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

In this review of the Drill America P Cobalt Heavy Duty Drill Bit pack of 6, the bottom line is simple: these are worksite-ready jobber length bits built for cutting hard metals where standard high-speed steel fails. The reviewer recommends them for fabricators, machinists, and maintenance pros who need reliable cobalt performance and longer tool life when tackling stainless steel, inconel, or titanium. The single biggest reason to buy is the cobalt construction that lets these bits run hotter and last noticeably longer on tough alloys compared with typical HSS bits.

Key Features

• Cobalt steel construction: Provides higher red hardness so the bits handle elevated cutting temperatures and last longer in hard alloys.
• Gold oxide finish: A thin oxide surface aids identification without changing cutting performance significantly compared with uncoated bits.
• Round shanks: Work with a wide variety of chucks, collets, and drill presses for easy toolholding on the shop floor.
• Right-hand spiral flute: Evacuates chips up and out of the hole to reduce clogging when drilling deep or gummy materials.
• Manufactured to NAS 907: Produced to an aerospace-related standard, indicating consistent geometry and quality for critical applications.

Who It's For

The pack is best for professional tradespeople and serious hobbyists who regularly drill stainless steel, nickel alloys, or other high tensile materials and need a cost-effective cobalt option. Its jobber length and robust cutting edge make it useful for metalworking shops, maintenance crews, and DIYers tackling corrosion-resistant fastener removal or fabrication projects.

Those who primarily drill soft materials like wood or plastics, or who require metric sizes, may prefer less expensive HSS bits or a different specialty set; this pack is targeted at tougher metal work where the cobalt advantage matters.

Pros & Cons

Pros

• Durable cutting life on hard metals thanks to cobalt steel that sustains higher speeds.
• Consistent performance and sharp initial edges produce clean holes with less walking.
• Round shanks and standard jobber length make the bits broadly compatible with common toolholders.

Cons

• The gold oxide is primarily identification rather than a performance coating, so users wanting advanced lubricious coatings should look elsewhere.

Specifications

Brand	Drill America
Series	D/ACO
Material	Cobalt steel (heat resistant)
Finish	Gold oxide thin surface treatment
Shank type	Round shank
Length	Jobber length
Manufacturing standard	National Aerospace standard 907

Our Verdict

These Drill America cobalt jobber bits are a practical choice for anyone who needs dependable drilling in stainless and other high-strength alloys; they deliver greater heat resistance and longer life than standard HSS at a competitive price. For metalworkers seeking solid performance without specialty coatings, this pack represents strong value and consistent results on tough materials.

Frequently Asked Questions

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

Will the gold oxide coating improve cutting life?
The gold oxide is a thin identification finish and does not significantly change cutting life compared with uncoated cobalt; the cobalt alloy itself provides the durability.

Do these bits fit common chucks?
Yes, the round shanks are compatible with standard drill chucks and many collet systems used on shop drills.