STROTON Cobalt Drill Bit Set (1/16-1/2 Inch, 17PCS), M35 High Speed Steel Twist Drill Bits for Stainless Steel, Hard Metal, Cast Iron, Plastic and

STROTON Cobalt Drill Bit Set (1/16-1/2 Inch, 17PCS), M35 High Speed Steel Twist Drill Bits for Stainless Steel, Hard Metal, Cast Iron, Plastic and

Premium 5% Cobalt Steel ,68 HRC (Rockwell Hardness Scale) ,the Cobalt Usually Give the Best Heat,Wear and Chip Resistance and Long Tool Life. The Cutting Edge has been Ground Three Times and is made of Cobalt Steel, which has High Hardness and Heat Resistance. It is Designed for Drilling through Stainless Steel, Hardened Steel, Iron, Aluminum, Pipes, Wood, PVC, and Plastics. This Heavy Duty Work Cobalt Drill Bit is Typically Capable of Running Two to Three Times Faster.Despite the Higher Price,the Cost Per Hole When Using Cobalt Drill Bit Will be the Lowest,Since It Can Produce So Many More Holes. The Sufficiently Sharp Bit Edge Can Cut the Metal Material into Long Strips of Iron Chips rather than Slowly Grinding Through the Material with a Blunt Drill Bit. 17Pcs 135 Degree Cobalt Industrial Hss Drill Bits Kit Includes :1/16 (2pcs), 5/64, 3/32 (2pcs), 7/64, 1/8 (2pcs), 9/64, 5/32, 3/16, 7/32, 1/4 (2pcs), 5/16, 3/8, 1/2 . Product Advantages:

(1) Split Point Desigh tip starts drilling immediately with less force and eliminates "walking" across the work surface.
(2) Holds up better than generic high-speed steel,Cobalt gives high-speed steel more heat and wear resistance.
(3) This drill bits set is made of Premium Cobalt (80,000 dollars per ton).
(4) The 6% cobalt drill bits can cut through Stainless steel and Hard metal,Hard wood, although they can be used for softer materials such as Aluminum,Plastic.

Some Important Tips about drilling stainless steel and hard metal:
    (1)Controling the drill speed from 200 to 1000 RPM would make it easier for you to drill holes on stainless steel.
________________________________
                Stainless Steel                  
    ____________________________
      Drill diameter               RPM        
    ____________________________
      ≤3/16"                       1000~700
    ____________________________
      3/16"-3/8"                     700~350
    ____________________________
      3/8"-1/2"                   350~200
________________________________

    (2)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.