Cold Chisel Angle TOOL SHARPENING GAUGE

Home , Chisel, File (tool), Steel wool, Vise

Meridian Agriculture Department Welding I METALS BOOKLET

Name: ______Date: ______

Construction Procedure: 1. Square one corner of aluminum or brass stock. 2. Measure and scribe outline on stock with awl. 3. Mark graduations with awl. 4. Cut out tool gage with hacksaw. (Use protective blocks on each side when cutting in vise.) 5. Dress to the lines with file, bevel corners. 6. Use three-square file to cut chisel vee. 7. Polish with steel wool. 8. Submit to instructor for evaluation. 9. Drill size holes ¼”, 3/16”, 1/8”, and 1/6”, may be drilled in the Twist Drill body of the gage. Cutting Angle Questions: 1. Why is aluminum easier to work than brass? o 2. Why is it important to square or make a corner 90 ? 3. Which hacksaw blade did you use; 18-24-32? Why? 4. When should you use draw filing? Cross filing? 5. Why should files always be fitted with handles?

Back Rake Angle Evaluation score sheet: Points Item Possible Earned 1. Length of gauge 10 _____ Gage can be used to measure: 2. Width of narrow 10 _____ 1. Cold chisel cutting angle 3. Width of wide end 10 _____ 2. Twist drill, cutting edge 4. Vee position for cold chisel angle 10 _____ 3. Twist drill, lip clearance 5. Angle for drill cutting edge 15 _____ Bill of Material: 6. Accuracy of the 1” and 1/2” rules 10 _____ 1-7/8” x 4-1/16” x 3/32” 7. Angle for drill lip clearance 10 _____ Aluminum, brass or mild steel 8. Correct angle and size of bevel corners 5 _____ 9. Finish 10 _____ Name______10. Attitude and work habits 10______

Date______

Grade______

3 HACKSAWS

1. Hand hacksaw

a. Frames (1) Adjustable – This is the most popular frame for general use. They vary in depth from 2- 1/2” to 3-1/2” and will take blades from 8” to 12” in length. By loosening the wing-nut, the mounting posts may be turned so that the blade will cut at right angles to the frame. (2) Solid – Frames may be had that vary in depth and length. They remain very rigid and for specialized work are very desirable.

b. Blades (1) A blade should be selected that will be best suited to the work being done. In most Cases, it is desirable to select 10” to 12” blades for use in adjustable frames. (2) The blade should have enough teeth per inch so that two or more are in contact with the metal at all times. Standard blades are 7/16” to 9/16” wide with 14 to 32 teeth per inch and 8” to 12” long. Blades with 18, 24 or 32 teeth per inch are used most.

2. Cutting metal with a hacksaw

a. Mount the blade in the frame so that the teeth point forward. b. Tighter the tension out so that when struck with a piece of metal, the blade gives a slight ring. c. Clamp the work securely so that two or more teeth are in contact with the metal at all times. d. Saw close to the vice to prevent vibration. e. Thin material may be placed between two blocks of wood before sawing. f. Grip saw firmly; one hand on handle and the other holding front of frame. Make each stroke go full length of blade. g. Apply pressure on only the forward stroke then lift slightly on the return stroke when sawing hard metal. h. Always start a new cut when replacing a blade. i. Use approximately 35 to 50 strokes per minute – 80 strokes should be the maximum. Hard materials overheated and dull blade when sawed too fast.

3. Most common causes of blade breakage or failure

a. Using a saw with large teeth to saw thin metal. b. Using too much pressure. c. Sawing too fast. d. Using short strokes, causing excess wear and loss of set. e. Insufficient tension on blade f. Failure to give work proper support. g. Failure to hold saw firmly and push straight forward on the cutting stroke and return straight back.

4. Filling Cold Metal

The file is used for smoothing and shaping metals. Shaping actually includes three types of file use: sharpening of tools, smoothing metal surfaces, and cutting metal to the desired form and dimensions. A regular mill file can also be used to test the hardness of metal. The degree of hardness will determine the type of metal cutting tool and/or the type of hacksaw blade to use for making the cut.

5 a. Files are selected according to their many uses. The use of a file determines the size, type of teeth, coarseness, and shape. (1) File Sizes – File sizes are determined by the length of the file ( in inches) excluding the tang or the distance from the point to the heel. A 10-inch mill file is used for general purposes. A 12-inch flat file is best for rough work and will last longer than a 10-inch file.

