Balax 13172-91U Thread Forming Tap 5/16-18 Unc Bottoming

Product Description

The BALAX 13172-91U is a thread forming tap designed for blind hole threading in stainless steel applications. Built from powdered metal high-speed steel (PM-HSS) with a Super Titanium Nitride (TiN) coating, this tap cold-forms internal threads without cutting, eliminating chips in critical blind hole work. It carries a 5/16-18 UNC thread profile with a 2B class of fit and H9 thread limit. The bottoming chamfer with 2.5 thread leads allows threading close to the bottom of a blind hole. Overall length is 2.7188 inches with a thread length of 0.88 inches and a tapping depth of 1.125 inches. Machinists, tool-and-die makers, and maintenance technicians working with stainless steel components are the primary installers.

This tap is suited for blind hole threading in stainless steel, where chip evacuation is a concern and form tapping is preferred over cut tapping. The BXSTAINLESS series geometry is optimized for the work-hardening characteristics of stainless steel alloys. Typical applications include threading bosses, brackets, and structural components in manufacturing, maintenance, and repair environments where a clean, strong thread form in stainless is required. The right-hand thread direction is standard for conventional machine tapping operations.

Key Features

• Thread forming (chipless) design eliminates chip buildup in blind holes
• Powdered metal high-speed steel construction for improved wear resistance in tough materials
• Super Titanium Nitride coating reduces friction and extends tool life in stainless steel
• Bottoming chamfer with 2.5P lead allows threading to near-bottom of blind holes
• H9 thread limit for 2B class of fit on 5/16-18 UNC threads
• Single oil groove supports lubrication delivery during the forming operation

Compatibility

Designed for blind hole thread forming in stainless steel. Part of the BALAX BXSTAINLESS series, engineered specifically for stainless steel material applications.

Installation Notes

Thread forming taps require a proper forming tap drill size, which differs from standard cut tap drill charts - consult BALAX forming tap drill size recommendations before drilling. Adequate lubrication or tapping fluid formulated for stainless steel is essential to prevent galling and tool damage. Ensure the workpiece is securely fixtured and the tap is held in a rigid tapping chuck or CNC rigid tapping holder to maintain alignment. Never use this tap dry in stainless steel.