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Cobalt jobber drill bit, 31/64 inch, black oxide finish, split point

Cleveland Golf

Cleveland Golf 31/64 in. Cobalt Jobber Drill Bit 135° Split Point Black Oxide

SKU CH-0T87-G9DK7

A 31/64 in. cobalt jobber drill bit with a 135° split point and black oxide finish for alloy, carbon, stainless and tool steel

  • Product typeAlignment Tools
  • 31/64 inch cobalt steel drills tough alloys
  • 135° split point starts holes without wandering
  • Black oxide finish resists wear and corrosion
  • Heavy-duty grade handles stainless and tool steel
  • 5-7/8 inch overall length gives 4xD reach

31/64 in. Cobalt Jobber Drill Bit

This 31/64 inch cobalt jobber drill bit is built for drilling alloy, carbon, stainless and tool steel. The 135 degree split point reduces walking and starts holes cleanly. A black oxide finish adds wear resistance and lubricity during heavy duty use.

Fits 31/64 inch shank capacity

Machinists and maintenance technicians drilling 0.4844 inch holes in hard metals will benefit from the cobalt substrate and split point geometry. Users needing coolant through tooling or a different diameter should select another bit.

135 degree split point geometry

The 135 degree split point is the critical specification that enables self centering and lower thrust in tough steels. It determines whether this bit matches the drilling requirements for the intended material and application.

How it compares

Measured against everything we stock in Utility & Specialty Hand Tools, at today’s prices. Recalculated every night.

Price $24.99
Typical for this category: the median of 2,474 items is $23.99.

Specifications

Product
Brand nameCleveland
Product typeAlignment Tools

Questions about this item

How often will the 135° split point on this 31/64 in. cobalt bit need resharpening?

The 135° split point is designed for heavy-duty use in alloy, carbon, stainless and tool steels; resharpen when cutting edges show visible wear or feed pressure increases noticeably.

What limits continuous drilling depth with the 4-3/8 in. flute length?

The 4xD depth-to-diameter ratio and 4-3/8 in. flute length mean chips must be cleared before exceeding roughly four times the 31/64 in. diameter in a single plunge.

How much heat builds up in the black-oxide cobalt steel during all-day right-hand cutting?

Cobalt steel with black-oxide finish resists heat buildup better than high-speed steel, but sustained high-speed drilling in stainless or tool steel will still require periodic cooling pauses.

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