(2) File Teeth – There are two major kinds of file teeth, single-cut and double cut. Single- Cut files have chisel-like teeth running at an angle across the belly and body of the file. Double-cut files have two sets of teeth or chisel cuts that cross each other. Single-cut files cut slower then double-cut files, and they leave a smoother surface.

(3) Grades of Teeth Coarseness - The grade of coarseness is determined by the distance between the rows of teeth. For example, the longest spacing is called rough, and the least spacing is dead-smooth. Naturally, the coarseness changes with the length. A long file is coarser than a short file.

TEETH SPACING OF SINGLE-CUT FILES The most commonly used files are the bastard, second-cut, and smooth. Rough, coarse, and dead-smooth files are used for special work.

(4) File Shapes – The shape or style is also determined by the different uses. The most common are mill, flat, square, round, half-round, and taper or three corner files. A description of these files is as follows:

(a) Mill files are made only with single-cut teeth and range in size from 4 to 16 inches. They are used for drawfiling and finishing work such as finishing brass and bronze metals.

(b) Similar to the mill file and are the most commonly used of all files for general work.

(c) Square files have four filing edges instead of two as round on the mill and flat files. They are tapered or blunt and double-cut. This kind of file is used to filing corners and slots and for surface filing.

(d) Round files are single or double cut. They are used for enlarging holes, filing curves, and forming fillets. These files are tapered from shoulder or heel to point.

(e) Half-round files have one flat side and one partly round side (about one-third of a circle). This type of file is double-cut, and it can be used to file either flat or curved surfaces.

(f) Tapered files are found in many shapes. The Triangle, contour, and cross-cut files are the most popular. They are double cut and are used to file corners that are less than 90 degrees and to file saws.

There is a correct way and many incorrect ways to hold a file for both heavy and light filing:

(1) Heavy filling – The handle is held in one hand by placing the thumb or forefinger on top of the file handle and gripping the point with the fingers and back part of the thumb.

Tang Heel Body Bell Point

Length

8 Wood File Handle (for safety)

(2) Light Filing - The handle may be held the same way as in the heavy filing method. The file point is held between the first two fingers and thumb, applying light to moderate pressure as needed.

c. The steps to follow when using a file to shape metal are:

(1) Clamp the stock (metal) slightly above the jaws of the vise to eliminate vibration while filing. The area being filed should be about elbow height or slightly below. Chattering can be reduced or almost eliminated if the stock is placed just above the jaws of the vise.

Machinist Bench Vise

(2) Select the proper type file to cut the stock. For example, if the surface is to be filed flat, select a flat file.

(3) Stand slightly to one side of the work, yet facing it so that the right amount of pressure can be applied on the forward stroke.

(4) Use moderate speed strokes. However, hard metal is filed slower with more pressure than mild

9 or soft metal. About 30 strokes per minute may be appropriate.

(5) Except for filing, hold the file at a 90-degree angle to the side of the stock when making filing strokes on flat metal.

(6) Make a slow, full-length stroke by placing the file on the stock and pushing it forward; lift it on the back stroke. Moving the file back, permitting it to slide over the metal, will dull the teeth faster than pushing the file forward. If there is a possibility of the file slipping off the stock on forward stroke and marking or damaging the jaws of the vise, the stock should be clamped between two pieces of board.

(7) Check the stock with a square during the filing process to see if a proper cut is being made. A 90-degree cut is easily checked by using a try square. It may be necessary to file the stock by holding and pushing the file in a diagonal position to keep the surface flat.

Clean the file periodically while it is being used with a wire brush or file card. Hard- to-get chips can be removed with a clean wire. Some of the chips can be removed by tapping the file on the work bench. Cleaning can be aided by starting the body at a different place on each forward stroke.

File Card: used to clean files from metal filings.

d. Draw filing is a method of filing long, flat surfaces and rods. It is also used to smooth rods that may require considerable hammering. The method is as follows:

(1) After the stock has been clamped high enough in the vise to clear the fingers grasp each end of the File, placing it on the stock with each thumb clearing the stock by about ¾ inch. Use a mill file which is single-cut.

(2) Apply steady pressure as the file is pushed forward. Release the pressure on the return stroke. Actually, when draw filing, the file is pushed sideways for cutting. Always hold the file flat while moderately slow strokes are being made on the stock. It may be necessary to clean the file often when draw filing mild or soft metals.

e. It is important to test metal for hardness before attempting to file it. Generally, it is advisable to place the metal stock in a vise in order to run the file over its surface an inch or two to determine metal hardness. Cutting characteristics of five different types of metal include:

(1) Extremely Hard Metal – The file will slide over the metal, leaving the file dull and shiny. The file must be harder than the material being cut, and it should not be used on hardened steel.

