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Cobalt jobber drill bit, gold TiN finish, 135 degree split point, size .3770

Chicago-Latrobe

Chicago-Latrobe 54121 135 Degree Cobalt Drill Bit .3770

SKU CH-4P2F-RXS9A

A 135-degree split-point cobalt jobber drill bit sized .3770 for hard-metal drilling

  • TypeDrill Bits
  • MaterialHAWA
  • 135-degree split point starts on contact without walking
  • Cobalt steel with TiN coating resists heat and wear
  • Jobber length suits general-purpose drilling in metal
  • Size V (.3770 in) fits precise hole requirements
  • Heavy-duty construction handles tough materials cleanly

135 Degree Split-Point Cobalt Drill Bit

The Chicago-Latrobe 54121 is a jobber-length twist drill made from cobalt steel with a titanium nitride coating. Its 135 degree split-point geometry reduces walking and starts cleanly on hard materials. The bit suits mechanics and fabricators who need reliable holes in stainless steel or tough alloys.

Sustained drilling in hard metals

Cobalt alloy retains hardness at the elevated temperatures produced by extended cutting in stainless steel, titanium and high-strength alloys. The TiN surface lowers friction and resists built-up edge, so cutting speeds stay consistent through a full shift. The split point keeps centring accurate without a separate centre punch.

Jobber length and material limits

Jobber proportions give standard reach for through-holes in plate and bar stock, but flute length limits chip evacuation in deep holes. The .3770 inch diameter matches letter-size V specifications for close-tolerance work. Non-coolant-through design means external flood or mist coolant is required for optimal life in deep or high-speed cuts.

Highlights

  • 135-degree split point starts on contact without walking
  • Cobalt steel with TiN coating resists heat and wear
  • Jobber length suits general-purpose drilling in metal
  • Size V (.3770 in) fits precise hole requirements
  • Heavy-duty construction handles tough materials cleanly

Specifications

BrandCHICAGO-LATROBE
TypeDrill Bits
MaterialHAWA

Questions about this item

Does the 135-degree split point on the 54121 cobalt bit reduce heat build-up during extended drilling?

The 135-degree split point is designed to start on contact and reduce walking, which helps manage heat during prolonged use in tough materials.

What chuck size is required to hold the .3770-inch shank of this jobber-length drill bit?

A standard 3/8-inch or 1/2-inch drill chuck will securely grip the .3770-inch diameter shank of this jobber-length bit.

Will the TiN coating on this cobalt bit wear quickly when used with older carbon-steel drill presses?

The TiN coating increases surface hardness and lubricity, extending bit life even on older machines with less precise spindle runout.

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