been drilled through.** ***Diamond Point chisel-*these type of chisels are forged to sharp-cornered square, and the end is ground to an acute angle form a sharp pointed cutting edge.** ***Round nose Chisel-* these chisels look much like diamond point chisels except the cutting edge is ground to a circular point.** The type of chisel most commonly used is the flat cold chisel, which serves to cut rivets, split nuts, chip castings, and cut thin metal sheets. The cape chisel is used for special jobs like cutting keyways, narrow grooves, and square corners. Round-nose chisels make circular grooves and chip inside corners. Finally, the diamond-point is used for cutting V-grooves and sharp corners. *Precautions on using Chisels* As with other tools, there is a correct technique for using a chisel. Select a chisel that is large enough for the job. Be sure to use a hammer that matches the chisel; that is, the larger the chisel, the heavier the hammer. A heavy chisel will absorb the blows of a light hammer and will do virtually no cutting. When using a chisel for chipping, always wear goggles to protect your eyes. If others are working close by, see that they are protected from flying chips by erecting a screen or shield to contain the chips. Remember that the time to take these precautions is before you start the job. **Hacksaw** Hand sawing of a metal is done with a hacksaw. The common hacksaw has a blade, a frame, and a handle. The handle can be obtained in two styles: pistol grip and straight. A hacksaw uses a narrow replaceable blade held under tension in a steel frame. The blades are available in 10-12 inch lengths and pitches of 14, 18, 24, and 32 teeth per inch. The number of teeth to be use depends on the type of metal to be cut. A blade marked 1032 would be in 10 inches long and have 32 teeth per inch. A 1218 would have 18 teeth per inch and 12 inches long. A blade with 14 teeth per inch is preferred when cutting machine steel, cold rolled steel, or structural steel. A blade with 18 teeth per inch is preferred for solid stock aluminum, bearing metal, tool steel, and cast iron. Use a blade with 24 teeth per inch when cutting thick-walled tubing, pipe, brass, copper, channel, and angle iron. Use the 32 teeth per inch blade for cutting thin-walled tubing and sheet metal. The hacksaw blade should be installed with the teeth pointing forward. Cutting action takes place on the forward movement of the saw. To prevent excessive wear, pressure on the blade should be lightened during the backstroke. ***Hacksaw Safety*** The main danger in using hacksaws is injury to your hand if the blade breaks. The blade will break if too much pressure is applied, when the saw is twisted, when the cutting speed is too fast, or when the blade becomes loose in the frame. Additionally, if the work is not tight in the vise, it will sometimes slip, twisting the blade enough to break it. **Files** Files are used by technicians to cut and shape metal. Files are used to square ends, file rounded corners, remove burrs from metal, straighten uneven edges, file holes and slots, and smooth rough edges. Files consist of hardened metal shapes with a number of chisel like teeth cut into them. Files are categorize by length, shape type of cut and coarseness of cut **Most commonly used Files** *Hand files---*These are parallel in width and tapered in thickness. They have one safe edge (smooth edge) which permits filing in corners, and on other work where a safe edge is required. Hand files are double cut and used principally for finishing flat surfaces and similar work. *Flat files---* These files are slightly tapered toward the point in both width and thickness. They cut on both edges as well as on the sides. They are the most common files in use. Flat files are double cut on both sides and single cut on both edges. *Mill files---*These are usually tapered slightly in thickness and in width for about one-third of their length. The teeth are ordinarily single cut. These files are used for drawfiling and to some extent for filing soft metals. *Square files---*These files may be tapered or blunt and are double cut. They are used principally for filing slots and key seats, and for surface filing. *Round or rattail files---*These are circular in cross section and may be either tapered or blunt and single or double cut. They are used principally for filing circular openings or concave surfaces. *Triangular and three square files---*These files are triangular in cross section. Triangular files are single cut and are used for filing the gullet between saw teeth. Three square files, which are double cut, may be used for filing internal angles, clearing out corners, and filing taps and cutters. *Half-round files---*These files cut on both the