SAFETY RULES FOR WRENCHES

bars of tool steel (fig. 1-41). They generally range in size up to 3/4 inch. When using the Allen-type wrench, make sure you use the correct size to prevent rounding or spreading the head of the screw. A snug fit within the recessed head of the screw is an indication that you have the correct size. The Bristol wrench is made from round stock. It is also L-shaped, but one end is fluted to fit the flutes or little splines in the Bristol setscrew (fig. 1-41). SAFETY RULES FOR WRENCHES There are a few basic rules that you should keep in mind when using wrenches. They are as follows: � Always use a wrench that fits the nut properly. � Keep wrenches clean and free from oil. Otherwise they may slip, resulting in possible serious injury to you or damage to the work. � Do not increase the leverage of a wrench by placing a pipe over the handle. Increased leverage may damage the wrench or the work. � Provide some sort of kit or case for all wrenches. Return them to the case at the completion of each job. This saves time and trouble and aids selection of tools for the next job. Most important, it eliminates the possibility of leaving them where they can cause injury to personnel or damage to equipment. � Determine which way a nut should be turned before trying to loosen it. Most nuts are turned counterclockwise for removal. This may seem obvious, but even experienced people have been observed straining at the wrench in the tightening direction when they wanted to loosen the nut. � Learn to select your wrenches to fit the type of work you are doing. If you are not familiar with these wrenches, make arrangements to visit a shop that has most of them, and get acquainted. REVIEW QUESTIONS Q11. Identify the different types of wrenches. Q12. Describe the uses of different types of wrenches. Q13. List the safety precautions that apply to wrenches. PLIERS LEARNING OBJECTIVES: Identify the different types of pliers. Describe the uses of different types of pliers. Describe the proper care of pliers. Pliers are made in many styles and sizes and are used to perform many different operations. Pliers are used for cutting purposes, as well as holding and gripping small articles in situations where it may be inconvenient or impossible to use hands. Figure 1-42 shows several different kinds. 1-27 Figure 1-41.—Allen- and Bristol-type wrenches. Figure 1-42.—Pliers.