Cleveland C70297 Drill Bit Letter S 135 Point Hss

Product Description

The CLEVELAND C70297 is a screw machine length drill bit sized to letter S (0.3480 inches) and built from high-speed steel with a bright, uncoated finish. The 135-degree split point and web-thinned geometry reduce walking at entry and lower thrust force, making it well suited for production drilling where hole-start accuracy and cycle time matter. At 3-1/16 inches overall length, the stub-style body provides added rigidity compared to jobber-length bits, reducing deflection in short, high-rate drilling applications. Two spiral flutes with a regular helix clear chips efficiently. The straight-cylindrical shank seats directly in drill chucks or quick-change holders without adapters.

This bit is used in screw machine operations, CNC drilling, and manual drill press work where a short, stiff tool is preferred over jobber length. Primary workpiece materials include alloy steel and aluminum. The parallel web configuration and web thinning make it effective when drilling harder alloys that demand consistent point geometry and edge retention. Machinists, tool and die makers, and general metalworking shops will find this bit appropriate for high-volume hole production in those material groups.

Key Features

• Letter S size — 0.3480 inches diameter, tolerance +0.0000 to -0.0010 inches
• 135-degree split point with web thinning reduces walking and lowers required thrust
• Screw machine (stub) length at 3-1/16 inches OAL for increased rigidity
• High-speed steel construction handles alloy steel and aluminum workpieces
• Right-hand cut, straight-cylindrical shank fits standard drill chucks and holders
• Meets ASME B94.11M and NAS 907 Type C specifications

Compatibility

Designed as an OEM-style replacement or direct drop-in for screw machine length drill bits in letter S sizing; compatible with any drill chuck or quick-change holder accepting a 0.3480-inch straight-cylindrical shank.

Installation Notes

Installation and use should be performed by a qualified machinist or tool operator familiar with drill press, CNC, or screw machine setup. Secure the shank fully in the chuck or collet before operation and verify runout is within acceptable tolerance for the application. Inspect the cutting edges for wear or chipping before each use and replace the bit when point geometry degrades to avoid work hardening or oversized holes. Follow applicable shop safety standards including eye protection and proper workholding when drilling metal.