Chicago-latrobe 48746 Screw Machine Drill Bit 0.081 in Hss

Product Description

The CHICAGO-LATROBE 48746 is a screw machine length drill bit designed for high-speed steel general-purpose drilling in tight-clearance and short-reach applications. It measures 0.081 inches in diameter, corresponding to wire size 46, with a 118-degree standard point angle and a 1.75-inch overall length. The shortened flute and body of a screw machine length bit reduces deflection and provides better rigidity compared to jobber length bits. Two spiral flutes with a regular spiral pattern efficiently evacuate chips during drilling. A bright, uncoated finish keeps the surface close to base HSS hardness while avoiding coating costs for general-purpose work. Right-hand cut geometry suits standard drill press and hand-drill operation. This bit is used by machinists, pipefitters, fabricators, and maintenance technicians.

The 48746 is suited for drilling cast iron, non-ferrous metals, and steel in production and maintenance environments. Its screw machine length profile makes it a practical choice for drill press work, CNC turret applications, and hand drilling where stub-length rigidity is preferred over extended reach. The 0.081-inch diameter fills wire gauge drilling needs common in tapping operations, pilot holes, and precision through-hole work on metal stock. Diameter tolerance is held to plus 0.0000 and minus 0.0005 inches, supporting consistent hole quality for thread-prep and close-tolerance fitment. The Series 157 designation identifies this as part of a standardized Chicago-Latrobe lineup built to ISO standards.

Key Features

• Wire size 46 diameter at 0.081 inches with a tolerance of plus 0.0000 to minus 0.0005 inches for precise hole sizing
• 118-degree standard point angle with web-thinned, parallel web construction to reduce entry thrust
• High speed steel construction for general-purpose metal drilling across a wide hardness range
• Screw machine length body at 1.75 inches overall with a 0.75-inch flute length for improved rigidity and reduced deflection
• Bright, uncoated finish suitable for general-purpose cast iron, non-ferrous metal, and steel applications
• Straight-cylindrical shank compatible with standard drill chucks; right-hand cut for conventional rotation

Compatibility

Designed for use in standard drill presses, CNC turrets, and hand drills equipped with a chuck sized for a straight-cylindrical shank. Primary workpiece materials listed by the manufacturer are cast iron, non-ferrous metal, and steel.

Installation Notes

Secure the straight-cylindrical shank firmly in the drill chuck before operation to prevent slipping under cutting load. Use cutting fluid or coolant appropriate to the workpiece material when drilling steel to extend bit life, as this bit does not support internal coolant delivery. Inspect the point and cutting edges for wear or chipping before each use; a dull or damaged bit should be resharpened or replaced to maintain hole tolerance. Follow applicable shop safety standards and machine guarding requirements during drilling operations.