Cleveland C70282 Screw Machine Drill Bit Letter C Hss

Product Description

The CLEVELAND C70282 is a screw machine length drill bit sized to Letter C (0.2420 inches) with a 135-degree split point and a web-thinned tip geometry. Built from high-speed steel with a bright/uncoated finish, it is designed for high-volume drilling operations where a shorter flute length provides added rigidity and resistance to deflection. The right-hand cut, straight cylindrical shank seats securely in standard drill chucks and screw machine spindles. With an overall length of 2.5 inches and a flute length of 1.375 inches, this bit suits production environments where compact tooling reduces chatter and improves hole accuracy in ferrous and non-ferrous materials.

This bit is suited for drilling alloy steels and aluminum in both job-shop and production floor settings. The screw machine length (stub) configuration is the preferred choice when working in tight clearances or on automatic screw machines, CNC lathes, and drill presses where a full-length jobber bit would flex or chatter. The 135-degree split point reduces thrust force on entry, making it effective for starting without a center punch on flat stock. It conforms to ASME B94.11M and NAS 907 Type C specifications.

Key Features

• Letter C size — 0.2420 inches diameter with a tolerance of +0.0000 to -0.0007 inches for consistent hole sizing
• 135-degree split point with web thinning reduces entry thrust and eliminates the need for a center punch on most applications
• Screw machine (stub) length at 2.5 inches overall increases rigidity and minimizes deflection in production drilling
• High-speed steel construction rated for heavy-duty grade service in alloy steels and aluminum
• Bright/uncoated finish compatible with a wide range of cutting fluids without coating interaction
• Straight cylindrical shank fits standard 3-jaw chucks and collet systems without adapters

Compatibility

Designed for use in standard drill chucks, collet holders, and automatic screw machine spindles that accept a 0.2420-inch straight cylindrical shank. Conforms to ASME B94.11M and NAS 907 Type C specifications. Primary workpiece materials listed in the product data are alloy steel and aluminum.

Installation Notes

Install the shank fully into the chuck or collet and verify runout before beginning a production run. Secure the workpiece firmly to prevent movement during drilling. Use an appropriate cutting fluid for the workpiece material to extend tool life and maintain hole tolerance. Replace or resharpen the bit when thrust force increases noticeably or hole diameter drifts outside tolerance.