Osg 220-3970 Solid Carbide Jobber Drill Bit Letter X

Product Description

The OSG 220-3970 is a solid carbide jobber-length drill bit sized to Letter X (0.3970 inch / 10.08 mm) and built for production drilling in ferrous and non-ferrous materials. It features a 118-degree web-thinned point that reduces thrust and promotes self-centering entry, a regular spiral flute for chip evacuation, and a bright uncoated finish suited for dry or flood-coolant setups. Overall length is 4.5 inches with a 2.875-inch flute length. The straight-cylindrical shank fits standard drill chucks without adapters. This bit is part of OSG Series 220D and is classified as a general-purpose tool intended for professional machining environments.

The 220-3970 is designed for blind hole drilling, cross-hole drilling, through-hole drilling, and self-centering applications. Primary workpiece materials include steel, alloy steel, stainless steel, cast iron, aluminum, aluminum alloy, and aluminum silicate. It is appropriate for use in manual and CNC drilling setups where consistent diameter tolerance and chip control are required. Diameter tolerance is held to +0 to -0.013 mm, making it suitable for close-tolerance holes in production and maintenance machining work.

Key Features

• Solid carbide construction for rigidity and wear resistance in hard materials
• Web-thinned 118-degree point reduces entry thrust and supports self-centering
• Regular spiral flute design promotes efficient chip evacuation
• Bright uncoated finish compatible with a range of cutting fluids and dry cutting
• Straight-cylindrical shank fits standard drill chucks without sleeves or adapters
• Tight diameter tolerance (+0 to -0.013 mm) for consistent, repeatable hole sizing

Compatibility

Designed as a general-purpose replacement or production drill bit for applications requiring Letter X sizing (0.3970 inch) in steel, stainless steel, cast iron, aluminum, and aluminum alloy workpieces across OSG Series 220D specifications.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians familiar with carbide drill bit handling. Secure the straight-cylindrical shank fully in a drill chuck or collet before operation and verify runout before cutting. Carbide tooling is brittle — avoid lateral loading, interrupted cuts without proper feed rate adjustments, or dropping the bit on hard surfaces. Follow shop safety standards and machine manufacturer guidelines for spindle speed and feed rate selection.