Chicago-latrobe 47716 Cobalt Drill Bit Letter E 1/4 in

Product Description

The CHICAGO-LATROBE 47716 is a cobalt jobber length drill bit sized at Letter E (0.2500 inches), designed for high-performance drilling in hard and abrasive materials. Built to Series 550ASP specifications and conforming to NAS 907 Type B standards, this bit features a 135-degree split point for fast penetration and reduced walking on entry. The gold finish indicates cobalt steel construction, which sustains cutting edge integrity at elevated temperatures. With a straight-cylindrical shank at 0.2500 inches and an overall length of 4.0000 inches, it fits standard drill chucks and CNC setups without adapters. Intended for installation by machinists, maintenance technicians, and trade professionals working in demanding production or field environments.

This bit is rated for drilling titanium as its primary workpiece material, making it well-suited for aerospace, mechanical, and industrial maintenance applications where high-speed steel bits fail prematurely. The regular spiral flute with a 2.7500-inch flute length promotes efficient chip evacuation during deep-hole drilling. A tapered web configuration with web thinning reduces thrust requirements and improves center cutting performance. Right-hand cutting direction is standard for conventional drill press, hand drill, and CNC spindle use.

Key Features

• Cobalt steel construction with gold finish for heat resistance in hard-material drilling
• 135-degree split point reduces drill walking and lowers entry thrust
• Web-thinned, tapered web improves center cutting and reduces feed force
• Straight-cylindrical shank at 0.2500 inches fits standard chucks without adapters
• Meets NAS 907 Type B specification for heavy-duty industrial use
• Regular spiral flute with 2.7500-inch flute length for reliable chip clearance

Compatibility

Designed as a heavy-duty OEM-style replacement or direct-use jobber drill bit for industrial and trade applications requiring a Letter E (0.2500-inch) diameter cobalt bit conforming to NAS 907 Type B standards. Primary workpiece material is titanium; also appropriate for stainless steel and other hard alloys where cobalt tooling is specified.

Installation Notes

This bit is installed by machinists, maintenance technicians, and trade professionals using standard drill presses, hand drills, or CNC machining centers. Secure the straight-cylindrical shank firmly in a keyed or keyless chuck before operation. Coolant-through is not supported; use appropriate external cutting fluid when drilling titanium or hardened alloys to extend tool life. Inspect the cutting edges before each use and replace the bit if chipping or wear is detected at the split point.