【Premium True 5% Cobalt Steel with 68 HRC】- The Marked Cobalt Content of Ordinary Drill Bits May be False, but This Drill Bits Set is Made of Cobalt Ore from Our Own Mine, Which Indeed Contains 5% Cobalt. Although the Cost and Price are Slightly Higher, It Usually is able to Provide 3X Heat,Wear and Chip Resistance and 3X Tool Life.
【Split Point Design and Fully Ground Process】- Compared with Other Ordinary Drill Bits, This Drill Bits Set is Particularly Suitable for Heavy Duty Work, Such as Cutting through Stainless Steel,Steel Plate,Iron Sheet, Cast Iron and Hardwood, and Drilling Out Bolts Studs and Screws.
【3X Efficiency + 3X Tool Life】- This Cobalt High Speed Steel Drill Bits Set is Typically Capable of Running 3 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.
【Sharp Drill Bit Edge】- This Kind of Drill Bits Beast Can Even Cut Hardened Metal into Long Iron Bars, While a Dull Drill Bit Can Just Slowly Wear Through Metal.
【13 Pieces Jobber Length Industrial Drill Bits Includes】:1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 11/64, 3/16, 13/64, 7/32, 15/64, 1/4 [DIA 1/64 Inch Increments]

Product description

Why Choose Premium STROTON Cobalt Drill Bits?

Researches have shown that compared with HSS without cobalt, HSS with cobalt has higher temperature resistance, red hardness, wear resistance and heat treatment response.

Red hardness, which means that the drill bits hardened steel can maintain hard at 860-880℃.
68 HRC,it means that the drill bits has 3X cutting ability and 3X durability.
This drill bits set is made of True Premium Cobalt (80,000 dollars per ton).

Truly Made of 5% Cobalt Alloy Steel

This drill bits set definitely have more cobalt in them than the "Cobalt" bits that HF sells--which are just Cobalt coated or only a tiny amount of cobalt tipped.
Compared with ordinary high speed steel, 5% cobalt provides better heat and wear resistance,and Hold up Better.

3X Drilling Efficiency + 3X Tool Life

Split Point desigh tip starts drilling immediately with less force and eliminates "walking" across the work surface.
Ideal for Stainless steel,Mild Steel,Iron,Hardmetal,Aluminum,Copper,Plastic and Hardwood.
The drill bit can be used for mechanical maintenance, such as drilling out bolts and screws.

Be vertical to the workpiece

Non-vertical use may cause the drill bit to break.
Using a drill press with sufficient power will make drilling easier.

Low speed: 200 to 1000 RPM

Too high speed may burn the bit tip.
Drill diameter≤3/16，RPM（1000~700）
3/16-3/8，RPM（700~350）
3/8-1/2，RPM（350~200）

Use cutting fluid

Add stainless steel tapping oil or engine oil to prevent the stainless steel from overheating.
It also works adding some vinegar,soy sauce or water.

Remain steady and patient

The drilling shall be started slowly by applying force slowly and gently until the drill bit starts chipping.