MODULE INTRODUCTION TO HAND TOOLS. (00103 LESSON 2 of 2) SLIDE PRESENTATION

Transcription

1 MODULE INTRODUCTION TO HAND TOOLS (00103 LESSON 2 of 2) SLIDE PRESENTATION

2 SLIDE 33A SQUARES Squares are used for marking, checking, and measuring. The common squares are the carpenter s square, rafter angle square, try square, and combination square.

3 SLIDE 33B Figure 32 Types of squares.

4 SLIDE SQUARES The carpenter s square is used mainly to square up sections of work such as wall studs or sole plates. It has a 24 blade and a 16 tongue, forming a right (90 ) angle. The blade and tongue are calibrated in inches and fractions of inches. One side contains tables for calculating the lengths of rafters, as well useful formulas and other data. The rafter angle square, or speed square, is specifically designed for laying out roofs and stairs. It is a combination tool consisting of a protractor, try square, and framing square. The try square is a fixed 90 angle used to lay out cutting lines, check the squareness of adjoining surfaces and joints, and to check lumber to see if it is warped or bowed. Figure 33 Marking a line for cutting.

5 SLIDE SQUARES The combination square has a moving head that can be slid along the blade. A combination square can be use as a straightedge, or to mark 45 and 90 angles. Figure 34 Using a combination square to mark a 90 angle. Figure 35 Using a combination square to mark a 45 angle.

6 SLIDE PLUMB BOB A plumb bob is a pointed weight that uses the force of gravity to establish plumb. Some chalk lines are made to double as plumb bobs. Figure 36 Plumb bobs.

7 SLIDE PLUMB BOB When the plumb bob is allowed to hang freely, the string is plumb, so it can be used to make sure a door jamb or wall is plumb, or to locate a point directly under another point. A plumb bob should never be dropped, because the point could be damaged, resulting in inaccurate readings. Figure 37 Proper use of a plumb bob.

8 SLIDE CHALK LINES A chalk line is a string coated with chalk. It is used to mark a straight line. Mechanical chalk lines like the ones shown are filled with chalk and automatically chalk the line for each use. Some mechanical chalk lines are pointed, so they can double as a plumb bob. Figure 38 Mechanical self-chalkers.

9 SLIDE 39A CHALK LINES In use, the line is stretched tightly between two points, and then snapped to mark a straight line. Keep the chalk line dry. Damp chalk is not useable. Play video on Slide 39B. Figure 39 Proper use of a chalk line.

10 SLIDE 39B CHALK LINES

11 SLIDE 40A UTILITY KNIVES Utility knives are used for such purposes as cutting roofing felt and shingles, floor coverings, fiberboard, and gypsum board. A utility knife has a razorlike blade and a handle that is about 6 long. The case is made of metal or plastic. The handle is in two halves, held together by a screw. The handle is separated to replace the blade. Many models have a retractable blade. The blade can be locked in any of three positions: closed, half-extended, and fully extended. When using a utility knife, lock the blade in the open position and place some scrap material under the object you are cutting to protect the surface under the object. Figure 40 Utility knife.

12 SLIDE 40B It is not necessary to sharpen the blade. It is easy and inexpensive to replace. Be sure to keep the blade closed and locked when not in use.

13 SLIDE 41A SAWS There are many types of handsaws. The main differences lie in the shape, number, and pitch of their teeth. Generally, the fewer the points, or teeth per inch, the coarser and faster the cut. More teeth mean finer cuts. A backsaw is used to cut joints, especially miter and tenon joints. The compass, or keyhole, saw can fit into tight places. It is often used to cut curves and holes in lumber, plywood, and drywall. A coping saw has a very narrow, flexible blade. It is used to fit irregularly shaped moldings together. The drywall saw is a long, narrow saw used to cut softer building materials such as drywall. A hacksaw is used to cut metal such as pipe. The teeth of a hacksaw blade must face away from the handle. The handsaw is used to cut lumber.

14 SLIDE 41B Figure 41 Types of saws.

15 SLIDE 42A SAWS The crosscut handsaw is designed to cut across the grain of the wood. The ripsaw is designed to cut with the grain. The crosscut has more teeth per inch than the ripsaw. When cutting with a handsaw, make sure the wood is well supported. To use a ripsaw properly, mark and start a ripping cut the same way you would start cutting with a crosscut saw. Always brace yourself when sawing so you are not thrown off balance on the last stroke. Play video on Slide 42B. Figure 42 Kerf cut with the wood grain.

16 SLIDE 42B SAWS

17 SLIDE FILES AND RASPS Files and rasps are used to cut, smooth, or shape metal parts and to sharpen tools. Figure 43 Types of files, rasps, and handles.

18 SLIDE FILES AND RASPS Files and rasps are usually made of hardened steel. Files have slanting rows of teeth; rasps have individual teeth. Both are sized by the length of the body. Figure 44 Parts of a file.

