Drill America L Cobalt Drill Bit Pack of 12 - Tough Metal Drilling

Our review of the Drill America L Cobalt Drill Bit pack finds these jobber length bits most useful for tradespeople and serious DIYers who frequently drill hard metals. The single biggest reason to buy is durability: made from heat resistant cobalt with higher red hardness, these bits cut tougher materials and maintain sharpness longer than ordinary high-speed steel. For anyone working on stainless steel, nickel alloys, high carbon steel, or aluminum, the consistent performance and ability to run at higher speeds make this a practical set to keep in a toolbox.

Key Features

• Cobalt steel construction: Provides improved wear resistance and the ability to sustain higher cutting speeds when working stainless steel and nickel alloys.
• Gold oxide surface treatment: A thin oxide finish that helps identify the tool and offers protection similar to uncoated bits without affecting cutting geometry.
• Round shank design: Fits a wide variety of toolholding systems so the bits are easy to use in most drill chucks and holders.
• Right-hand spiral flute: Evacuates chips up and out of the hole to reduce clogging when drilling through tougher materials.
• Manufactured to NAS 907: Built to a recognized aerospace standard for consistent form and performance across the set.

Who It's For

These drill bits are aimed at professionals and experienced hobbyists who need a reliable set for drilling hard, high tensile materials such as PH stainless, inconel, titanium and thick high carbon steel. The set is most valuable where longevity and heat resistance matter, for example in fabrication shops, maintenance crews, and automotive work.

Casual users who only drill soft woods or occasional sheet metal may be better served with simpler HSS bits or cheaper kits, since the cobalt construction is a premium feature mainly needed for tougher alloys and repeated heavy work.

Pros & Cons

Pros

• Well made and durable, staying sharp through repeated use on galvanized and high carbon steel according to users.
• Higher red hardness permits faster cutting speeds than typical HSS, improving efficiency on tough metals.
• Round shanks and standard jobber length make the bits versatile in common drill chucks.
• Gold oxide finish identifies the bits without changing cutting performance.

Cons

• Not coated for extended life like some specialized coatings, so extreme wear resistance depends on proper use and cooling.
• Some users reported mixed impressions about sizing, so double-check the specific diameters required for a project.

Specifications

Our Verdict

For professionals and dedicated hobbyists who drill tough alloys regularly, this pack of cobalt jobber length bits offers reliable durability, higher allowable speeds, and predictable chip evacuation, making it a good value. Those who only drill soft materials may not need the extra cost, but for demanding metal work these bits are a practical, long-lasting choice.

Frequently Asked Questions

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

Do they fit standard drill chucks?
Yes, the round shanks are compatible with most drill chucks and common toolholding systems.

Is the gold oxide a performance coating?
The gold oxide is a thin oxide finish for identification and minor protection; performance is similar to uncoated cobalt tools.