Chapter 11 Sawing and Cutoff Machines 159 Copyright Goodheart-Willcox Co., Inc. T he first step in most machining jobs is to cut the stock to the required length. This can be done using power saws, Figure 11-1. 11.1 Metal-Cutting Power Saws There are three principal types of metal-cutting power saws, Figure 11-2. Reciprocating saws (power hacksaws) use a back-and-forth (reciprocating) cutting action. The cutting is done on the backstroke. The blade is similar to that of a handheld hacksaw, but it is larger and heavier. Band saws have a continuous blade that moves in one direction. Circu- lar saws have a round, flat blade that rotates into the work. A toothed blade, friction blade, or abrasive blade may be used, depending on the material and the operation. alterfalter/Shutterstock.com Figure 11-1. The fi rst step in most machining jobs is to cut the stock to the desired length. Measure the cutoff length carefully and observe all safety precautions. Lifts slightly on forward noncutting stroke Abrasive cutoff wheel, circular toothed blade, or circular no-tooth blade (friction cutting) Cuts only on this stroke Reciprocating saw Continuous cutting Circular saw Band saw Goodheart-Willcox Publisher Figure 11-2. The three principal types of metal-cutting power saws.