Drill America 15/16ft Reduced Shank Cobalt Drill Bit - Tough Metal

In this review the Drill America 15/16' Reduced Shank Cobalt Drill Bit with 1/2' shank is assessed for metalworkers who need a larger diameter bit that fits standard portable chucks. The bottom line: this bit is best for users who must drill tougher alloys and want a reduced shank to expand chuck capacity; its heat resistant cobalt construction and precision ground geometry are the single biggest reasons to buy. Performance varies by use, but the bit's design targets durability and concentricity in demanding drilling tasks.

Key Features

• Cobalt steel construction: provides improved wear resistance and heat tolerance for drilling harder metals such as stainless steel and nickel alloys.
• Reduced 1/2' shank: lets a 15/16' cutting diameter be used in common portable drill chucks, expanding size range without special adaptors.
• 135 degree split point: minimizes walking and helps the bit start on center for cleaner, more accurate holes without pre-drilling pilot marks.
• Precision ground concentricity: ensures a close alignment between shank and body that reduces runout and improves hole accuracy in press or hand drills.
• Spiral flutes, right-hand cut: evacuate chips up and out of the hole to reduce clogging during continuous cuts.
• Gold oxide surface treatment: provides a thin protective layer without changing cutting performance, similar to an uncoated tool while offering corrosion resistance in storage.

Who It's For

The bit suits machinists, maintenance technicians, and serious DIYers who frequently drill medium to high tensile strength metals and need a large diameter that will fit standard drill chucks. It is particularly useful when a press or portable drill must handle a 15/16' hole without special tooling.

Those who should look elsewhere include users needing extreme toughness for heavy production runs where carbide tooling is more appropriate, or buyers seeking consistently flawless cutting edge retention at very high feed rates; some users report mixed results on sharpness and breakage under abusive use.

Pros & Cons

Pros

• High heat resistance from cobalt steel helps retain hardness when cutting hot metals.
• Reduced 1/2' shank expands compatibility with standard drill chucks and portable tools.
• Precision ground and 135 split point reduce walking and improve hole accuracy.
• Gold oxide finish protects the surface without changing cutting feel.

Cons

• Mixed user reports on durability and sharpness mean results can vary with technique and material; some buyers found early dulling or breakage.
• Not coated for extreme wear resistance like TiN or TiAlN, so performance may be closer to uncoated tools in heavy production use.

Specifications

Brand	Drill America
Cutting diameter	15/16'
Shank diameter	1/2'
Material	Cobalt steel
Point angle	135 degree split point
Finish	Gold oxide
Standards	Manufactured to National Aerospace standard 907

Our Verdict

The Drill America 15/16' reduced shank cobalt bit is a practical choice for tradespeople who need a large diameter drill that fits standard chucks and holds up to tougher metals. It offers good value due to its heat resistant cobalt composition and precision grinding, though users should follow proper feeds, speeds, and pecking cycles to avoid the mixed durability issues reported by some buyers.

Frequently Asked Questions

Can this bit be used in a portable drill?
Yes, the 1/2' reduced shank is sized to fit most portable drill chucks so you can use a 15/16' cutting diameter without special adapters.

Is this suitable for stainless steel?
Yes, the cobalt steel construction is intended for harder metals like stainless steel and nickel alloys, giving better heat resistance than typical HSS.

Does the gold oxide change cutting performance?
No, the gold oxide is a thin surface treatment that mainly offers corrosion protection and does not significantly alter cutting behavior compared with uncoated tools.