Chicago-latrobe 48729 Screw Machine Drill Bit 0.136 in

Product Description

The CHICAGO-LATROBE 48729 is a screw machine length drill bit designed for high-speed steel cutting in general-purpose drilling applications. At 0.136 inches in diameter, it corresponds to wire gauge size 29 and features a 118-degree standard point angle with a right-hand spiral flute. The shortened screw machine length body — 1-15/16 inches overall — provides added rigidity over jobber-length bits, reducing deflection in short-stroke drilling. The bright, uncoated HSS construction suits a wide range of workpiece materials without the added cost of coated tooling. This bit is a standard choice for machinists, tool and die shops, and trade professionals performing precision hole work.

This bit is rated for use in cast iron, non-ferrous metals, and steel. The screw machine length format makes it well-suited for drill press work, CNC turret operations, and any setup where a shorter, stiffer bit improves hole location accuracy. The straight-cylindrical shank is compatible with standard drill chucks and collets. Web-thinned construction reduces thrust requirements at the cutting point, which is particularly useful when drilling harder ferrous materials. Series 157 represents a general-purpose grade intended for everyday production and maintenance drilling tasks.

Key Features

• 0.136 inch diameter, wire size 29 — precise sizing for close-tolerance hole requirements
• 118-degree standard point angle with web-thinned tip for reduced thrust and cleaner entry
• Screw machine length (1-15/16 inches overall) for improved rigidity and reduced deflection
• High speed steel construction, bright/uncoated finish — suitable for cast iron, non-ferrous metals, and steel
• Right-hand cut, regular spiral, two-flute design for efficient chip evacuation
• Straight-cylindrical shank fits standard drill chucks and collets without adapters

Compatibility

Designed as a general-purpose screw machine length drill bit compatible with standard drill chucks and collets accepting a straight-cylindrical shank. Suitable for drilling cast iron, non-ferrous metals, and steel workpieces across production and maintenance applications.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or trade professionals familiar with rotary cutting tools. Secure the straight-cylindrical shank firmly in the chuck or collet before operation and verify runout is within acceptable limits. Always wear appropriate eye protection and secure the workpiece before drilling. Follow the machine manufacturer's recommended RPM and feed rate guidelines for the workpiece material and bit diameter.