115Pcs Cobalt Drill Bit Set (1/16ft - 1/2ft) - Complete M35 Jobber Kit

In this review of the 115Pcs Cobalt Drill Bit Set the bottom line is simple: this kit is for hobbyists, home workshop owners, and tradespeople who need a broad range of durable drill sizes for metal and mixed materials. The set stands out because it combines an extensive size range-fractional, letter, and numbered bits-with M35 cobalt HSS construction and a metal index box for organized storage. For anyone drilling stainless steel, cast iron or hardened bolts, the main reason to buy is the material and tip geometry that deliver sharper cutting and better heat resistance than ordinary bits.

Key Features

• 115-piece range: Includes 29 fractional sizes, 26 letter sizes and 60 numbered sizes, offering near-universal coverage for workshop needs.
• M35 cobalt construction: Hardened cobalt alloy provides improved wear resistance and maintains edge strength when drilling tougher metals like stainless steel.
• 135-degree point tip: Self-centering tip reduces walk-off and helps start holes cleanly in metal and thin materials.
• Jobber length twist design: The twist flutes remove chips efficiently for faster cutting and reduced binding during longer drills.
• Metal index storage box: The included holder with size index keeps bits organized and easy to find, saving time on job sites and in the garage.

Who It's For

The kit suits DIYers, mechanics and metalworkers who want a single set that covers fractional, letter and numbered sizing for varied projects. It is particularly useful for those who work with stainless steel, cast iron and other tougher metals because the M35 cobalt formulation holds up better under heat and friction than standard HSS.

Those who only occasionally drill soft wood or plastics and want a few basic sizes might find this set more comprehensive than necessary; similarly, users seeking ultra-long drill lengths or specialized coatings should consider dedicated specialty bits instead.

Pros & Cons

Pros

• Extensive size selection eliminates the need to buy multiple separate sets.
• M35 cobalt bits deliver sharpness and durability for cutting hardened metals.
• 135-degree point and twist design aid in faster cutting and reduced bit walking.
• Sturdy metal index box keeps bits organized and labeled for quick selection.

Cons

• Some customers reported mixed durability on the smallest bits, which is a realistic limitation for tiny diameters under heavy use.

Specifications

Our Verdict

The 115Pcs Cobalt Drill Bit Set is a strong value for users who need a comprehensive collection of durable bits for metal and mixed-material work. The M35 cobalt build and 135-degree tip give confident cutting in stainless and cast iron, while the organized metal case keeps the wide size range usable. Buy this set if you want one kit to handle most shop and repair tasks without constant bit changes.

Frequently Asked Questions

Can these bits drill stainless steel?
Yes, the M35 cobalt composition and 135-degree tip make them suitable for stainless steel and other harder metals when used with correct speed and lubrication.

Does the set include a storage solution?
Yes, it ships with a metal index box that contains labeled slots for fractional, letter and numbered bits for easy organization.

Are the smallest sizes durable?
Small diameter bits can be fragile under heavy misuse; customers report generally good sharpness but mixed durability on the very smallest sizes, so handle those with care.