Chicago-latrobe 49086 Screw Machine Drill Bit No. 16

Product Description

The CHICAGO-LATROBE 49086 is a screw machine length drill bit designed for left-hand cutting in general-purpose drilling applications. Built from high-speed steel with a bright/uncoated finish, it carries a No. 16 wire gauge designation and measures 0.1770 inches in diameter. The 118-degree standard point angle and web-thinned geometry reduce entry resistance and improve chip clearance. At 2.1875 inches overall length with a 1.0625-inch straight-cylindrical shank, this stub-length bit is well suited for close-tolerance work in drill presses and screw machine setups where rigidity and minimal runout are critical.

This bit is intended for drilling non-ferrous metals and softer materials including aluminum, copper, magnesium, slate, thermoplastic, and wood. The left-hand cut makes it particularly useful for backing out broken fasteners and reverse-extracting damaged studs without additional tooling. Machinists, maintenance technicians, and tool-and-die professionals will find this bit appropriate for production and repair environments where short overall length reduces chatter and deflection.

Key Features

• Left-hand cutting direction for reverse-drilling and broken fastener extraction
• No. 16 wire size, 0.1770-inch diameter with tight tolerance of +0.0000 to -0.0007 inches
• 118-degree standard point angle with web-thinned, parallel-web construction
• High-speed steel construction with bright/uncoated finish for general-purpose use
• Screw machine (stub) length at 2.1875 inches OAL for maximum rigidity
• 2-flute regular spiral with straight-cylindrical shank for standard chuck compatibility

Compatibility

Designed for use with standard drill chucks and screw machine setups accepting a 0.1770-inch straight-cylindrical shank. Suitable for drilling aluminum, copper, magnesium, slate, thermoplastic, and wood per the manufacturer specifications for the Series 157L line.

Installation Notes

Installation and use should be performed by qualified machinists or maintenance technicians familiar with drill press, lathe, or screw machine operation. Secure the shank fully in the chuck before operation and verify zero runout before engaging the workpiece. Left-hand bits rotate in the opposite direction of standard bits; confirm spindle direction before use. Follow applicable shop safety procedures including eye protection and proper workholding.