47/64 in Cobalt Drill Bits 3 Pack - Durable M35, 6 in Length

In this review the 47/64 in Cobalt Drill Bits 3 Pack is judged for users who frequently drill hard metals and need a consistent, ready-to-use set. The biggest reason to buy is the combination of M35 construction with a 135 split point that starts cleanly and maintains a precise diameter through repeated holes in stainless and hardened steels. The included plastic storage case keeps the set organized, so a mechanic, machinist or serious DIYer gets both durable bits and convenient storage in one purchase.

Key Features

• 47/64 in Diameter: Provides a large, consistent hole size for applications that require this specific diameter without guessing or regrinding.
• M35 Construction: The bits contain 5% cobalt for improved hardness and heat resistance when drilling metals like stainless and hardened steel.
• 135 Split Point: The split point geometry reduces walking and makes it easier to start and repeat holes in tougher materials.
• 6 in Total Length: With a 3 in flute length and 6 in overall length, the bits reach deeper pockets while maintaining rigidity for controlled drilling.
• Plastic Storage Case: A tough plastic case is included to protect the bits in a toolbox and keep them organized between jobs.

Who It's For

The pack is best suited to professional tradespeople and experienced hobbyists who regularly drill through metals such as stainless steel, cast iron, titanium and hardened steel, and who need a reliable 47/64 in size with good heat resistance. It also fits shop environments where repeated holemaking demands a consistently ground diameter.

Those who primarily drill wood, masonry, or only occasional small holes in thin metals should look elsewhere for smaller, cheaper bits optimized for those materials; this set is purpose-built for metalwork and is overkill for light household tasks.

Pros & Cons

Pros

• High hardness from M35 cobalt alloy gives better wear resistance when cutting tough metals.
• 135 split point improves centering and reduces the need for pilot holes on metal surfaces.
• Fully ground flutes maintain a precise drilling diameter and smooth cutting action.
• Included durable plastic case keeps each bit secure and easy to transport.

Cons

• Durability reports are mixed; some users find the bits break more easily under heavy misuse or extreme bind than expected.
• The single diameter pack limits versatility if you need a range of hole sizes for general work.

Specifications

Pack Quantity	3
Diameter	47/64 in
Flute Length	3 in
Total Length	6 in
Material	M35 cobalt (5% cobalt)
Tip Geometry	135 split point, fully ground
Storage	Plastic storage case included

Our Verdict

This 47/64 in cobalt drill bit 3 pack is a practical choice for metalworkers who need a reliable, precisely ground bit with good heat resistance and easy starts from the 135 split point. For tasks that demand consistent large-diameter holes in stainless or hardened steel, the set offers good value thanks to M35 construction and the protective case, though buyers should respect proper speeds and feed to avoid premature breakage.

Frequently Asked Questions

Are these bits suitable for stainless steel?
Yes. The M35 5% cobalt composition and split point geometry are designed to cut stainless and other hard metals effectively.

Does the pack include a case?
Yes. A tough plastic storage case is included to keep the three bits organized and protected.

What length and flute depth do these bits have?
Each bit has a 6 in total length with a 3 in flute length, suitable for deeper holes while retaining rigidity.