HSS-Co M35 5% Cobalt Jobber Twist Drill Bit Sets (5, 10, 19, or 25-Piece Options)

Direct Answer & Overview

These M35 HSS 5% Cobalt Jobber Twist Drill Bit Sets are industrial-grade metalworking kits engineered specifically for drilling tough materials, including stainless steel (Inox), cast iron, titanium, and high-tensile alloys. Manufactured to DIN 338 standards and fully ground from solid M35 high-speed steel enriched with 5% cobalt, these bits provide extreme thermal resistance and structural durability. Bits 3mm and larger feature a 135° split-point self-centering tip to prevent bit walking without a center punch. Available in four selectable set configurations (5, 10, 19, or 25 pieces).

Technical Attribute	Specification Details
Product Type	Jobber Length Twist Drill Bit Sets
Available Set Options	5-Piece, 10-Piece, 19-Piece, or 25-Piece Sets
Material Grade	M35 High-Speed Steel with 5% Cobalt (HSS-Co 5%)
Manufacturing Standard	DIN 338 Fully Ground from Solid Material
Point Angle	135° Self-Centering Split Point (3mm & above)
Size Range Covered	1.0 mm up to 13.0 mm (Depending on Set Selected)
Primary Suitability	Stainless Steel, Cast Iron, Alloy Metals, Wood, Plastics
Storage (19 & 25 Sets)	Heavy-Duty Indexing All-Metal Storage Case
Condition	100% Brand New

Selectable Set Options & Size Breakdown

Set Option	Piece Count	Included Diameters (mm)	Packaging / Case	Ideal Application
4–10mm Set	5 Pieces	4.0, 5.0, 6.0, 8.0, 10.0	Standard Pack	General DIY & basic home metal repairs
1–10mm Set	10 Pieces	1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0	Standard Pack	Complete whole-millimeter workshop set
1–10mm Set	19 Pieces	1.0 to 10.0 mm in 0.5mm increments	Heavy-Duty Metal Case	Precision tap drilling & fabrication
1–13mm Set	25 Pieces	1.0 to 13.0 mm in 0.5mm increments	Heavy-Duty Metal Case	Master engineering & structural metalwork

Key Performance Features

M35 Cobalt Alloy Construction: 5% Cobalt blend maintains cutting hardness under high friction heat that dulls standard high-speed steel bits.
135° Split Point Tip (≥3mm): Self-centers immediately upon contact with smooth or curved metal surfaces, preventing skidding without needing a center punch.
DIN 338 Fully Ground Flutes: Precision-ground from solid stock for exact dimensional accuracy, smooth chip clearance, and straight hole alignment.
Metal Case Organization (19pc & 25pc Sets): Sturdy metal index boxes keep bits organized by size for quick identification on job sites.

Stainless Steel & Metal Drilling Best Practices

1.Control RPM Speed:

Operate power drills or drill presses at lower RPMs when drilling stainless steel or hard alloys. High speeds generate excessive heat that destroys cutting edges.

2.Apply Cutting Fluid:

Always lubricate the drill bit tip with cutting fluid or oil during operation to reduce friction and extend tool life.

3.Maintain Steady Pressure:

Apply firm, constant downward pressure so the bit cuts continuously rather than riding on top of the metal, which causes work-hardening.

4.Clear Metal Swarf:

Periodically retract the bit when drilling deep holes to clear spiral metal shavings from the flutes.

Frequently Asked Questions (FAQ)

What is the difference between the 10-piece and 19-piece 1–10mm sets?

The 10-piece set includes whole-millimeter increments only (1, 2, 3... 10mm). The 19-piece set includes 0.5mm step increments (e.g., 1.5mm, 2.5mm) and comes with a protective metal storage case.

Do all bits in these sets feature a 135° split point tip?

Bits sized 3.0mm and above feature the 135° split point tip. Smaller bits under 3.0mm feature standard point geometry due to structural thinness.

Are M35 5% Cobalt bits suitable for drilling stainless steel?

Yes. M35 cobalt steel is specifically designed for drilling hard metals like grade 304 and 316 stainless steel, cast iron, and titanium alloys.