Osg 1171700 Straight Flute Tap 3/8-24 Unf Bottoming Hss

Product Description

The OSG 1171700 is a straight flute bottoming tap designed to cut 3/8-24 UNF internal threads in through-holes and blind holes where thread engagement must reach close to the bottom. Manufactured from high-speed steel with a bright uncoated finish, it carries a 3B class of fit and an H3 thread limit, delivering consistent tolerance control for standard fastener assemblies. With 3 straight flutes and a bottoming chamfer, it is suited for machinists and toolroom technicians running production or maintenance tapping operations on a range of common metals.

This tap is used in manual tapping, drill press, and CNC tapping applications where a bottoming chamfer is required to maximize thread depth in shallow blind holes. Its straight flute geometry is well-suited for shorter chipping materials. Compatible material applications include aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel, making it a versatile choice for general machining and maintenance repair work across manufacturing and industrial settings.

Key Features

• Bottoming chamfer for full thread depth in blind holes
• 3 straight flutes optimized for short-chipping materials including cast iron and steel
• High-speed steel construction for durability across a range of workpiece hardnesses
• 3B class of fit and H3 thread limit for standard tolerance internal threads
• Right-hand thread direction, 3/8-24 UNF thread form
• Bright uncoated finish suitable for use with cutting fluid

Compatibility

Designed for tapping 3/8-24 UNF threads in aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. Listed under OSG Series 103.

Installation Notes

Tapping operations should be performed by a qualified machinist following standard shop safety procedures. Ensure the workpiece is securely fixtured and the tap is properly aligned to the drilled hole before engagement to prevent tap breakage. Use an appropriate cutting fluid for the workpiece material to extend tool life and improve thread finish. When removing the tap from a blind hole, reverse direction carefully to avoid damaging the formed threads.