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
Chicago-Latrobe 49257 Z-size drill bit, black oxide finish, 135-degree split point

Chicago-Latrobe

Chicago-Latrobe 49257 Screw Machine Drill Bit Z Size 135 Degrees Point .4130

SKU CH-JF5G-71G5E

Screw machine drill bit in Z size with a 135-degree split point, high-speed steel construction, black oxide finish and 0.4130 decimal equivalent

  • Product typeDrill Bits
  • Main materialHAWA
  • Z-size precision for tight-tolerance holes
  • 135-degree split point starts cleanly without wandering
  • High-speed steel resists wear in production runs
  • Black oxide finish reduces friction and heat build-up
  • Right-hand cutting matches standard machine rotation

Chicago-Latrobe 49257 Z-size drill bit

The Chicago-Latrobe 49257 is a screw-machine drill bit in Z size with a decimal equivalent of .4130. It is made from high-speed steel with a black oxide finish and features a 135-degree split point for self-centering. The right-hand cutting direction suits standard drilling operations in metalworking shops and maintenance departments.

Sustained drilling performance

The high-speed steel construction maintains hardness during extended drilling cycles in steel and alloy workpieces. The 135-degree split point reduces thrust load and minimises walk at the start of each hole. Black oxide surface treatment helps retain lubricant and resists chip welding during repetitive production runs.

Heat wear and power draw

Black oxide finish improves heat dissipation and reduces friction when drilling without coolant. The split point geometry lowers cutting forces, which decreases power demand on the drill motor during continuous use. Right-hand spiral clears chips efficiently, limiting heat buildup in the cutting zone.

How it compares

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

Price $7.99
Cheaper than about 91% 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

How much heat does the 135-degree split point generate during extended drilling sessions?

The 135-degree split point design reduces thrust force and heat buildup by centering the bit without a pilot hole, while the high-speed steel construction maintains hardness at elevated temperatures common in screw machine operations.

What collet or chuck size is required to hold the .4130 diameter shank?

A standard 1/2-inch or 13 mm drill chuck with three-jaw clamping will securely grip the .4130-inch shank, which is typical for screw machine length bits used in bench drills, lathes, or CNC tool holders.

Will the black oxide finish and right-hand cut work with older high-speed steel tooling setups?

Yes, the black oxide surface treatment reduces galling and improves chip flow in legacy equipment, while the right-hand cutting direction matches conventional drill presses, turret lathes, and manual milling machines.

More in Bits, Hole Saws & Accessory Kits

Similar items