What It Is

The Drill America M42 Cobalt Jobber Length Drill Bit is manufactured from premium M42 high speed steel alloy containing approximately 8% cobalt. This increased cobalt content significantly enhances hardness, wear resistance, and heat tolerance compared to both M2 and M35 drill bits.

M42 is commonly selected for demanding metalworking environments where edge retention and durability are critical.

Why M42 Cobalt?

M42 cobalt steel enhances red hardness - the ability of a cutting tool to maintain hardness at elevated temperatures.

Compared to M35 (5% cobalt):

• Higher hardness levels
• Greater wear resistance
• Improved performance in hardened steel
• Better suited for production drilling
• Longer edge life under heavy load

This makes M42 ideal for professional and industrial applications requiring consistent performance in tough materials.

135° Split Point Performance

The precision 135° split point geometry starts drilling immediately on contact and reduces walking. Sizes smaller than 1/16 have the 118 degree standard point.

The flatter 135° angle is especially effective in harder metals where a standard 118° point may wander.

Applications

The Drill America M42 cobalt drill bit is well suited for:

• Hardened steel
• Stainless steel
• Tool steel
• Titanium
• Inconel
• Alloy steel
• Cast iron

Jobber Length Versatility

Jobber length is the most commonly used drill bit length in industrial applications. It offers:

• Sufficient flute length for general drilling depths
• Improved rigidity compared to longer bits
• Reduced deflection
• Broad compatibility across drilling equipment

Compatible with drill presses, handheld drills, and light machining applications.

Frequently Asked Questions

What is M42 cobalt steel?

M42 is a high speed steel alloy containing approximately 8% cobalt. The added cobalt increases hardness and heat resistance compared to standard M2 high speed steel.

How is M42 different from M2?

M42 contains cobalt, which improves red hardness and wear resistance. This allows it to perform better in stainless steel and high tensile strength materials.

What is the difference between M35 and M42 cobalt?

M42 contains approximately 8% cobalt and offers higher hardness and heat resistance than M35. M35 is ideal for general tough metal drilling, while M42 is suited for heavy-duty and high-production applications.

What does “split point” mean?

A split point drill bit features a 135° tip geometry that starts drilling on contact and reduces walking compared to standard 118° drill bits.

What materials can this drill bit drill?

This bit is designed for stainless steel, Inconel, titanium, alloy steel, cast iron, and other high tensile strength materials.

Can this drill bit be used in a hand drill?

Yes. The round shank design is compatible with drill presses, handheld drills, and standard chucks.