Osg 1590102 Straight Flute Tap 1/4-20 Unc Plug Hss

Product Description

The OSG 1590102 is a straight flute plug tap designed for cutting right-hand internal threads in a variety of ferrous and non-ferrous materials. It produces a 1/4-20 UNC thread profile with a plug chamfer, which provides a balance between starting ease and thread engagement length. The tap is manufactured from high-speed steel for durability under shop conditions. With 4 flutes and an H11 thread limit, it is suited for through-hole and open-blind-hole applications where chip evacuation is manageable along the flute length. Overall length is 2.5 inches and thread length is 1 inch.

This tap is intended for use in machine shop, maintenance, repair, and production environments where 1/4-20 UNC threads are required. It is compatible with ferrous and non-ferrous workpiece materials including aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel. The plug chamfer style makes it a general-purpose choice for most standard tapping operations. It is sold individually and sized for use in standard tap holders, tapping chucks, and CNC rigid-tap setups.

Key Features

• 1/4-20 UNC thread profile with right-hand thread direction
• Plug chamfer for general-purpose through-hole and open-blind-hole tapping
• 4 straight flutes for chip management in compatible materials
• H11 thread limit with 0.005 inch oversize designation for controlled fit
• High-speed steel construction for use across a broad range of workpiece materials
• Compact 2.5-inch overall length suits standard machine tap holders

Compatibility

Suitable for tapping aluminum, cast aluminum, cast iron, low-carbon steel, medium-carbon steel, and high-carbon steel workpieces. Designed for use in standard 1/4-inch tap holders and tapping chucks compatible with the OSG 101H series straight flute taps.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician using a properly aligned tap holder or tapping head. Ensure the workpiece is securely fixtured and the spindle is aligned to the hole axis before engaging the tap. Use an appropriate cutting fluid for the workpiece material to extend tool life and improve thread quality. Do not force the tap if resistance increases unexpectedly — back out to clear chips before continuing.