19 SLIDE FILES AND RASPS There is a specific type of file for each type of material. Generally, files for soft material have sharp, widely spaced teeth. Files for hard materials have teeth that are blunter and closer together. Files are classified by the cut of their teeth; rasps are classified by the size of their teeth. Type Rasp-cut file Single-cut file Double-cut file Description The teeth are individually cut; they are not connected to each other. Has a single set of straight-edged teeth running across the file at an angle. Two sets of teeth crisscross each other. Types are bastard (roughest cut), second cut, and smooth. Uses Gives a very rough surface. Used mostly on aluminum, lead, and other soft metals to remove waste materials. Also used on wood. Used to sharpen edges, such as rotary mower blades. Used for fast cutting. Table 1 Types and Uses of Files

20 SLIDE FILES AND RASPS When using a file or rasp, mount the work in a vise at about elbow height. Place one hand on the handle and the other on the end of the file. Always attach a handle to the file before using it. Figure 45 Proper use of a file.

21 SLIDE FILES AND RASPS To clean a file, brush filings out of the teeth using a file card, pushing in the same direction as the line of the teeth. Figure 46 File card.

22 SLIDE 48A CLAMPS Clamps come in a wide variety of types to serve different purposes, and are sized by the maximum opening of the jaws. The depth of the throat determines how far from the edge of the work the clamp can be placed. C-clamps are used primarily to hold metal. The locking C-clamp operates like locking pliers. The handles of a spring clamp are squeezed to open it. When released, the jaws will clamp securely on the work. The bar clamp uses a fixed jaw and a sliding jaw. The object to be clamped is placed between the two jaws. The sliding jaw is moved against the work and the setscrew tightens the jaws in place. The pipe clamp looks like a bar clamp and uses a screw handle to tighten the work once the movable jaw has been positioned against the work.

23 SLIDE 48B Hand-screw clamps are often used to hold wood while it is being glued. It has wooden jaws and can spread pressure over a wide area. The jaws work independently, so the clamp can be used on angled work. A web clamp is used to apply even pressure around a large object. The jaws are tightened by ratchet action. A Quick Grip bar clamp allows you to squeeze up to 600 pounds of force with one hand.

24 SLIDE 49 Figure 47 Types of clamps. (1 of 3)

25 SLIDE 50 Figure 47 Types of clamps. (2 of 3)

26 SLIDE 51 Figure 47 Types of clamps. (3 of 3)

27 SLIDE CLAMPS When clamping wood or other soft material, you should use pads or thin blocks of wood between the clamp and the work. Do not apply excessive pressure to a clamp. Clamps with bent frames must be discarded. Figure 48 Placing pads and wood blocks.

28 SLIDE CHAIN FALLS AND COME-ALONGS Chain falls and come-alongs are use to safely move heavy loads. A chain fall is a chain-and-tackle device used to hoist loads. A comealong is used to drag loads. A chain fall has an automatic brake that holds the load after it has been lifted. The brake holds the load until the lowering chain is pulled. Manual chain falls are operated by hand. Some have electric drive motors that are operated from an electrical control box. Figure 49 Parts of a manual chain fall.

29 SLIDE 54A CHAIN FALLS AND COME-ALONGS Come-alongs, also called cable pullers, use a ratcheting handle to move heavy loads horizontally over short distances. They can support up to 6 tons. One end of the come-along is secured to a stationary object; the other end is connected to the object to be moved. Once the connections are made, the ratchet handle is used to take up the chain or cable and move the object. There is also a fast-wind feature for quickly taking up or letting out slack in the chain or cable. Figure 50 Come-alongs.

30 SLIDE 54B A come-along must never be used to lift objects. It does not have the necessary safety features. Some lubrication of a chain fall or come-along may be required. If so, be very careful not to get any lubricant on the clutches. A qualified person must determine if the chain fall or come-along to be used is suitable for the intended purpose.

31 SLIDE SHOVELS Shovels are used for many different purposes on a construction site, such as digging foundation footings and digging trenches for underground wiring and pipe. There are three basic types of shovels: round, square, and spade. A round-blade shovel is used to dig holes and move large amounts of soil. A square-blade shovel is used to move gravel and do cleanup work. A spade is used to move large amounts of soil or to dig trenches that must have smooth, straight sides. Figure 51 Shapes of shovel blades.

32 SLIDE SHOVELS When using a round shovel or spade, push the blade into the soil with your foot. Wear appropriate PPE when shoveling, and keep your shovel clean. Figure 52 Proper use of a shovel.

33 SLIDE PICK A pick is a swinging tool similar to an ax. A pick is typically used to break hardened or rocky soil, chop tree roots, and break up stones and concrete. Long-handled picks are used if a normal amount of swinging force is needed. If more swinging force is needed, use a pick with a shorter handle. The correct way to swing a pick depends on the task. Before using a pick, ensure that the head is firmly attached to the handle, and wear appropriate eye protection. Figure 53 Pick.

34 End of Presentation