(2) Hard Metal – The file may barely cut into the metal, but it is dulled if considerable pressure is applied.

(3) Medium Hard Metal – This type of metal can be filed without dulling the file immediately.

(4) Soft Metal – The file teeth bite into the metal very easily and become clogged with metal particles. Soft metal is cut without dulling the file. Very little pressure is applied to the file when cutting soft Metal.

(5) Cast Iron – The outer surface of cast iron is considered very hard; therefore, an old file should be used to cut through the outer surface before using a new file. If scale is present, it should be removed with a chisel and hammer before attempting to file the surface.

f. A file requires special care if it is to be used over a long period of time. The following suggestions may be observed:

(1) Store files in racks away from other metals. If they rub or fall against other files or tools, the teeth may be damaged. Files are very brittle and may be broken if allowed to fall on concrete floors or other metals.

(2) Keep files away from oils, paint, and caulking compounds, as these materials clog the teeth. Also, the file may corrode if placed in a humid or moist location.

(3) A file should never be used without a well seated handle on the tang. Recheck the seating before storing.

GROUP 8 - EXERCISE B - GRINDING A TWIST DRILL

Reference Reading: Shopwork on the Farm, Grading Standard: Accuracy 40, Neatness “Sharpening and Fitting Tools” the section 10, Test Results 40. “Sharpening Twist Drills”; Farm Mechanics Equipment and Materials: Text and Handbook, “Repairing and Sharpen- a. Goggles ing Tools”; How to Run a Lathe, “Drilling, b. Drill grinding gauge or protractor & scale Reaming and Tapping.” c. Access to tool grinder and cooling water. d. Dull drill, larger diameters preferred. Procedure: Steps:

11 1. Inspect grinding wheel. Key Points: a. If wheel is worn/irregular, ask instructor 1. Should be straight, smooth, and true. to dress it. a. 2. Inspect dull drill with gauge to determine: 2. See Figure 8.9. a. If lips were previously ground to correct a. At 59 degree angle. angle. b. Measure length of each with gauge. b. Lips were ground to same length. c. Check with gauge. c. Proper clearance angle was ground. 3. Estimate angle with eye. (Figure 8.10) 3. Assume 59 degree angle with drill axis in relation a. If original angle was correct, bring edge to face of stone. parallel to face of stone. a. Hold drill level. b. b. Rotate drill until shortest cutting edge is nearest stone and is level. c. c. Try a dry run of step 4 with stone stopped.

Back Rake Angle

4. Grind the first edge. 4. Move drill in and touch stone lightly. a. Adjust axis angle accurately. a. Watch sparks to tell where drill touches. b. Grind clearance angle by lowering shank of drill. b. Lower shank about 12 degrees and swing to left 4 – 8 degrees and describe a ¼ circle as shown in Figs.8.11 and 8.13 with drill point as pivot. 5. Check with drill gauge. 5. For lip and axis angle. a. For clearance. b. Compare lip length with other lip. 6. Grind other lip same way. 6. Check often. 7. Cool drill often by dipping in water, especially

14 if carbon steel drill. If colors show on carbon steel, the job is ruined.

Drill Press Operation

I. SAFE OPERATIONAL PROCEDURES:

1. General Drilling - - a. Use a drill gauge to determine drill size. b. Be sure drill is sharp and ground properly. c. Be sure the material is clamped firmly. d. Feed drill into material at a constant rate. e. When drilling round stock, use a “V” block vise. f. Place work on a block of wood to prevent damage to the table.

2. Metal drilling - - a. Use a scribe or scratch awl to mark point for punch mark. b. Center punch a mark large enough to receive the point of the drill. c. Select the exact size of drill. d. Use a pilot hole for holes larger than ½”. e. Select the proper drill speed for drill size. f. Use cutting oil when drilling into steel. g. When drilling holes to be tapped, be sure to use the exact drill for the size tap

16 selected. (See drill and tap charts.) the hole should be approximately 1/16” smaller than the tap size.

