We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Cobalt screw machine drill bit, X size, 135 degree split point, straw finish

Chicago-Latrobe

Chicago-Latrobe 50853 Cobalt Screw Machine Drill Bit X 135° .3970

SKU CH-9ARH-7NGYE

Cobalt screw-machine drill bit with 135° split point, X size (.3970), right-hand cutting

  • Product typeDrill Bits
  • Cobalt steel resists heat during high-speed drilling
  • 135° split point starts holes without wandering
  • Right-hand cutting clears chips efficiently
  • Straw finish identifies cobalt construction instantly
  • Decimal size .3970 matches X gauge precisely

Cobalt drill bit for screw machines

This CHICAGO-LATROBE 50853 drill bit is made from cobalt steel for hardness and heat resistance. It is sized to X with a decimal equivalent of .3970 inches. The tool suits machinists and maintenance technicians drilling precise holes in tough alloys.

Split point and 135 degree angle

A 135 degree split point centres the bit on contact and reduces walking on hard surfaces. The right-hand cutting direction matches standard drill motors and CNC spindles. The straw finish identifies the cobalt material without a coating that could mask wear.

Non-coolant-through limitation

The bit lacks internal coolant passages so chips must be cleared by peck drilling or external flood coolant. Deep holes in stainless or high-temp alloys will need frequent withdrawal to prevent packing. Users needing through-tool coolant should select a different design.

How it compares

Measured against everything we stock in Bits, Hole Saws & Accessory Kits, at today’s prices. Recalculated every night.

Price $11.99
Cheaper than about 84% of the 5,493 comparable items (median $27.99).

Specifications

Product
Brand nameCHICAGO-LATROBE
Product typeDrill Bits

Questions about this item

What does the 135-degree split point do for the Chicago-Latrobe 50853 cobalt bit?

The 135-degree split point reduces walking and starts the hole on contact, which is useful when drilling harder materials with a handheld or stationary drill.

What shank style does the Chicago-Latrobe 50853 use so I know if it fits my chuck?

It has a straight round shank that matches the decimal size .3970, so any three-jaw chuck that opens to at least that diameter will hold it.

What is the correct way to install this cobalt screw-machine bit and what step is often missed?

Open the chuck fully, insert the bit until the shank seats against the jaws, then tighten securely; the step often missed is verifying the bit runs true before applying feed pressure.

More in Bits, Hole Saws & Accessory Kits

Similar items