flat and round sides. They may be single or double cut. Their shape permits them to be used where other files would be unsatisfactory. *Lead float files*---These are especially designed for use on soft metals. They are single cut and are made in various lengths. *Warding file---*Rectangular in section and tapers to narrow point in width. This file is used for narrow space filing where other files cannot be used. *Knife file---*Knife blade section. This file is used by tool and die makers on work having acute angles. *Wood file*---Same section as flat and half-round files. This file has coarser teeth and is especially adaptable for use on wood. *Vixen (curved-tooth files)---*Curved-tooth files are especially designed for rapid filing and smooth finish on soft metals and wood. The regular cut is adapted for tough work on cast iron, soft steel, copper, brass, aluminum, wood, slate, marble, fiber, rubber, and so forth. The fine cut gives excellent results on steel, cast iron, phosphor bronze, white brass, and all hard metals. The smooth cut is used where the amount of material to be removed is very slight, but where a superior finish is desired. ***Methods on using Files*** ***Straight filing-* this process consists of pushing the file lengthwise across the metal applying the sufficient pressure to make the file cut** ***Draw filing-* consists of grasping the file at each end and pushing or pulling it across the work to produce a fine finish.** *Rounding corners-* The method used in filing a rounded surface depends upon its width and the radius of the rounded surface. If the surface is narrow or only a portion of a surface is to be rounded, start the forward stroke of the file with the point of the file inclined downward at approximately a 45° angle. Using a rocking chair motion, finish the stroke with the heel of the file near the curved surface. This method allows use of the full length of the file. *Removing burred or slivered edges-* Practically every cutting operation on sheet metal produces burrs or slivers. These must be removed to avoid personal injury and to prevent scratching and marring of parts to be assembled. Burrs and slivers will prevent parts from fitting properly and should always be removed from the work as a matter of habit. *Care of Files* There are several precautions that any good craftsman will take in caring for files. 1\. Choose the right file for the material and work to be performed. 2\. Keep all files racked and separated so they do not bear against each other. 3\. Keep the files in a dry place---rust will corrode the teeth points, dulling the file. 4\. Keep files clean. Tap the end of the file against the bench after every few strokes, to loosen and clear the filings. Use the file card to keep files clean---a dirty file is a dull file. A dirty file can also contaminate different metals when the same file is used on multiple metal surfaces. ***Safety*** Never use a file unless it is equipped with a tight-fitting handle. If you use a file without the handle and it bumps something or jams to a sudden stop, the tang may be driven into your hand. To put a handle on a file tang, drill a hole in the handle, slightly smaller than the tang. Insert the tang end, and then tap the end of the handle to seat it firmly. Make sure you get the handle on straight. **Hole Cutting Tools** **Twist Drills** **These drills are used to make holes on metal parts to make attachments and to joint parts in an assembly. They are available in two materials carbon steel and high-speed steel. Carbon steel cost less and have shorter life than high speed steel drills and therefore, they have limited use. High speed steel drills are made of alloy steel and maintain their sharpness even when they are hot. They are available in three groups of sizes: number, letter and fraction.** Electric and pneumatic power drills are available in various shapes and sizes to satisfy almost any requirement. Pneumatic drills are preferred for use around flammable materials, since sparks from an electric drill are a fire or explosion hazard. The principal parts of a twist drill are the shank, the body, and the heel. The drill shank is the end that fits into the chuck of a hand or power drill. The body of the drill is the part between the point and he shank. It includes the spiral flutes, the land, and the margin. The point of the drill includes the entire coned shaped cutting end of the drill. The point includes the cutting edge or lips, which are sharpened when the drill is ground. The twist drill should be sharpened at the first sign of dullness. For most drilling, a twist drill with a cutting angle of 118° (59° on either side of center) will be sufficient; however, when drilling soft metals, a cutting angle of 90° may be more efficient. Typical procedures for sharpening drills are as follows: 1\. Adjust the grinder tool rest to a convenient height for resting the back of the hand while grinding. 