II. GENERAL SAFETY PRACTICES:

1. Wear eye protection at all times. 2. Do not operate the drill press without permission from your instructor. 3. Clamp the material to be drilled securely to the table. 4. Place the long end of the piece being drilled to the left so it will hit the post and not the operator should the material slip and start rotating. 5. Be sure chuck is tight on drill and that the drill and chuck match. 6. Always remove the chuck wrench from the chuck immediately after using it. 7. Be sure drill is sharp and operating at proper speed. 8. Never wear gloves while operating the drill press. They may get caught. 9. Do not wear loose-fitting clothes. 10. Do not feed the drill faster than it can easily cut. 11. Remove the chips from the machine with a brush. 12. Use care in reaching around the machine. 13. Keep long hair tied back or covered to keep it from getting wrapped around the chuck. 14. Do not talk to anyone while operating the machine. 15. Do not drill into a container than may have contained gasoline or other flammable materials. 16. Support long materials being drilled. 17. Slow drill feed when it is breaking through the material to finish the hold 18. Hold round stock in a “V” block 19. Clamp sheet metal between two blocks of wood and drill through wood and metal.

COLD CHISEL

Head Stock Flat Bevel Cutting Edge

IDEAL: 1. 70 degree angle 2. Each side the same length 3. No burns 4. No extra grind faces 5. Point in the center Each grinding surface straight

Emery Wheel Steel Wire Dresser Bruch

GRINDER

I. SAFE OPERATIONAL PROCEDURES:

1. Tool Sharpening

a. Selecting the grinding wheel

1. Select a 60-grit wheel for general tool sharpening. 2. A soft grinding wheel is recommended for grinding hard materials. 3. The grinding wheel should fit inside the housing. 4. The arbor hole size should be.002 inches larger than the shaft size. 5. The grinding speed should not exceed the speed listed on the side of the grinding wheel.

18 b. Maintaining the grinding wheel

1. Use a wheel dresser to remove the glaze on the wheel after grinding soft material. 2. Use a wheel dresser for straightening a grooved, rounded or out-of-round wheel. 3. Before dressing the wheel, adjust the tool rest on the grinder to a point even with the center of the wheel. 4. Start the grinder. Place the wheel dresser on the tool rest gripping it with both hands. 5. Move the wheel dresser back and forth across the wheel. Do not let the dresser pass of the edge of the wheel. 6. Remove just enough material to clean and straighten the wheel. 7. Use a combination square to ascertain if the face of the wheel is square with the side. c. Sharpening a tool

1. Adjust the tool rest so that it is not more than 1/8 inch from the wheel and slightly above the center. 2. Stand to one side and start the grinder. 3. Allow the machine to come up to speed before you start grinding. 4. Carefully place and tool against the grinding wheel, so it’s cutting edge is against the direction of rotation. 5. Move the tool slowly across the face of the wheel. 6. Do not allow the tool to overheat. Dip it in water or use a very light feed and stop to allow it to cool in the air.

III. GENERAL SAFETY PRACTICES:

1. Wear eye protection at all times. 2. Do not operate the grinder with permission from your instructor. 3. Be sure the housing is in place around the grinding wheel. It is there to protect you in case the grinding wheel should break. 4. Do not use a wheel that vibrates excessively. 5. Never use a grinding wheel that you suspect may be cracked or broken. 6. Do not use the grinder if the light is not adequate. 7. Wear a face guard even though the grinder has a glass shield. 8. Do not hold material being ground in such a way that your fingers may contact the wheel surface. 9. Avoid using the side of the wheel for rough grinding. This may place too much stress on the wheel and cause it to break. 10. Do not force material into the wheel. 11. If the wheel cuts slowly or vibrates because of uneven wear, use a wheel dresser to expose a new cutting surface. 12. Do not operate the grinder if another person is standing nearby. 13. Never remove the paper from the sides of the grinding wheel. 14. Do not use a grinding wheel that is worn to less than ½” its original diameter. 15. Do not leave the grinder without turning it off.

III. COMPLETION QUESTIONS:

1. Soft stones are recommended for grinding ______materials.

2. The arbor hold size should be ______inch(es) larger than the shaft size.

3. A ______is used to straighten a grooved, rounded or out-of-round

grinding wheel.

4. The wheel dresser should not pass off the ______of the grinding wheel.

5. A ______can be used to determine if the face of the wheel is square

with its side.

6. Before sharpening a tool, adjust the tool rest so it is not more than _____ inch(es) from the

wheel.

7. The ______of the tool being sharpened should be against the

direction of rotation.

8. The tool should be moved slowly across the ______of the wheel.

9. The tool can be dipped in ______to keep it from overheating.

10. You should stand ______

when you start the grinder.