63/64 in Reduced Shank Cobalt Drill Bit - Durable Metal Drilling

In this review the 63/64 in Reduced Shank Cobalt Drill Bit with 1/2 in shank is assessed as a focused tool for tradespeople who need a bit that can tackle tougher ferrous metals while fitting smaller chucks. The bottom line: it works best when used in a drill press or a steady portable drill for intermittent heavy work because the cobalt steel construction resists heat and holds form in stainless and nickel alloys, but variable user reports on sharpness and breakage mean it is not a universal choice for high-volume production without careful technique.

Key Features

• Cobalt steel: Increased cobalt content improves red hardness so the bit maintains cutting edge when drilling high tensile metals like stainless steel and nickel alloys.
• Reduced shank: The 63/64 in diameter body with a 1/2 in shank expands the size range of portable drill chucks without sacrificing the ability to cut larger holes.
• 135 split point: Precision ground heavy duty 135 split point starts on contact and reduces walking for more accurate hole placement.
• Spiral flutes: Right-hand spiral flutes evacuate chips up and out of the hole to reduce clogging and keep cutting efficient.
• Precision ground concentricity: Ground to a high degree of alignment between shank and body for stable running in chucks and holders.
• National Aerospace standard: Manufactured to NAS 907 which informs consistent dimensions and tolerances for critical work.

Who It's For

This bit is aimed at mechanics, fabricators, and serious hobbyists who need a single larger-diameter drill that fits into a 1/2 in chuck but drills like a 63/64 in bit into tougher metals. It suits intermittent shop use where the operator can control feed rate and cooling. The heat resistant cobalt alloy is particularly useful when drilling stainless parts or other higher tensile materials.

Those who should look elsewhere include high-volume production shops that need consistent failure-free performance on every hole without re-sharpening, and users who require a coated finish for extended life in abrasive conditions, since gold oxide here is a thin treatment and performs similarly to uncoated bits.

Pros & Cons

Pros

• Good hardness retention for drilling stainless and other tough alloys thanks to the cobalt content.
• Reduced shank design allows use in common 1/2 in chucks so larger holes can be drilled with standard portable tools.
• 135 split point and precision grind improve bite and concentricity for cleaner holes when set up correctly.
• Manufactured to a National Aerospace standard, offering consistent dimensions for replacement and interchangeability.

Cons

• Customer reports indicate mixed sharpness and occasional breakage, so technique, proper speed, and coolant are important to avoid failure.
• Gold oxide is a thin surface treatment that provides limited additional wear resistance compared with thicker coatings.

Specifications

Diameter	63/64 in
Shank	1/2 in round
Material	Cobalt steel (heat resistant)
Point style	135 split point
Flute	Right-hand spiral
Finish	Gold oxide (thin)
Standard	Manufactured to NAS 907

Our Verdict

The 63/64 in Reduced Shank Cobalt Drill Bit is a practical, value-minded choice for tradespeople and serious DIYers who need to drill larger holes in tougher metals with a 1/2 in chuck. It delivers heat resistance and good starting behavior from the split point, but buyers should plan for controlled drilling speeds, use of coolant, and inspection of sharpness to avoid the mixed durability reports.

Frequently Asked Questions

Can this bit drill stainless steel?
Yes, the cobalt alloy and 135 split point make it suitable for stainless steel when used at appropriate speeds with cutting fluid.

Will it fit a standard 1/2 in portable drill?
Yes, the reduced shank is 1/2 in round so it fits common 1/2 in chucks and expands usable diameter range.

Is the gold oxide coating a hard protective layer?
No, the gold oxide on this bit is a thin surface treatment that mainly identifies cobalt tools and does not provide substantial extra wear resistance compared with thicker coatings.