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Gold TiN-coated cobalt jobber drill bit, split point, 135-degree angle

Chicago-Latrobe

Chicago-Latrobe 54109 135° Cobalt Jobber Drill Bit J .2770 TiN

SKU CH-K783-JES8Y

Cobalt jobber drill bit with a 135° split point and TiN coating for drilling hard materials

  • Product typeDrill Bits
  • Main materialHAWA
  • 135° split point starts on contact without walking
  • Cobalt steel resists heat for longer cutting life
  • TiN coating reduces friction and extends bit durability
  • Jobber length suits general-purpose drilling tasks
  • Decimal size .2770 matches J letter gauge precisely

Chicago-Latrobe 54109 Cobalt Drill Bit J

The Chicago-Latrobe 54109 is a jobber-length drill bit sized to letter J with a decimal equivalent of .2770. It is made from cobalt steel with a titanium nitride coating for hardness and heat resistance. The 135-degree split point reduces walking and starts holes cleanly in metal. It is suited for mechanics and fabricators who need a durable bit for repeated drilling in tough alloys.

Who this suits and who should look elsewhere

This bit suits users drilling stainless steel, titanium or high-strength steels where cobalt retains its edge longer than high-speed steel. It is not for buyers who need a larger diameter than .2770 or a different letter size. It is not for applications requiring coolant-through capability or multiple coolant holes. It is not for wood, plastic or masonry work where a standard twist bit is more appropriate.

Decisive specification: letter J diameter .2770

The single specification that decides fit is the drill bit size J with a decimal equivalent of .2770. If the hole you must produce matches this exact diameter, the bit is the correct part. If the required diameter differs, this bit will not work regardless of its cobalt construction or TiN coating.

How it compares

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

Price $9.99
Cheaper than about 88% of the 5,493 comparable items (median $27.99).

Specifications

Product
Brand nameCHICAGO-LATROBE
Product typeDrill Bits
Size & build
Main materialHAWA

Questions about this item

What drill chuck size do I need to hold the .2770 inch shank on this 54109 bit?

A standard three-jaw chuck that opens to at least .2770 inch will hold the jobber-length shank; most 3/8 inch or 1/2 inch capacity chucks meet that requirement.

Will the 135 degree cobalt tip cut through the hardened steel bolts I normally drill with high-speed steel bits?

The cobalt alloy and TiN coating are designed for hard metals such as stainless and heat-treated steel, so it will outlast standard HSS bits in those materials.

How can I confirm the split point is centring correctly on first contact?

The 135 degree split point should self-centre without a centre punch; if the bit walks, check that the chuck is tight and the workpiece is clamped rigidly.

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