Chicago-latrobe 44998 Cobalt Jobber Drill Bit No. 28

Product Description

The CHICAGO-LATROBE 44998 is a cobalt jobber-length drill bit in wire gauge size No. 28 (0.1405 inches decimal), designed for high-performance drilling in hard and abrasive materials. Built from M42 cobalt high-speed steel and finished with a TiAlN coating, this bit handles elevated cutting temperatures without premature wear. The 135-degree split point reduces walking and thrust load at the start of a cut. Overall length is 2-7/8 inches with a flute length of 1-3/4 inches. It is part of the Series 550TA line and conforms to DIN 338 and NAS 907 Type J standards. Licensed HVAC technicians, machinists, and maintenance trades use this bit for precision drilling in aerospace-grade and hard-alloy workpieces.

This bit is engineered specifically for drilling titanium and other difficult-to-machine metals common in aerospace, industrial maintenance, and high-spec mechanical work. The regular spiral flute with web-thinned, tapered web geometry clears chips efficiently in deep-hole applications. The straight-cylindrical shank seats securely in standard drill chucks without slippage. The TiAlN coating extends tool life significantly when drilling work-hardening materials at higher surface speeds compared to uncoated tooling. This is a single-piece unit sold individually.

Key Features

• M42 cobalt high-speed steel construction for heat and wear resistance in hard-metal drilling
• TiAlN coating improves surface hardness and thermal barrier for extended tool life
• 135-degree split point reduces thrust and eliminates center-punch requirement on most setups
• Web-thinned tapered web improves chip evacuation and reduces torque demand
• Meets DIN 338 and NAS 907 Type J standards for dimensional and performance conformance
• Right-hand cut, regular spiral flute, straight-cylindrical shank for broad chuck compatibility

Compatibility

Designed as an OEM-style jobber-length drill bit for use in standard drill chucks accepting a 0.1405-inch straight-cylindrical shank. Primary workpiece material is titanium per NAS 907 specification, but the M42 cobalt construction and TiAlN coating make this bit suitable for other hard and work-hardening alloys in similar decimal-inch size ranges (0.1000 to 0.1500 inches).

Installation Notes

Install into a compatible drill chuck and tighten securely before operation. Machinists and maintenance trades should verify spindle speed and feed rate against published cutting data for the workpiece material before drilling. Use appropriate cutting fluid or coolant when drilling titanium and hard alloys to manage heat buildup, as this bit does not support through-coolant delivery. Inspect the cutting edges before each use and replace if chipping or excessive wear is observed.