Drill America 15/32 in Cobalt Drill Bit Pack of 6 - Tough Metal

In this review the Drill America 15/32 in Cobalt Drill Bit pack of 6 is assessed for machinists and metalworkers who need reliable bits for hard materials; the single biggest reason to buy is its heat-resistant cobalt construction that stays sharp longer when cutting high tensile alloys. These jobber length bits are manufactured to National Aerospace standard 907 and are designed for higher red hardness than standard high-speed steel, which makes them suited to drilling stainless steel, high carbon steel, and other tough metals where durability and cutting speed matter.

Key Features

• Cobalt construction: Heat resistant cobalt steel permits higher red hardness so the bit maintains cutting edge under heavy use and higher speeds.
• Gold oxide finish: A thinner oxide surface treatment reduces surface corrosion and provides visual identification without changing cutting performance.
• Round shank: Round shanks fit a wide variety of toolholding systems for use in drills, drill presses, and stand-mounted tools.
• Spiral flute geometry: Right-hand spiral flutes evacuate chips up and out of the hole to reduce clogging while drilling deeper cuts.
• Manufacturing standard: Made to National Aerospace standard 907, offering consistent geometry and tolerance suitable for demanding metalworking tasks.
• Jobber length: General-purpose length balances rigidity and reach for common shop tasks on metal and thick stock.

Who It's For

These drill bits are aimed at hobby machinists, fabrication shops, and maintenance technicians who frequently drill hard materials like stainless steel, titanium, or high carbon alloys and need bits that tolerate higher speeds and sustained heat. The pack of six at 15/32 in is convenient for jobs requiring multiple spares or repeated holes of the same size.

Users who primarily work with soft materials or who need specialized coated drills for extreme wear resistance may prefer a different bit type; also, if precise metric sizing or indexable tooling is required for production tolerance control, these jobber bits are more of a general-purpose choice.

Pros & Cons

Pros

• High red hardness from cobalt construction delivers better life and elevated cutting speeds compared with standard HSS.
• Gold oxide finish helps identify the material and resists light corrosion without changing cutting feel.
• Round shanks and jobber length make them versatile across common toolholders and drill applications.
• Manufactured to aerospace standard for consistent quality and reliable geometry.

Cons

• Some customers report occasional size variation compared with descriptions, so careful checking before critical holes is advised.
• Performance is similar to uncoated tools for some applications, so more advanced coatings are not present for extreme wear resistance.

Specifications

Brand	Drill America
Size	15/32 in
Quantity	Pack of 6
Material	Cobalt steel (heat resistant)
Finish	Gold oxide
Length style	Jobber length
Standard	Manufactured to National Aerospace standard 907

Our Verdict

The Drill America 15/32 in cobalt drill bit pack is a solid, value-focused choice for those who drill hard metals and need durable, heat-resistant bits. With aerospace standard manufacture and useful jobber length, it offers dependable performance for general metalworking; buyers seeking advanced coatings or absolute size precision should verify fit before production use, but for most shop and field work it represents good value and consistent durability.

Frequently Asked Questions

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

Will the gold oxide finish improve cutting speed?
The gold oxide is a thin surface treatment for identification and light corrosion resistance; it does not materially change cutting speed compared with uncoated cobalt bits.

Do these bits fit standard chucks?
Yes, the round shank design fits the wide variety of standard drill chucks and toolholding systems used in shops.