Osg 1172000 Straight Flute Bottoming Tap 7/16-14 Unc

Product Description

The OSG 1172000 is a straight flute bottoming tap designed to cut right-hand internal threads in through-holes and blind holes where threads must extend close to the bottom. Built from high-speed steel with a bright, uncoated finish, it cuts a 7/16-14 UNC thread form with three flutes and an H3 thread limit tolerance. Overall length is 3-5/32 inches with a thread length of 1-7/16 inches and a shank diameter of 0.323 inches. Machinists, toolroom technicians, and maintenance mechanics use this tap in manual tap handles, CNC tapping heads, and drill press setups wherever a clean bottoming thread is required.

This tap is suited for general metalworking and maintenance applications in both production and job-shop environments. The bottoming chamfer allows thread engagement very close to the bottom of a blind hole, making it the correct choice when a plug or taper tap has already started the thread and full depth is needed. It performs in a range of workpiece materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel.

Key Features

• Bottoming chamfer allows threading to near the bottom of blind holes
• High-speed steel construction provides durability across ferrous and non-ferrous materials
• H3 thread limit tolerance suits standard fit classes for UNC threads
• Three straight flutes support chip clearance in shorter-chipping materials
• Bright, uncoated finish maintains as-ground cutting geometry without added coating thickness
• Right-hand thread direction compatible with standard tapping equipment

Compatibility

Designed for use in standard tap handles, tap wrenches, and machine tapping heads accepting a straight-shank tap with a 0.323-inch shank diameter. Compatible with workpiece materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel per OSG Series 103 specifications.

Installation Notes

This tap should be installed and operated by qualified machinists or toolroom technicians familiar with tapping procedures. Always ensure the workpiece is securely clamped and properly aligned before starting the tap to prevent breakage. Apply cutting fluid appropriate to the workpiece material to extend tool life and improve thread finish. When tapping blind holes, use a plug or taper tap first to establish the thread, then follow with this bottoming tap to extend threads to full depth.