Guhring 9039810095250 Spiral Flute Tap 3/8-24 Unc Cobalt Tin

Product Description

The GUHRING 9039810095250 is a spiral flute tap designed for blind hole threading in alloyed and unalloyed steel. Part of the Series 3981 line, it cuts a 3/8-24 UNC right-hand thread using three fast-helix flutes set at a 40-degree helix angle. The TiN (titanium nitride) coating reduces friction and extends tool life in ferrous materials. Built from cobalt high-speed steel, the tap handles the heat and hardness demands of alloy steel tapping where standard HSS tooling wears prematurely. The H7 thread limit provides a slightly oversize thread (0.003 inches over nominal) to account for springback and achieve a proper class-of-fit in steel. Overall length is 2.941 inches.

This tap is suited for production and maintenance machining operations requiring accurate blind hole threads in steel workpieces. The modified bottoming chamfer allows threading close to the bottom of a blind hole while still providing enough lead to start the tap cleanly. The fast spiral flute geometry evacuates chips up and out of the hole, reducing the risk of chip packing in deep or tight blind hole applications. It is appropriate for use in CNC machining centers, manual knee mills, and drill press setups where controlled tapping is performed.

Key Features

• Cobalt HSS construction for elevated heat and wear resistance in alloy steel
• TiN coating reduces friction and extends tool life in ferrous materials
• 40-degree fast helix flute angle promotes efficient chip evacuation in blind holes
• Modified bottoming chamfer enables threading close to the bottom of blind holes
• H7 thread limit with 0.003 inches oversize compensates for material springback
• Right-hand flute and right-hand thread configuration for standard tapping setups

Compatibility

Designed for blind hole threading in alloyed and unalloyed steel. Material application is specified as alloyed and unalloyed steel. Coolant-through is not supported on this tap.

Installation Notes

This tap is installed and operated by a machinist or toolroom technician using a tapping head, CNC rigid tap cycle, or manual tap wrench. Ensure the workpiece is securely fixtured and the spindle or tapping attachment is properly aligned to the hole axis before engagement. Use a suitable cutting fluid or tapping compound rated for steel to protect both the tap and the workpiece finish. Follow OSHA and shop-floor machine guarding requirements when operating milling or drilling equipment.