27/64 in Cobalt Heavy Duty Drill Bit Pack of 6 - Long Life Cuts

In this review the Drill America 27/64 in cobalt heavy duty drill bit pack is assessed for users who need a durable bit for tough metals. The bottom line: this jobber length set is best for machinists and fabricators who drill stainless steel, nickel alloys or other high tensile materials because the added cobalt raises red hardness and allows higher cutting speeds, delivering noticeably longer life and consistently sharp performance compared with ordinary HSS bits.

Key Features

• Cobalt steel construction: Provides higher heat resistance and higher red hardness so the bits cut harder metals with less wear.
• Gold oxide finish: A thin oxide surface helps identify the tool and offers similar performance to uncoated bits while resisting light corrosion.
• Round shank: Fits a wide variety of chucks and toolholders so the bits are easy to adapt in most shops.
• Spiral flutes: Right-hand spiral evacuates chips up and out of the hole to reduce clogging and keep cuts cleaner.
• National Aerospace standard 907: Manufactured to an exacting aerospace standard that indicates consistent geometry and quality control.

Who It's For

The Drill America 27/64 in cobalt bits are aimed at professional users and serious hobbyists who regularly drill high tensile or heat-resistant alloys such as PH stainless, inconel and titanium; they are well suited to machine shops, metal fabrication and maintenance departments that need longer life from a jobber drill bit. The set is also useful where speed and wear resistance matter, since the cobalt permits up to about 30 percent higher cutting speeds than standard HSS.

Those who primarily drill soft materials like wood, plastics or soft mild steel and who only need occasional holes may find less advantage from cobalt bits and could choose lower cost HSS bits instead; likewise, buyers who require specialized coatings for extreme lubricity should consider coated variants made specifically for that purpose.

Pros & Cons

Pros

• Durable cutting edge that holds sharpness for longer life on hard metals.
• Permits higher operating speeds than HSS, improving throughput in demanding jobs.
• Round shank and jobber length make the bits versatile for many chucks and setups.
• Consistent manufacturing to NAS 907 gives predictable performance across the pack.

Cons

• Gold oxide is a thin treatment and offers performance similar to uncoated bits, so buyers wanting advanced coatings for reduced friction may look elsewhere.

Specifications

Diameter	27/64 in
Material	Cobalt steel (heat resistant)
Pack quantity	6 pieces
Shank type	Round shank
Finish	Gold oxide (thin oxide)
Length	Jobber length
Standard	Manufactured to National Aerospace standard 907

Our Verdict

The Drill America 27/64 in cobalt jobber bit pack is a solid choice for professionals who drill tough alloys and need durable, sharp bits that tolerate higher speeds. It delivers good value through longer life and consistent manufacturing, though those who want specialty coatings for extreme lubrication should shop coated options. For general metalworking and shop use this pack is a practical, cost-effective pick.

Frequently Asked Questions

Are these bits suitable for stainless steel?
Yes. The cobalt steel construction increases red hardness and is especially effective for drilling stainless steel and other high tensile materials.

Will the gold oxide coating improve cutting life?
The gold oxide is a thin oxide finish mainly for identification and mild corrosion resistance; performance is similar to uncoated cobalt bits rather than advanced coated tools.

Do these fit common drill chucks?
Yes. The round shank design allows use with a wide variety of chucks and toolholding systems.