2\. Hold the drill between the thumb and index finger of the right or left hand. Grasp the body of the drill near the shank with the other hand. 3\. Place the hand on the tool rest with the centerline of the drill making a 59° angle with the cutting face of the grinding wheel. Lower the shank end of the drill slightly. 4\. Slowly place the cutting edge of the drill against the grinding wheel. Gradually lower the shank of the drill as you twist the drill in a clockwise direction. Maintain pressure against the grinding surface only until you reach the heel of the drill. 5\. Check the results of grinding with a gauge to determine whether or not the lips are the same length and at a 59° angle. **Reamers** Reamers are used to smooth and enlarge holes to exact size. Hand reamers have square end shanks so that they can be turned with a tap wrench or similar handle. A hole that is to be reamed to exact size must be drilled about 0.003 to 0.007 inch undersize. A cut that removes more than 0.007 inch places too much load on the reamer and should not be attempted. **Countersink** **A countersink is pointed cutting tool designed to produce a conical-shaped hole in a metal of in other material to fit the head of the countersunk head rivet or screw. The countersunk hole forms the mouth of a previously drilled straight hole.** **A countersink with stop cuts a countersink hole with correct depth.** **Counterbore** **A counterbore is designed to a second hole that is larger than the first and concentric with it. The pilot of the counterbore fits to the first hole drilled and keeps the tool concentric with it. The purpose of counterboring is to make a recess for a bolt head.** **Hole saw** **Used to cut large holes in thin sheet metal or wood. Saw diameters can be installed ranges from 9/19 inch to 4 inches. A shank fits into the drill press or hand frill motor and the pilot drill has short section of flutes with a longer smooth shank.** **Fly cutter** **Used to cut large holes in thin sheet metal but not limited to specific size holes. a cutting tool is mounted in the arm of the fly cutter, and the arm is adjusted so the tip of the cutter is exactly the radius of the desired hole from the center of the pilot drill.** **Operate the drill press at a slow speed and feed the cutter into the work very slowly and carefully so it cuts rather grabs.** **Taps and Dies** **Taps and Dies are used for cutting threads. The Tap is employed to cut threads inside a drilled hole, and the Die is used to cut threads on a metal rod.** Hand taps are usually provided in sets of three taps for each diameter and thread series. Each set contains a taper tap, a plug tap, and a bottoming tap. Dies may be classified as adjustable round split die and plain round split die. The adjustable split die has an adjusting screw that can be tightened so that the die is spread slightly. By adjusting the die, the diameter and fit of the thread can be controlled. ***Student Activity: At the end of the discussion students are required to answer the following questions. Answers send to your respective google class codes in google classroom.*** **Name:\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date:\_\_\_\_\_\_\_\_\_\_** **Year and Section:\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_** **General Instructions: Submit your activity in pdf format or scanned/picture for hand written. Include honesty clause in your submission. Make sure to submit on or before deadline, late submission is subject to penalty or deduction of score.** **I.** 1. **What are the different types of metal cutting tools and describe their functions.** 2. **What are the three colors of aviation snips and direction of cuts?** 3. **Differentiate countersink and counterbore.** 4. **Discuss How to install a hacksaw blade.** 5. **What are the use of Taps and Die?** 6. **What are the methods of using a file, discuss each?** **II.** 1. **Enumerate the types of chisel.** 2. **Enumerate the commonly used files.** 3. **Enumerate the safety precautions of the following tools.** a. **Hand snips** b. **Chisel** c. **Hacksaw** d. **Files** *Honesty Clause* I am expected to display the highest degree of honesty and professionalism in my class work, requirements, assignments and activities. I affirm that all of these are not given or received from any unauthorized help. I understand that if plagiarism is found on my work, my instructor will follow the procedures on academic dishonesty set forth by Philippine State College of Aeronautics. \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Name and Signature