Chicago-latrobe 49403 No. 33 Screw Machine Drill Bit Hss

Product Description

The CHICAGO-LATROBE 49403 is a screw machine length drill bit designed for fast, accurate drilling in ferrous metals and cast iron. It carries a No. 33 wire gauge designation, corresponding to a decimal diameter of 0.1130 inches. The 135-degree split point geometry self-centers on contact, reducing the need for a center punch and minimizing walking on hard surfaces. The parallel web construction and web-thinned tip lower cutting resistance and help control chip formation. Built from heavy-duty high-speed steel with a coated finish, this bit is suited for production environments where tool life and hole quality matter. Licensed machinists, tool-and-die shops, and maintenance mechanics are the primary users.

The 49403 is a screw machine length bit, meaning it runs shorter than a jobber bit. That reduced length adds rigidity and improves accuracy in close-tolerance applications. It is well suited for drilling into cast iron, carbon steel, and alloy steel in machine tool setups, turret lathes, and CNC drill presses. The right-hand spiral flutes evacuate chips efficiently in through-hole and blind-hole operations. The straight cylindrical shank fits standard drill chucks and collet systems without modification.

Key Features

• No. 33 wire gauge size, 0.1130 inches decimal diameter with a tight tolerance of +0.0000 to -0.0005 inches
• 135-degree split point with web thinning for self-centering entry and reduced thrust force
• Screw machine length body for increased rigidity compared to jobber-length bits
• Heavy-duty high-speed steel construction rated for cast iron and steel workpieces
• 2-flute regular spiral design with straight cylindrical shank for broad chuck compatibility
• Meets NAS 907 specification and ISO standards

Compatibility

Designed as a Series 159 screw machine length drill bit compatible with standard drill chucks and collet holders accepting a 0.1130-inch straight cylindrical shank. Intended for use on cast iron and steel workpieces per the manufacturer specification.

Installation Notes

Install in a properly rated drill chuck or collet and verify shank seating before operation. Power down and lock out the machine spindle before changing or inspecting tooling. Do not exceed the spindle speed recommended for the workpiece material and bit diameter. Secure the workpiece firmly to prevent movement during drilling.