Osg 1195100 Straight Flute Tap 1/4-20 Unc Hss Plug

Product Description

The OSG 1195100 is a straight flute tap designed for cutting 1/4-20 UNC internal threads in a wide range of metallic workpiece materials. Built from high-speed steel with a bright, uncoated finish, this tap features two flutes and a plug chamfer profile, making it well-suited for through-hole tapping applications where chips can evacuate ahead of the tool. The H3 thread limit holds a 3B class of fit, delivering the tolerance control required for standard fastener assemblies. Overall length is 2.5 inches, with a thread length of approximately 1 inch and a neck length of approximately 1.29 inches.

This tap is intended for use in machine shop, maintenance, and production environments where 1/4-20 UNC threads are common. The plug chamfer style requires a pre-existing hole that passes through the workpiece or provides sufficient chip clearance at the bottom. Suitable for use in manual tapping machines, CNC machining centers, and drill presses equipped with a tapping head. Coolant-through capability is not featured on this tap.

Key Features

• 1/4-20 UNC thread form with H3 thread limit for 3B class of fit tolerance
• Plug chamfer profile suited for through-hole tapping operations
• Two-flute geometry provides open chip flow in softer to medium-hardness materials
• High-speed steel construction offers durability across a broad range of workpiece materials
• Bright, uncoated finish is compatible with cutting oils and water-soluble coolants
• Right-hand thread direction for standard cutting orientation

Compatibility

Rated for use in aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel. Belongs to OSG Series 104.

Installation Notes

A licensed machinist or qualified maintenance technician should install this tap using a properly sized tap wrench, tapping head, or CNC rigid tapping cycle. Always ensure the workpiece is securely fixtured and the pilot hole is drilled to the correct tap drill diameter for a 1/4-20 UNC thread before beginning the tapping operation. Apply an appropriate cutting fluid for the workpiece material to extend tool life and improve thread quality. Inspect the tap for wear or chipping before each use and replace when thread quality degrades.