Osg 61539 Screw Machine Drill Bit 3.90 Mm Tin Hss

Product Description

The OSG 61539 is a screw machine length drill bit designed for high-performance drilling in metalworking and industrial applications. Built from high-speed steel with a titanium nitride (TiN) coating, it delivers extended tool life and reduced friction during cutting. The bit measures 3.90 mm in diameter with a 54 mm overall length, making it well-suited for short-hole drilling where rigidity and accuracy matter. The 130-degree faceted point geometry reduces thrust and improves chip evacuation on entry. Web thinning further lowers cutting resistance, particularly when drilling harder alloys. Licensed machinists, toolmakers, and maintenance mechanics are the primary installers and users of this bit.

This drill bit is intended for use in screw machines, CNC machining centers, drill presses, and hand-held power tools where a straight-cylindrical shank is compatible. It is suited for drilling steel, stainless steel, aluminum, aluminum alloy, and aluminum silicate workpieces. The short screw machine length provides greater stability and reduced deflection compared to jobber-length bits, making it a preferred choice in production drilling environments where hole position tolerance is critical.

Key Features

• TiN coating increases surface hardness and extends tool life on ferrous and non-ferrous materials
• 130-degree faceted point angle reduces walking and improves entry accuracy on flat and curved surfaces
• Web-thinned, tapered web configuration lowers thrust and improves chip flow
• Screw machine length body provides superior rigidity and minimizes deflection in deep setups
• Right-hand spiral flute with regular helix efficiently clears chips from the cut zone
• Straight-cylindrical shank at 4.00 mm diameter fits standard collets and drill chucks without modification

Compatibility

Compatible with steel, stainless steel, aluminum, aluminum alloy, and aluminum silicate workpieces. Fits standard drill chucks and collet systems accepting a 4.00 mm straight-cylindrical shank. Part of the OSG Series 1100 high-performance drill line.

Installation Notes

This bit is installed and operated by machinists and maintenance mechanics using screw machines, CNC drilling centers, or manual drill presses. Secure the shank fully in the chuck or collet before operation and verify runout is within acceptable tolerance before drilling production parts. Use appropriate cutting fluid or coolant for steel and stainless steel applications to maintain cutting edge integrity. Inspect the cutting edge for wear or chipping before each use and replace the bit if the TiN coating is fully worn through at the cutting edge.