Cleveland C70287 Drill Bit Letter I 135 Point Hss

Product Description

The CLEVELAND C70287 is a screw machine length drill bit sized at Letter I (0.2720 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 heavy-duty drilling in production and fabrication environments. The short overall length of 2-11/16 inches provides added rigidity compared to jobber-length bits, reducing deflection in tight setups. Two spiral flutes with a regular helix evacuate chips efficiently. This bit is used by machinists, millwrights, and tool-room technicians working on repetitive hole-making operations.

The C70287 is suited for drilling alloy steel and aluminum in screw machine, CNC, and manual drill press applications. Its parallel web configuration and web-thinned point reduce thrust requirements at entry, making it a practical choice for production runs where cycle time and tool life matter. The straight cylindrical shank fits standard drill chucks and collet holders without modification. The 1-1/2 inch flute length handles typical stock thicknesses encountered in machined-component production work.

Key Features

• Letter I size — 0.2720 inches diameter with a diameter tolerance of +0.0000 to -0.0010 inches
• 135-degree split point with web-thinned, parallel web construction reduces entry thrust
• High-speed steel construction rated for heavy-duty service
• Screw machine (stub) length at 2-11/16 inches OAL for improved rigidity in close-clearance setups
• Right-hand cutting direction with regular spiral flutes for reliable chip evacuation
• Meets ASME B94.11M and NAS 907 Type C specifications

Compatibility

Designed as an OEM-style replacement or direct-use screw machine drill bit for standard drill chucks and collet systems accepting a 0.2720-inch straight cylindrical shank. Primary workpiece materials listed are alloy steel and aluminum.

Installation Notes

Installation of this bit is performed by machinists and tool-room technicians using a drill press, CNC machining center, or screw machine equipped with a compatible chuck or collet. Secure the shank fully within the chuck or collet to the manufacturer-specified engagement depth before operating. Ensure spindle speed and feed rate are appropriate for the workpiece material and bit diameter per standard machining data references. Inspect the cutting edges for wear before each use and replace the bit when point geometry degrades to avoid workpiece damage or bit breakage.