Chicago-Latrobe
Chicago-Latrobe 49257 Screw Machine Drill Bit Z Size 135 Degrees Point .4130
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
- TypeDrill Bits
- 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.
Highlights
- 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
Specifications
| Brand | CHICAGO-LATROBE |
|---|---|
| Type | Drill Bits |
| Material | HAWA |
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.
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