Drill America Cobalt Heavy Duty Drill Bit Pack of 6 - Tough Metal

In this review of the Drill America R Cobalt Heavy Duty Drill Bit (Pack of 6) the bottom line is simple: these are jobber length cobalt bits built for users who regularly drill tough, high tensile metals and need longer life than standard HSS. The reviewer found them especially useful for stainless steel, inconel and titanium work where higher red hardness and heat resistance matter. For fabricators, maintenance techs and serious hobbyists who want dependable, sharp bits that hold up under higher speeds, these offer clear performance advantages.

Key Features

• Cobalt steel construction: Provides higher red hardness for improved cutting in high tensile materials, allowing faster speeds and longer life than typical high-speed steel bits.
• Gold oxide surface: A thin oxide finish that protects the flutes without changing cutting performance, offering a balance between corrosion resistance and clean chip evacuation.
• Spiral flutes with right-hand cut: Evacuate chips up and out of the hole to reduce clogging and improve hole quality during continuous drilling.
• Round shank design: Fits a wide range of chucks and toolholding systems, making these bits versatile across drills and drill presses.
• Manufactured to NAS 907: Produced to a National Aerospace standard, indicating consistent geometry and quality for demanding applications.

Who It's For

These drill bits are aimed at professionals and experienced hobbyists who cut through hard, heat-resistant alloys frequently: machinists, metal fabricators, maintenance crews, and those working with PH stainless, inconel or titanium. The pack format and jobber length make them suitable for shop and on-site work where reliable replacement bits are needed.

Those who mostly drill wood, soft metals or occasional household projects may find these heavier-duty bits unnecessary and could save money with standard HSS or coated bits better matched to softer materials.

Pros & Cons

Pros

• Excellent durability and sharpness for cutting hard alloys, leading to longer tool life.
• Allow higher cutting speeds due to heat-resistant cobalt composition.
• Round shanks provide broad compatibility with common chucks and holders.
• Manufactured to a recognized aerospace standard for consistent quality.

Cons

• Gold oxide finish is minimal and offers little additional cutting advantage over uncoated bits.
• Not the ideal economical choice for casual drilling of soft materials.

Specifications

Our Verdict

The Drill America R Cobalt pack is a sensible buy for anyone who regularly drills hard, heat-resistant metals and needs bits that stay sharp and run hotter than HSS. They deliver strong value through durability and consistent manufacturing, but casual users working mostly with soft materials can opt for less expensive HSS options.

Frequently Asked Questions

Are these bits suitable for stainless steel?
Yes, the cobalt construction and higher red hardness make them well suited for stainless and other high tensile alloys.

Will the gold oxide finish affect cutting performance?
The gold oxide is a thin surface treatment for protection; it does not significantly change cutting performance compared with uncoated cobalt bits.

Do these fit common drill chucks?
Yes, the round shank design is compatible with most chucks and standard toolholding systems.