Chicago-latrobe 49089 Screw Machine Drill Bit 0.166 in Hss

Product Description

The CHICAGO-LATROBE 49089 is a screw machine length drill bit designed for general-purpose drilling in a wide range of materials. Built from high speed steel with a bright, uncoated finish, this bit features a left-hand spiral flute configuration and a standard 118-degree split point. The shorter screw machine length body provides added rigidity compared to jobber-length bits, reducing deflection in production and machine-tool environments. With a wire gauge size of No. 19 and a decimal diameter of 0.1660 inches, it fits standard straight-cylindrical chucks and collets. Web-thinned geometry lowers the thrust force required at entry and helps maintain accuracy across repeated cycles.

This bit is suited for use in drill presses, CNC machining centers, screw machines, and manual lathes where a short, stiff bit profile is preferred. Primary workpiece materials include aluminum, copper, magnesium, slate, thermoplastic, and wood. The left-hand cut direction makes it well suited for removing broken fasteners or reverse-threading operations. It is a single-piece unit sold individually and fits within the 0.1500 to 0.2000 inch diameter range of the Series 157L line.

Key Features

• Left-hand spiral flute cut for reverse-rotation drilling and broken fastener extraction
• 118-degree standard point angle with web-thinned tip for reduced entry thrust
• High speed steel construction for general-purpose durability across multiple materials
• Screw machine length body provides increased rigidity and reduced deflection
• Straight-cylindrical shank fits standard drill chucks and collets without adapters
• Manufactured to ISO standards with a diameter tolerance of +0.0000 to -0.0007 inches

Compatibility

Designed as a general-purpose replacement or production-use drill bit for applications requiring a No. 19 wire gauge, 0.1660-inch diameter, left-hand cut screw machine length bit in aluminum, copper, magnesium, slate, thermoplastic, or wood workpieces.

Installation Notes

Installation is performed by machinists and tool-and-die or maintenance technicians operating drill presses, lathes, or CNC equipment. Secure the straight-cylindrical shank fully in the chuck or collet before operation and confirm the spindle rotation direction matches the left-hand cut orientation of the bit. Inspect the cutting edges and web condition before each use; discard or resharpen if chipping or dulling is present. Follow applicable shop safety and machine guarding standards when operating rotating tooling.