Chicago-latrobe 48242 Screw Machine Drill Bit 0.281 in

Product Description

The CHICAGO-LATROBE 48242 is a screw machine length drill bit designed for high-production drilling in cast iron and steel. Built from high speed steel (HSS) with a coated finish, it features a 135-degree split point that reduces walking and allows the bit to start cutting immediately without center-punching. The parallel web construction and web-thinned geometry reduce thrust requirements and keep the cutting action efficient during heavy-duty applications. At 0.281 inches (9/32 inch) in diameter and 2-11/16 inches overall length, the stub-style body provides extra rigidity compared to jobber-length bits, making it well-suited for drill press and CNC work where deflection must be minimized.

This bit fits standard production and maintenance drilling operations in metalworking environments, including fabrication shops, machine shops, and industrial maintenance settings. The screw machine length format is common in CNC turret and gang-drilling setups where a shorter, stiffer bit reduces chatter and improves hole tolerance. Primary workpiece materials include cast iron and steel. Series 2159 is Chicago-Latrobe's heavy-duty stub-length line, manufactured to NAS 907 and ISO standards for consistent dimensional accuracy across production runs.

Key Features

• 135-degree split point reduces thrust and eliminates center-punch requirement on steel and cast iron
• Web-thinned, parallel web design lowers cutting resistance during heavy-duty drilling
• Screw machine (stub) length body at 2-11/16 inches overall provides superior rigidity over jobber-length bits
• High speed steel construction with coated finish for extended tool life
• Right-hand cut with 2-flute regular spiral for efficient chip evacuation
• Manufactured to NAS 907 and ISO standards with tight diameter tolerance of +0.0000 to -0.0010 inches

Compatibility

Designed for use in standard straight-shank drill chucks on drill presses, CNC turret machines, and hand drills. Primary workpiece materials are cast iron and steel. Fits within the 0.2500 to 0.3000 inch drill bit size range of the Series 2159 product family.

Installation Notes

A licensed machinist or trained maintenance technician should secure the straight-cylindrical shank firmly in a keyed or keyless chuck before operation. Ensure the workpiece is clamped and the machine is at a full stop before bit changes. Use appropriate cutting fluid or coolant on the workpiece surface when drilling steel to reduce heat buildup, as this bit does not support coolant-through delivery. Inspect the split point for chipping or wear before each use, as a damaged point will reduce hole accuracy and increase thrust load on the spindle.