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

In this review the Drill America 31/64 in Cobalt Drill Bit pack is evaluated for metalworkers and serious DIYers who need a durable twist drill that holds an edge. The single biggest reason to consider this set is the heat resistant cobalt steel construction that lets the bits run hotter and cut tougher alloys than standard high-speed steel, making them a practical choice when drilling stainless steel, nickel alloys, or other high tensile materials.

Key Features

• Cobalt steel: Higher red hardness allows drilling at greater speeds and improves life when working hard metals.
• Gold oxide finish: A thin oxide surface treatment identifies the tool and offers similar performance to uncoated bits while resisting light corrosion.
• Round shank: Easily fits a wide variety of chucks and toolholding systems for shop or jobsite use.
• Right-hand spiral flutes: Evacuate chips up and out of the hole to reduce clogging and help maintain cutting efficiency.
• Jobber length: Balances reach and rigidity for general purpose drilling without excessive flex in most handheld and drill press applications.

Who It's For

The pack is aimed at mechanics, fabricators, and metalworking hobbyists who routinely drill tough materials such as PH stainless, high carbon steel, or thin-gauge galvanized sheet and need bits that stay sharp under heavier cutting conditions. The set suits users who prefer standard jobber length bits with a versatile round shank for multiple chucks.

Those who primarily drill wood, soft plastics, or need specialty point geometries for angled entry should consider other bits optimized for those tasks, since these bits are specifically made to handle hard metals and the geometry is tailored for that purpose.

Pros & Cons

Pros

• Excellent durability and sharpness retention when cutting harder metals.
• Higher cutting speeds than HSS due to cobalt content for improved productivity.
• Good value for money as a multi-pack for frequent metal drilling jobs.

Cons

• Size opinions are mixed among users, so confirm 31/64 in is the size you need for your application.

Specifications

Our Verdict

The Drill America 31/64 in cobalt jobber bits are a solid choice for professionals and serious hobbyists who need reliable performance in hard metals. They offer durable cutting life, the ability to run hotter than HSS, and practical compatibility with common chucks, making the pack a cost-effective option for repetitive metal drilling tasks.

Frequently Asked Questions

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

Do they fit standard drill chucks?
Yes; the round shank is compatible with a wide variety of toolholding systems and standard chucks.

Is the gold oxide coating a hard protective layer?
The gold oxide is a thin surface treatment mainly for identification and light corrosion resistance; performance is similar to uncoated cobalt bits.