#5 Cobalt Heavy Duty Drill Bit Pack of 12 - Durable Jobber Drills

In this review the focus is on the Drill America #5 Cobalt Heavy Duty Drill Bit pack of 12, a jobber-length set made for cutting tougher metals. The bottom line: this pack is aimed at tradespeople and hobbyists who regularly drill stainless steel, nickel alloys or other high tensile materials and need a durable, sharp drill that tolerates higher speeds than standard high-speed steel. The single biggest reason to buy is the bit material and construction, which deliver sustained cutting performance and longer life when working on hard metals.

Key Features

• Cobalt steel construction: Provides better red hardness for prolonged cutting life in high tensile materials compared with standard high-speed steel.
• Gold oxide finish: A thin surface treatment that identifies the bits and offers similar performance to uncoated tools while easing chip flow.
• Round shanks: Compatible with a wide variety of toolholding systems so the bits fit most chucks and holders.
• Right-hand spiral flute: Evacuates chips up and out of the hole when run in the counterclockwise direction to reduce clogging on deep cuts.
• Manufactured to aerospace standard: Produced to National Aerospace standard 907, indicating consistent geometry and quality control for demanding jobs.

Who It's For

These drill bits suit professional fabricators, machinists and serious DIYers who frequently drill through stainless steel, inconel, titanium or other high strength alloys and need a reliable, hard-wearing jobber-length bit. The pack of 12 is useful for shops that want spares and consistent performance across multiple tools.

Those who primarily drill soft materials, need specialized coatings for reduced friction on high-production runs, or require non-round shanks for keyed holders may prefer other bit types. This set is not aimed at casual users who never work with high tensile metals.

Pros & Cons

Pros

• High durability and sharpness from cobalt steel, giving longer life in tough metals.
• Good value for money when buying a pack of 12 for regular workshop use.
• Consistent manufacturing to aerospace standard 907 yields reliable geometry and performance.
• Round shanks and spiral flutes improve compatibility and chip evacuation on through-holes.

Cons

• Gold oxide is a light surface treatment and offers performance similar to uncoated bits, so it may not provide the low-friction benefits of specialized coatings.
• Jobber length may flex more than stub or reduced-shank types on very deep, high-precision holes.

Specifications

Our Verdict

The Drill America #5 cobalt jobber drill pack is a practical choice for anyone who regularly works with stainless steel or other high tensile alloys and needs durable, sharp bits that run hotter and faster than HSS. The pack offers solid value and dependable geometry to keep a shop running without frequent bit changes.

Frequently Asked Questions

Are these bits good for stainless steel?
Yes, the cobalt steel formulation and higher red hardness make them well suited to stainless and other hard alloys.

Will the gold oxide coating improve life?
The gold oxide is a thin surface treatment that mainly identifies the material; performance is similar to uncoated bits, so longevity comes mostly from the cobalt steel itself.

Do these require a special chuck?
No, the round shanks are compatible with most common chucks and toolholding systems.