Osg 1144900 Straight Flute Tap 3/4-10 Unc Plug Hss

Product Description

The OSG 1144900 is a straight flute plug tap designed for cutting 3/4-10 UNC internal threads in a wide range of metals. Built from high-speed steel with a bright, uncoated finish, it delivers reliable thread cutting performance in production and maintenance applications. The tap features 4 flutes and a plug chamfer, providing a balance between ease of starting and thread engagement depth. With an overall length of 4.25 inches and a 2-inch thread length, it fits standard tap holders and machine spindles. The H5 thread limit ensures consistent class 2B and 3B fit tolerances across the threaded hole.

This tap is suited for threading operations in ferrous and non-ferrous materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. It is used in both manual tapping and machine tapping setups where a through-hole or open-bottomed blind hole allows chip evacuation along the straight flutes. Machinists, tool and die makers, and maintenance technicians will find it appropriate for general-purpose production work in shops running standard UNC fastener specifications.

Key Features

• 3/4-10 UNC thread size with right-hand thread direction
• 4 straight flutes with plug chamfer for balanced starting and cutting
• H5 thread limit for 2B and 3B class of fit tolerances
• High-speed steel construction suitable for a broad range of metals
• Bright, uncoated finish - compatible with standard cutting fluids
• No coolant-through design; standard external coolant application applies

Compatibility

Designed as an OEM-style straight flute tap for use in standard 3/4-10 UNC threading applications across aluminum, cast iron, and carbon steel workpieces. Compatible with material applications including aluminum, cast aluminum, cast iron, high-carbon steel, low-carbon steel, and medium-carbon steel as specified by OSG Series 101.

Installation Notes

This tap is installed by machinists and maintenance technicians using a standard tap wrench, tapping head, or CNC machine spindle with appropriate tap holder. Secure the workpiece firmly and ensure the hole is drilled to the correct tap drill size for 3/4-10 UNC before beginning the threading operation. Straight flute taps require adequate chip clearance; use in through-holes or shallow blind holes where chips can exit freely. Apply a suitable cutting fluid for the workpiece material to extend tool life and improve thread finish.