Cleveland C70299 Drill Bit Letter U 0.3680 in Hss 135 Pt

Product Description

The CLEVELAND C70299 is a screw machine length drill bit sized to Letter U (0.3680 inches) and built from heavy-duty high-speed steel with a bright, uncoated finish. The 135-degree split point reduces walking at entry and lowers thrust, making it well suited to production drilling and tight-clearance work where a jobber-length bit would be impractical. The shortened overall length of 3-1/8 inches adds rigidity and reduces deflection in drill press, turret lathe, and screw machine applications. Two spiral flutes with a web-thinned, parallel web configuration promote chip evacuation during through-hole operations. Right-hand cutting direction. Manufactured to ASME B94.11M and NAS 907 Type C specifications.

This bit is intended for drilling alloy steels and aluminum in production and maintenance environments. The screw machine length profile is a standard choice when working inside chucks, turrets, or fixtures where reduced stick-out matters. Its 0.3680-inch straight-cylindrical shank seats directly in standard collets and drill chucks without adapters. Licensed HVAC, plumbing, and mechanical trades also use screw machine length bits for in-place work on equipment frames and panels where clearance is limited. Sold individually.

Key Features

• Letter U size — 0.3680 inches diameter with a tight tolerance of +0.0000 to -0.0010 inches
• 135-degree split point minimizes walking and reduces entry thrust
• Web-thinned parallel web improves chip flow and reduces heat buildup
• Screw machine (stub) length — 3-1/8 inches OAL — adds rigidity and suits close-clearance drilling
• Heavy-duty high-speed steel construction for use in alloy steel and aluminum
• Meets ASME B94.11M and NAS 907 Type C standards

Compatibility

Designed as an OEM-style replacement or direct-fit screw machine length drill bit for use in standard drill chucks and collets accepting a 0.3680-inch straight-cylindrical shank. Primary workpiece materials listed by the manufacturer are alloy steel and aluminum.

Installation Notes

Secure the shank fully in the chuck or collet before operation and verify runout is within acceptable limits for the application. Power down and lock out the machine before changing bits. Use appropriate cutting fluid for alloy steel applications to extend tool life and manage heat. Follow applicable shop safety standards and machine manufacturer guidelines for speed and feed selection.