1. Proper drill selection:
   Air drills that turn high RPM’s are not a good choice. Electric drills that are corded or cordless work best because they have a lot of power in lower speeds. Variable speed triggers are a must.

2. Drill Speed:
   Turn bits on a lower RPM → 700-1000 RPM is the best.

3. Know what you are drilling:
   Drilling the steel in the front and in the rear of cars is fairly easy. Once you get near the passenger compartment the metal reinforcements are very hard. Once you drill through the outer sheet metal in these areas and drill into the metal behind the outer sheet, those steels will destroy spot weld bits quickly .

4. Know your spot weld bits:
   All bits have markings on them; this says what they are made of. They will say:

• Hss High Speed Steel – this is made of softer material and will do OK on outer sheet metal, but if you drill into something harder on the other side, it will destroy the bit.
• Hsco High Speed Cobalt – this is a high speed steel with a blend of cobalt. These are much harder than Hss and cut better and last longer.
• Co Cobalt – this is still an Hss bit with a higher blend of Cobalt than Hsco. These are harder than Hsco they cut real well and last a long This bit is a little more brittle than others and may chip on the edge of the flute.

5. Cutting oil:
   Cutting oil is nothing new but is not used much at all by techs. Cutting oil can help with the drilling process and make bits last longer.
   For high quality spot weld bits and cutting oil see your local distributor.

“Save Your Bits”