Drill America L Cobalt Heavy Duty Drill Bit Pack of 12 - Durable

In this review the Drill America L Cobalt Heavy Duty Drill Bit pack of 12 is evaluated for metalworkers and serious DIYers who need longer life when drilling hard alloys. The bottom line: this jobber-length set stands out for cutting tougher metals because the cobalt construction improves heat resistance and red hardness, allowing faster speeds and longer life than typical high-speed steel bits. For anyone chasing clean, sharp holes in stainless, inconel or titanium, the performance boost is the single biggest reason to buy.

Key Features

• Cobalt steel construction: Provides higher heat resistance and red hardness so bits cut harder alloys with less wear.
• Gold oxide finish: A thin oxide surface treatment that identifies the tool and offers corrosion resistance similar to uncoated bits while preserving sharpness.
• Round shanks: Allow compatibility with a wide variety of chucks and toolholding systems for flexible use in bench and hand drills.
• Spiral flute design: Right-hand spiral flutes evacuate chips up and out of the hole to reduce clogging and keep cuts cleaner.
• Manufactured to NAS 907: Built to a National Aerospace standard, implying consistent dimensions and quality for professional use.

Who It's For

The set is best for machinists, metal fabricators and experienced hobbyists who regularly drill high tensile materials like PH stainless steel, titanium or nickel alloys and need bits that tolerate higher speeds and tougher conditions. It suits users who want longer life and sharper performance than typical HSS bits.

Less suitable are casual users who only drill soft materials or those who prioritize the lowest upfront cost; for light occasional work a basic HSS set may be more economical. Also, anyone requiring non-round shanks for specialized collets should check compatibility first.

Pros & Cons

Pros

• Durable cobalt material improves wear resistance and permits higher cutting speeds compared with standard HSS.
• Sharp, clean cuts in tough materials with good drill performance and reduced clogging thanks to spiral flutes.
• Round shanks and jobber length make the set versatile for many toolholders and general drilling tasks.
• Manufactured to a recognized aerospace standard for reliable dimensions and quality.

Cons

• The thin gold oxide finish is mainly identification rather than a high-performance coating, so it performs similarly to uncoated bits in some conditions.
• Users seeking specialized shank types or occasional light-duty users may find the set overbuilt for simple home tasks.

Specifications

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

Our Verdict

The Drill America L Cobalt pack of 12 is a practical choice for professionals and dedicated hobbyists who need reliable cobalt drill bits that last longer and run faster in tough metals. Its construction, spiral flute design and aerospace manufacturing standard make it good value for those drilling stainless, titanium or nickel alloys, while casual users may prefer a simpler, lower-cost set.

Frequently Asked Questions

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

Can I use them in a handheld drill?
Yes, the round shanks work in most chucks, but ensure your drill and speed settings match recommended rates for cobalt bits.

Does the gold oxide coating improve cutting life?
The gold oxide is a thin surface treatment mainly for identification and mild corrosion resistance; the life advantage comes primarily from the cobalt material itself.