Dewalt DCS391M1 Instruction Manual - Page 16

English Blade DW9155 DW9154 DW9153 Diameter 6-1/2" (165 mm) 6-1/2" (165 mm) 6-1/2" (165 mm) Teeth 18 24 90 Application General purpose cutting Smooth wood cutting Non-carbide, plywood/ vinyl siding cutting If you need assistance regarding blades, please call 1-800-4-DEWALT (1-800-433-9258). KICKBACK Kickback is a sudden reaction to a pinched, bound or misaligned saw blade, causing an uncontrolled saw to lift up and out of the workpiece toward the operator. When the blade is pinched or bound tightly by the kerf closing down, the blade stalls and the motor reaction drives the unit rapidly back toward the operator. If the blade becomes twisted or misaligned in the cut, the teeth at the back edge of the blade can dig into the top surface of the wood causing the blade to climb out of the kerf and jump back toward the operator. Kickback is more likely to occur when any of the following conditions exists. 1. IMPROPER WORKPIECE SUPPORT A. Sagging or improper lifting of the cut off piece can cause pinching of the blade and lead to kickback (Fig. 12). B. Cutting through material supported at the outer ends only can cause kickback. As the material weakens it sags, closing down the kerf and pinching the blade (Fig. 12). C. Cutting off a cantilevered or overhanging piece of material from the bottom up in a vertical direction can cause kickback. The falling cut off piece can pinch the blade. D. Cutting off long narrow strips (as in ripping) can cause kickback. The cut off strip can sag or twist closing the kerf and pinching the blade. E. Snagging the lower guard on a surface below the material being cut momentarily reduces operator control. The saw can lift partially out of the cut increasing the chance of blade twist. 2. IMPROPER DEPTH OF CUT SETTING ON SAW To make the most efficient cut, the blade should protrude only far enough to expose one-half of a tooth as shown in Figure 7. This allows the shoe to support the blade and minimizes twisting and pinching in the material. See the section titled Cutting Depth Adjustment. 3. BLADE TWISTING (MISALIGNMENT IN CUT) A. Pushing harder to cut through a knot, a nail, or a hard grain area can cause the blade to twist. B. Trying to turn the saw in the cut (trying to get back on the marked line) can cause blade twist. C. Overreaching or operating the saw with poor body control (out of balance), can result in twisting the blade. D. Changing hand grip or body position while cutting can result in blade twist. E. Backing up the saw to clear blade can lead to twist. 4. MATERIALS THAT REQUIRE EXTRA ATTENTION A. Wet lumber B. Green lumber (material freshly cut or not kiln dried) C. Pressure treated lumber (material treated with preservatives or anti-rot chemicals) 5. USE OF DULL OR DIRTY BLADES Dull blades cause increased loading of the saw. To compensate, an operator will usually push harder which further loads the unit and promotes twisting of the blade in the kerf. Worn blades may also have insufficient body clearance which increases the chance of binding and increased loading. 14