M35 5% Cobalt Metric Drill Bits Set (1mm-10mm/19pcs), Straight Shank Jobber Drill Bits, Metal HSS Twist Drill Bits for Stainless Steel Hard Metal and Cast Iron

Description

Suitable for drilling Stainless Steel,Hard Metals,Aluminum,Copper,Plastic and Hardwood. The 3 steps design makes it accurately centered for woodworking jobs that require precision drilling. Also, the cobalt-containing design makes it perform even better in hardwood drilling. Controling the drill speed from 200 to 1000 RPM would make it easier for you to drill holes on stainless steel. A high RPM does not improve drilling efficiency, but rather increases the heat between the bit and the workpiece, which may cause the bit to soften and the workpiece to harden. Drill diameter≤5mm，RPM（1000~700） 5-10mm，RPM（700~350） 10-15mm，RPM（350~200） Using cutting fluid will make the bit last longer. Add stainless steel tapping oil or engine oil to prevent the stainless steel from overheating and forming a very hard oxide layer. It also works adding some vinegar,soy sauce or water if you don't have engine oil.