Chicago-Latrobe
Chicago-Latrobe 40582 Extension Drill 3/8 x 12 in HSS Black Oxide
Extra-long 12 in HSS drill bit with 135-degree split point and black-oxide finish for deep drilling
- TypeDrill Bits
- MaterialHAWA
- Extra reach with 12 in overall length
- Clean starts from 135° split point
- Hard-wearing HSS construction resists wear
- Black oxide finish reduces friction and corrosion
- 28° helix clears chips efficiently
Chicago-Latrobe 40582 Extension Drill
The Chicago-Latrobe 40582 is a high-speed steel extension drill bit designed for machinists and maintenance technicians who need to reach deep or obstructed holes. Its 12-inch overall length provides the necessary reach for through-hole applications in metal components.
Black Oxide Finish and Split Point
The black oxide surface treatment reduces friction and resists corrosion during extended use in steel and alloy materials. A 135-degree split point ensures accurate starting without centre punching and minimises bit wander on curved or angled surfaces.
3/8 Inch Diameter with 1-1/2 Inch Drilling Depth
This fractional-inch bit cuts a precise 3/8-inch hole with a maximum drilling depth of 1-1/2 inches per pass. The 4xD length-to-diameter ratio suits short-chip materials but limits use in deep-hole drilling beyond the stated depth capacity.
Highlights
- Extra reach with 12 in overall length
- Clean starts from 135° split point
- Hard-wearing HSS construction resists wear
- Black oxide finish reduces friction and corrosion
- 28° helix clears chips efficiently
Specifications
| Brand | CHICAGO-LATROBE |
|---|---|
| Type | Drill Bits |
| Material | HAWA |
Questions about this item
When will the 135-degree split point on the 40582 need resharpening?
The high-speed steel tip stays sharp through repeated drilling; resharpen when hole quality drops or feed pressure rises noticeably.
What stops a continuous cut with the 12-inch flute length?
The 1-1/2-inch maximum drilling depth limits each plunge; chips must be cleared before the next pass.
How hot does the black-oxide 40582 get during all-day drilling?
Black oxide reduces friction heat; expect warm but manageable temperatures with proper cutting fluid and peck cycles.
Also in this aisle
People compared these
Same shelf, same checkout — eight coins and a 30-minute rate lock.



