Cobalt Jobber Drill Bit Pack (6) - Tough Metal Cutting Performance

In this review the Drill America T Cobalt Drill Bit pack (DWDCO Series) is examined as a straightforward set of jobber length drills aimed at cutting tougher metals. The bottom line: this six-pack is best for metalworkers who need durable, heat-resistant bits that stay sharp while drilling high tensile materials. The single biggest reason to buy is the higher red hardness of the cobalt steel, which allows faster cutting and longer life compared with standard high-speed steel when working with stainless, nickel alloys or other hard metals.

Key Features

• Cobalt steel construction: provides improved wear resistance and higher red hardness so bits tolerate heat and maintain cutting ability in tough metals.
• Gold oxide finish: a thin oxide surface treatment offers corrosion protection without changing cutting performance versus uncoated bits.
• Round shank design: fits a wide variety of chucks and toolholding systems for flexible use in drill presses and hand drills.
• Right-hand spiral flute: evacuates chips up and out of the hole to reduce clogging and help maintain drill accuracy.
• Manufactured to NAS 907: produced to a recognized aerospace standard, which speaks to consistent geometry and build quality.

Who It's For

The pack is suited to machinists, maintenance techs, and hobbyists who regularly drill stainless steel, high carbon steel, inconel or titanium and need bits that can run hotter and last longer than standard HSS. It is also a practical choice for anyone wanting a modest set of jobber length bits that perform well in tougher alloys without specialized coatings.

Those who should look elsewhere include users who only drill soft materials infrequently, where cheaper HSS bits suffice, or users who require coated bits specifically engineered to reduce friction in high-speed production environments, since the gold oxide here is a thinner surface treatment and not a low-friction industrial coating.

Pros & Cons

Pros

• Durable cutting edges that remain sharp through repeated use in 16 and 18-gauge galvanized steel and thicker high carbon steel.
• Higher recommended speeds than HSS, enabling faster cutting in high tensile materials due to elevated red hardness.
• Compatible round shanks and spiral flute geometry make chip evacuation reliable and keep drills from clogging.
• Good value for money as a six-piece jobber set made to a recognized aerospace standard.

Cons

• Geometry feedback is mixed among users, so a small number of buyers may find individual bit angles or sizes less than ideal for their exact tasks.
• The gold oxide is a thin surface treatment and does not provide the same low-friction advantage as some thicker, modern coatings.

Specifications

Brand	Drill America
Series	DWDCO
Material	Cobalt steel (heat resistant)
Finish	Gold oxide thin surface treatment
Shank	Round shank
Flute	Right-hand spiral fluted
Manufacturing Standard	National Aerospace Standard 907

Our Verdict

The Drill America T Cobalt jobber pack is a sensible buy for anyone who needs dependable drill bits for stainless, high carbon steels and other tough alloys; the cobalt construction and higher red hardness deliver longer life and faster cutting than standard HSS. Given the build quality and NAS 907 manufacturing standard, it represents solid value for metalworking tasks where durability and heat resistance matter.

Frequently Asked Questions

Are these bits suitable for stainless steel?
Yes, the cobalt composition is designed for cutting stainless and other high tensile alloys and performs better than standard high-speed steel.

Do the bits fit standard drill chucks?
Yes, the round shank design fits most standard chucks and common toolholding systems used in shops and by hobbyists.

Is the gold oxide a heavy coating?
No, the gold oxide is a thin oxide treatment that provides some surface protection but performs similarly to uncoated bits in cutting action.