Professional Cobalt HSS Drill Bits for Stainless Steel & Hard Metals (Pack of 10)

Direct Answer & Overview

This Pack of 10 Cobalt High-Speed Steel (M35 HSS-Co 5%) Drill Bits is designed for extreme-duty metalworking, cutting through tough materials like stainless steel (Inox), high-gauge metal, titanium, cast iron, and high-carbon steel. Manufactured strictly to DIN 338 RN and DIN 1414 industrial standards, each bit features a 135° split-point tip for instant self-centering without skidding. Enhanced with a protective Gold Oxide/Copper ember finish, these bits offer high heat resistance and extended wear life under heavy torque and friction.

Technical Attribute	Specification Details
Product Type	Twist Drill Bits (Pack of 10)
Material Composition	M35 Alloyed High-Speed Steel with 5% Cobalt (HSS-Co 5%)
Manufacturing Standards	Complies with DIN 338 RN & DIN 1414
Surface Finish	Gold Oxide / Copper Ember (High Hardness & Thermal Protection)
Point Angle	135° Self-Centering Split Point
Shank Type	Straight Round Shank
Available Diameters	1.0 mm up to 13.0 mm (Selected Single Size per 10-Pack)
Target Materials	Stainless Steel, High-Carbon Steel, Titanium, Cast Iron, Aluminum
Condition	100% Brand New

Available Sizes & Common Applications

Choose your specific required diameter (10 identical pieces per pack):

Size Range	Available Diameters (mm)	Ideal Applications
Micro / Fine Sizes	1.0mm, 1.5mm, 2.0mm, 2.5mm	Electronics, precise pilot holes, sheet metal rivets
Standard Pilot Sizes	3.0mm, 3.3mm, 3.5mm, 4.0mm, 4.1mm, 4.2mm, 4.5mm	Pop rivets, M3–M5 screw tapping pre-drilling
Mid-Range Joinery	5.0mm, 5.5mm, 6.0mm, 6.5mm, 6.8mm, 7.0mm, 7.5mm	M5–M8 bolt clearance, general steel fabrication
Heavy Mechanical	8.0mm, 8.5mm, 9.0mm, 10.0mm, 10.5mm	M8–M12 structural steel bolts, machinery repairs
Large Bore	11.0mm, 11.5mm, 12.0mm, 12.5mm, 13.0mm	Heavy-duty structural framing, pipe & flange drilling

Key Performance Features

M35 HSS Steel with 5% Cobalt: M35 grade high-speed steel alloyed with 5% cobalt maintains cutting hardness even under high frictional heat that dulls standard HSS bits.
Gold Oxide / Copper Finish: Special thermal surface treatment hardens the exterior body, reduces cutting friction, and resists corrosion over extended store-and-use lifespans.
135° Split Point Tip: Self-centering tip bites immediately into smooth or curved metal surfaces without needing a starter punch, requiring less feed force.
DIN 338 RN & DIN 1414 Certified: Precision-ground to rigorous European standards, ensuring straight drilling tolerances and uniform flute geometry.

Hard Metal Drilling Best Practices

1.Control Drilling RPM:

Always operate power drills or drill presses at lower speeds (RPM) when cutting through stainless steel or hard alloys to prevent extreme heat build-up.

2.Apply Cutting Fluid or Lubricant:

Coat the drill point with cutting oil or lubricant during operation to dissipate friction heat and preserve bit sharpness.

3.Maintain Firm Downward Pressure:

Apply steady, heavy pressure so the bit cuts continuously into the metal rather than riding on top of it, which causes work-hardening.

4.Clear Metal Chips Periodically:

In deep hole drilling, pull the bit back periodically to clear long spiral metal swarf from the flutes.

Frequently Asked Questions (FAQ)

Are these bits suitable for drilling grade 304 and 316 stainless steel?

Yes. M35 alloyed steel with 5% Cobalt content is specifically engineered to cut hard stainless steel grades without losing its edge.

Does a 10-pack contain mixed sizes or 10 bits of one size?

Each pack contains 10 identical drill bits of the single diameter size you select at checkout (e.g., 10x 6.0mm bits).

What does the DIN 338 specification mean?

DIN 338 is an international manufacturing standard that dictates exact dimensions, tolerances, and flute length for right-hand twist drill bits.