Hertel 4140430 Cobalt Jobber Drill Bit No. 51 Wire

Product Description

The HERTEL 4140430 is a cobalt jobber-length drill bit designed for heavy-duty holemaking in hard and abrasive materials. It carries a No. 51 wire gauge size, corresponding to a decimal diameter of 0.0670 inches, and features a 135-degree split-point geometry for fast self-centering starts without a center punch. A TiAlN (titanium aluminum nitride) coating extends tool life by resisting heat buildup at high cutting speeds. Overall length is 2 inches with a 1-inch flute length. This is a right-hand cutting tool suited for use in drill presses, CNC machining centers, and handheld power drills on production or maintenance applications.

This bit is rated for holemaking in stainless steel, high-temperature alloys, cast iron, and other hard ferrous materials where standard high-speed steel bits wear prematurely. The heavy-duty cobalt grade makes it a common choice in industrial maintenance, fabrication shops, and mechanical contracting work where long run times and material hardness demand a more heat-resistant substrate. The consistent 0.0670-inch shank diameter matches the drill diameter for straightforward chuck mounting.

Key Features

• No. 51 wire size — 0.0670 inch decimal diameter for precision small-bore holemaking
• 135-degree split point reduces thrust and eliminates walking on entry
• Cobalt construction provides superior heat and wear resistance versus standard HSS
• TiAlN coating adds a thermal barrier for extended tool life at higher feed rates
• Right-hand cutting, jobber-length series for general-purpose depth-to-diameter ratio
• Heavy-duty grade rated for hard ferrous and high-temperature alloy applications

Compatibility

Designed as a jobber-length drill bit for use in any standard drill press, CNC machining center, or handheld power tool with a chuck capable of accepting a 0.0670-inch shank diameter.

Installation Notes

Install and remove drill bits only with the machine fully powered down and the spindle at a complete stop. Secure the shank firmly in the chuck and verify concentricity before beginning a cut to avoid deflection on small-diameter bits. Use appropriate cutting fluid or coolant when drilling stainless steel or high-temperature alloys to maximize tool life; note that this bit does not support coolant-through operation. Follow applicable OSHA machine-guarding requirements and shop safety protocols when operating drilling equipment.