Cobalt Drill Bit Set 115 PCS - Durable M35 Bits in Metal Case

Our review of the Cobalt Drill Bit Set 115 PCS finds it best suited for the serious DIYer, professional tradesperson, or anyone who regularly drills into hard metals. The single biggest reason to buy is the set's broad size coverage combined with M35 cobalt construction, which delivers noticeably better wear resistance when tackling stainless steel, cast iron, and other hard alloys. The review highlights the practical metal index storage box and the 135-degree split point geometry that reduces walking, making this kit a dependable everyday assortment.

Key Features

• 115-piece assortment: Includes 29 fractional bits, 26 letter sizes, and 60 wire sizes so users rarely need an extra bit for standard tasks.
• M35 cobalt construction: Contains 5% cobalt alloy for improved hardness and wear resistance when drilling stainless steel and high-temperature alloys.
• 135-degree split point: The self-centering tip minimizes walking and speeds up hole starts in metal and wood.
• Fully ground twist design: Reduces friction for cooler drilling and longer bit life during extended use.
• Round straight shank: Compatible with standard chucks and easy to secure in most drills and drivers.
• Metal index storage box: An ergonomic, portable case with a clip for organized carrying and quick bit selection on the job.

Who It's For

This set is aimed at professionals and committed hobbyists who need a one-stop kit that covers fractional, letter, and wire gauges for everyday drilling into metal, wood, and plastics. The M35 cobalt alloy and split point geometry make it especially useful for mechanics, metal fabricators, and contractors who frequently encounter stainless steel or high-strength alloys.

Less technical users who only drill occasional holes in soft wood or soft metals might find many of these specialized sizes unnecessary and could consider a smaller, simpler set. Also, if absolute ultimate toughness for industrial, high-volume production is required, users should compare with dedicated industrial jobber sets designed for heavy continuous duty.

Pros & Cons

Pros

• Comprehensive size range that reduces the need to buy individual bits later.
• Good cutting performance on hard metals thanks to 5% cobalt alloy construction.
• Storage box keeps bits organized and portable with an attached clip for on-belt carry.

Cons

• Customer feedback on durability is mixed; some users report breakage with heavy use while others find them long-lasting.
• Case fit and internal layout have mixed reviews, so organization experience may vary by unit.

Specifications

Set contents	115 pcs (29 fractional, 26 letter, 60 wire)
Fractional range	1/16 to 1/2 in in 1/64 in increments
Letter sizes	A to Z
Wire sizes	#1 to #60
Material	M35 high speed steel with 5% cobalt
Tip geometry	135-degree split point
Storage	Metal index storage box with clip

Our Verdict

The Cobalt Drill Bit Set 115 PCS is a well-rounded, cost-effective kit for professionals and avid DIYers who need reliable performance on stainless steel and other tough materials. Its extensive size selection and cobalt alloy construction make it a strong value for general workshop and on-site use, though buyers should note some variability in case fit and long-term durability reported by users.

Frequently Asked Questions

Are these bits suitable for stainless steel?
Yes, the M35 cobalt composition and 135-degree split point are intended to cut stainless steel and other hard alloys effectively.

Does the kit include a storage case?
Yes, the set ships in a metal index storage box with a built-in clip for easy carrying and organization.

Will these fit a standard drill chuck?
Yes, the bits have round straight shanks compatible with most standard drill chucks and drivers.