31/64 in Cobalt Heavy Duty Drill Bit Pack of 6 - Jobber Length

In this review the Drill America 31/64 in cobalt heavy duty drill bit pack is evaluated for tradespeople and metalworkers who need a durable, high-performance bit for tough alloys. The bottom line: this jobber length, heat resistant cobalt set stands out for drilling hard materials such as stainless steel, inconel and titanium and is worth considering when longevity and higher cutting speeds matter. The review focuses on build, cutting performance and value based on materials and customer feedback.

Key Features

• Cobalt construction: The higher cobalt content raises red hardness and lets the bit run up to 30 percent faster than standard high-speed steel in demanding metals.
• Gold oxide finish: A thin oxide surface treatment protects the flutes and makes the bits easy to identify while maintaining cutting performance similar to uncoated tools.
• Round shank: The round shank design fits a wide variety of chucks and toolholding systems for straightforward use on drill presses and hand drills.
• Spiral flute geometry: Right-hand spiral flutes evacuate chips up and out of the hole to reduce clogging when drilling deep or abrasive materials.
• Manufactured to NAS 907: Built to National Aerospace standard 907, the bits offer consistent geometry and quality control suited to industrial applications.

Who It's For

The Drill America 31/64 in cobalt jobber bits are aimed at metalworkers, fabricators, maintenance techs and serious hobbyists who regularly drill high tensile alloys like PH stainless steel, inconel and titanium and need bits that hold an edge and tolerate higher cutting speeds. Their ability to run hotter and cut harder materials makes them a sensible upgrade from ordinary high-speed steel bits.

Those who primarily drill soft materials, wood or occasional light-duty tasks may find cobalt bits overkill and could opt for cheaper HSS or titanium-coated options. If you need fractional sizes in quantity or specialized coatings beyond gold oxide, consider other specialty sets tailored to that use.

Pros & Cons

Pros

• Durable cutting edge that lasts longer in hard alloys, offering clear value for money.
• Higher red hardness permits faster cutting speeds compared with standard HSS drills.
• Round shanks provide compatibility with many chucks and holders for easy swapping.
• Manufactured to aerospace standard 907 for reliable geometry and repeatable performance.

Cons

• Gold oxide is a light surface treatment and offers limited additional wear protection compared with thicker coatings.
• Jobber length may not suit very deep hole applications without extension or specialized tooling.

Specifications

Our Verdict

The Drill America 31/64 in cobalt jobber bit pack is a strong choice for professionals and serious DIYers who drill tough, high-strength metals and need longer life and higher cutting speeds than HSS provides. Given its construction, compatibility and aerospace manufacturing standard, it represents solid value for money for metalworking applications.

Frequently Asked Questions

Can these bits drill stainless steel?
Yes, the cobalt composition and higher red hardness make them well suited for stainless steel and other high tensile alloys.

Will the gold oxide coating improve wear life?
The gold oxide is a thin surface treatment for identification and minor protection; it does not provide the thicker wear resistance of specialty hard coatings.

Are they compatible with standard drill chucks?
Yes, the round shank design fits most standard chucks and toolholding systems.