Cleveland C70301 Drill Bit Letter W 0.386 in Hss 135 Pt

Product Description

The CLEVELAND C70301 is a screw machine length drill bit sized at Letter W (0.3860 inches decimal equivalent) and built from heavy-duty high-speed steel with a bright, uncoated finish. The 135-degree split point geometry reduces walking at entry and lowers the thrust required to start the cut, making it well suited for production drilling in alloy steels and aluminum. The web-thinned, parallel-web configuration keeps the cutting edge aggressive through the full depth of the hole. At 3.25 inches overall length, this stub-style bit fits standard drill chucks without requiring extended reach setups. The straight-cylindrical shank measures 0.3860 inches in diameter with a 1.375-inch shank length, giving solid grip in both keyed and keyless chucks. This bit is manufactured to ASME B94.11M and meets NAS 907 Type C specification.

Screw machine length drill bits are a standard choice in production machining, job-shop environments, and maintenance repair operations where rigidity and accuracy matter more than depth reach. The C70301 is appropriate for hand-held drill use, drill press work, and CNC setups requiring a compact, high-stiffness bit. Primary workpiece materials include alloy steel and aluminum. The shorter flute length of 1.875 inches limits deflection in interrupted cuts and thin-wall applications. This bit is sold individually and is suitable for machinists, millwrights, and industrial maintenance technicians working in metal fabrication or general manufacturing.

Key Features

• Letter W size — 0.3860 inches decimal equivalent, tolerance +0.0000 to -0.0010 inches
• 135-degree split point reduces entry walking and lowers drilling thrust
• Heavy-duty high-speed steel construction for alloy steel and aluminum applications
• Web-thinned, parallel-web design maintains cutting efficiency at full depth
• Screw machine (stub) length — 3.25 inches OAL — maximizes rigidity and minimizes deflection
• Meets ASME B94.11M and NAS 907 Type C specification

Compatibility

Designed as an OEM-style replacement or production-supply drill bit for applications in alloy steel and aluminum workpieces requiring a Letter W, screw machine length drill with a straight-cylindrical shank.

Installation Notes

Secure the straight-cylindrical shank firmly in a keyed or keyless chuck before use. Ensure the drill press or handheld drill is powered off and triggers are locked out before changing or inspecting the bit. Use appropriate cutting fluid for alloy steel applications to extend tool life and maintain hole tolerance. Inspect the split point for wear or chipping between uses, as a damaged point will increase entry deflection and degrade hole quality.