Cobalt Heavy Duty Drill Bit Pack of 12 - Jobber Length Performance

In this review the Drill America A Cobalt Heavy Duty Drill Bit pack is evaluated for metalworkers and serious DIYers who need durable bits for tough alloys. The bottom line: these jobber length cobalt drills are best for drilling stainless steel, nickel alloys and other high tensile materials where standard high-speed steel bits struggle. The reviewer found the set offers sharp, long-lasting cutting performance and heat resistance that lets users run higher speeds and maintain cleaner holes under heavy use.

Key Features

• Cobalt construction: The higher cobalt content raises red hardness, allowing drills to hold cutting edges longer when working stainless steel, inconel and titanium.
• Gold oxide finish: A thin gold oxide surface treatment helps identify the bits and provides similar performance to uncoated tools while resisting minor corrosion.
• Round shanks: Standard round shanks fit a wide variety of chucks and toolholding systems for flexibility in bench and portable drills.
• Right-hand spiral flute: When run clockwise the spiral flutes evacuate chips up and out of the cut to reduce clogging during deep or continuous drilling.
• Manufactured to NAS 907: Produced to National Aerospace standard 907 for consistent geometry and reliable performance in demanding applications.

Who It's For

The set is aimed at machinists, fabricators and hobbyists who regularly drill hard, high tensile metals and need tools that last longer than typical HSS bits. If you work with stainless steel, PH stainless, inconel or titanium, the cobalt composition and higher red hardness are practical advantages.

Users who only drill soft metals occasionally or want coated titanium nitride for reduced friction on softer materials might find these overkill. Also, those needing specialized shank types like hex or reduced-width should look for alternate sets tailored to their chucks.

Pros & Cons

Pros

• Excellent durability and edge retention compared with standard HSS bits, reducing replacement frequency.
• Performs well on stainless and other tough alloys at higher cutting speeds due to heat-resistant cobalt.
• Round shanks and common jobber length make the set versatile for many drills and applications.
• Manufacture to NAS 907 gives consistent geometry and reliable drill performance.

Cons

• Gold oxide is a thin treatment and offers similar performance to uncoated tools, so users expecting a thick wear coating may be disappointed.
• Angle feedback from some users is mixed, suggesting care is needed to maintain the correct drilling angle for best results.

Specifications

Our Verdict

The Drill America cobalt jobber set is a solid, value-oriented choice for anyone who needs dependable drill performance in hard metals. Its heat-resistant cobalt composition and consistent manufacture to NAS 907 make it a practical upgrade over HSS bits for stainless, inconel and similar alloys, offering good longevity and clean cuts for a reasonable price.

Frequently Asked Questions

Are these suitable for stainless steel?
Yes. The cobalt composition and higher red hardness make them well suited to drilling stainless and other high tensile materials.

Do the bits come coated with TiN?
No. They have a thin gold oxide surface treatment which is not the same as a thick TiN wear coating but helps with identification and minor corrosion resistance.

Will the round shanks fit standard chucks?
Yes. The round shanks are compatible with most drill chucks and common toolholding systems.