Bosch 11239VS Operating Instructions - Page 8

BM 1619929510 2/03 2/12/03 12:23 PM Page 8 release button, slide the depth gauge to desired depth and release pressure on button to lock the depth gauge in place. TOOL TIPS Following a few simple tips will reduce wear on the tool and the chance of injury to the operator. The high efficiency available from the BOSCH Rotary Hammer can only be obtained if sharp and undamaged drilling tools are used. Note that the costs for maintaining sharp drilling tools are more than offset by the time lost in operating dull drilling tools. All grease packed hammers require a short time to warm up. Depending on the temperature, this time will vary from approximately 15 seconds (90° F) to 2 minutes (32° F). The tool will exert its full power and hammering action after the heat from impact hammering has spread, softening the grease. CARBIDE TIPPED BITS Used for drilling stone, concrete, cement, brick, cinder block and other unusually hard non-metals. The Rotary Hammer is designed for "SDS" Carbide Tipped Bits up to 3/4 inch diameter. 3 JAW CHUCK The 3 Jaw Chuck with SDS Shank Adaptor accessory can convert your tool for use with straight shank bits. You will extend the life of your bits and do neater work if you always put the bit in contact with the workpiece BEFORE pulling the trigger. During operation, hold the drill firmly and exert moderate, steady pressure. Too much pressure at low speed will stall the hammer. Too little pressure will keep the bit from cutting and cause excess friction by sliding over the surface. This can be damaging to the drill and bit. Shanks of all drill bits should be wiped clean prior to using and immediately after removing. RECALL THESE INSTRUCTIONS FOR SAFE OPERATION: 1. Some materials require slow drilling speeds; whereas, others require higher speed to produce the best results. 2. All work must be supported or secured before drilling and steady, even pressure applied in line with the drill bit. 3. As the drill bit cuts through the opposite side, reduce the pressure and continue running the drill as the bit is withdrawn. Materials such as glass, porcelain, ceramics, tiles, plastics, etc., should be drilled at low speeds with specially designed drill bits and lubricants. DRILLING WOOD OR PLASTIC If backing block is not used, ease up on the pressure just before the bit breaks through the wood to avoid splintering. Complete the hole from the opposite side immediately after the point breaks through. If bit binds, reverse the drilling operation to help remove the bit from the work. DRILLING METAL Make a center punch in the material for easier starting. Use enough pressure to keep the bit cutting. If the bit is allowed to merely spin in the hole, it will become dull within a short time. When drilling a larger hole, it is faster and easier on your power pack to first make a smaller hole and enlarge it to the required size. Lubricate the tip of the bit occasionally with CUTTING OIL for easier metal drilling. If bit binds, reverse the drilling to help remove the bit from the work. DRILLING MASONRY Use carbide-tipped masonry bit for cinder block, mortar, common brick, soft stone and other materials. The amount of pressure to be used is dependent upon the type of material being drilled. Soft materials require less pressure while the hard materials need more pressure to prevent the drill bit from spinning. -8-