Osg 15159005 Cobalt Jobber Drill Bit No. 21 Tin

Product Description

The OSG 15159005 is a cobalt jobber-length drill bit in wire gauge size No. 21, with a decimal diameter of 0.1590 inches (4.04 mm). Finished with a Titanium Nitride (TiN) coating, it is built for high-performance drilling in steel and alloy steel. The 130-degree split point angle reduces walking and allows the bit to self-center on entry without a pilot hole. A right-hand spiral flute with R-thinned web geometry improves chip evacuation and reduces thrust in tough ferrous materials. Licensed tradespeople and machining professionals use this bit for production and maintenance drilling where tool longevity matters.

This bit is suited for drilling blind holes, cross holes, and through holes in steel and alloy steel workpieces. The straight-cylindrical shank with a 3/16-inch diameter fits standard drill chucks without an adapter. The Series 1500 designation places it in OSG's high-performance cobalt line, designed for applications where carbon steel or HSS tooling falls short — including hardened materials, stainless, and abrasion-resistant alloys. Typical install settings include CNC machining centers, drill presses, and hand-held electric drills in fabrication or maintenance environments.

Key Features

• Cobalt construction with TiN coating for extended tool life in ferrous and hard materials
• 130-degree drill point angle for reduced walking and self-centering entry
• R-thinned web reduces axial thrust and improves penetration in tough alloys
• Right-hand spiral flute with tapered web for efficient chip removal
• Straight-cylindrical shank fits standard 3-jaw chucks without modification
• Rated for blind hole, cross hole, and self-centering drilling applications

Compatibility

Designed as an OEM-style replacement or direct-fit jobber-length drill bit for applications requiring wire gauge No. 21 (0.1590 inches) diameter tooling in steel and alloy steel, classified under primary workpiece material code P.

Installation Notes

Install in a properly rated drill chuck and confirm the shank is fully seated before operation. Power down and de-energize all equipment before changing tooling. Use appropriate cutting fluid or coolant for extended runs in hard materials, even though this bit is not rated for coolant-through delivery. Follow applicable OSHA and shop-floor safety standards when operating rotary cutting tools.