Drill America B Cobalt Heavy Duty Drill Bit Pack of 12 - Durable Cuts

In this review the Drill America B Cobalt Heavy Duty Drill Bit pack of 12 is evaluated for machinists and metalworkers who need a dependable set of jobber length bits for tough alloys. The bottom line: these bits are built of heat resistant cobalt that maintains cutting edge and higher red hardness for longer life, making them a practical choice when drilling stainless steel, inconel and other high tensile materials. The review focuses on real-world durability, cutting performance and value for money based on customer feedback and product features.

Key Features

• Cobalt steel construction: Provides higher red hardness so bits can be run at higher speeds and cut tougher metals without rapid wear.
• Gold oxide finish: A thin oxide surface treatment helps identify the tool and has similar performance to uncoated bits while resisting light surface corrosion.
• Round shank: Fits a wide variety of toolholding systems for easy use across drills and chucks without specialized holders.
• Right-hand spiral flutes: Evacuate chips up and out of the cut when run counterclockwise, reducing clogging in deep holes.
• Manufactured to NAS 907: Built to a National Aerospace standard that signals consistent geometry and quality for demanding applications.

Who It's For

These bits are aimed at professional tradespeople, fabricators and hobbyists who frequently drill high tensile materials like PH stainless, nickel alloys, inconel and titanium and need tools that last longer than standard high-speed steel. The pack format suits shops that consume bits regularly and want consistent replacements without buying singles.

Those who primarily drill soft materials such as wood or nonferrous metals with a consumer cordless driver may find this set overkill; softer-material users can choose standard HSS bits that are less costly and more appropriate for low-stress work.

Pros & Cons

Pros

• Excellent durability: customers report noticeably longer life compared with some competing cobalt bits.
• Strong cutting performance on tough alloys thanks to heat-resistant cobalt material.
• Versatile fit: round shanks work with common chucks and holders, simplifying use in shop environments.

Cons

• Gold oxide is a very thin finish and offers similar performance to uncoated tools, so users expecting a durable coating may be disappointed.
• Angle feedback is mixed among buyers, so accuracy of edge geometry may vary slightly between pieces.

Specifications

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

Our Verdict

The Drill America B cobalt jobber set is a solid value for anyone needing reliable performance on stainless and high-strength alloys; its heat resistant cobalt construction and NAS 907 manufacture make it a practical purchase for shops that need longer-lasting bits. Buy this pack if you drill tough metals regularly and want consistent, durable cutters without premium coatings.

Frequently Asked Questions

Are these bits good for stainless steel?
Yes. The heat resistant cobalt and higher red hardness make them suitable for drilling stainless and other high tensile materials.

Do the bits come coated for extra wear resistance?
They have a thin gold oxide surface treatment that mainly identifies the cobalt grade; performance is similar to uncoated tools.

Will the round shanks fit standard chucks?
Yes. The round shank design allows use with a wide variety of common toolholding systems and chucks.