Balax 13712-91L Thread Forming Tap 3/8-24 Unf 2B Hss

Product Description

The BALAX 13712-91L is a thread forming tap designed for blind hole threading in die cast aluminum. Unlike cutting taps, thread forming taps cold-form the thread profile without producing chips, making them well suited for gummy, ductile materials like aluminum alloys. This tap is manufactured from powdered metal high-speed steel (PM-HSS) for improved wear resistance and toughness over conventional HSS. It carries a Bal-Plus coating to reduce friction and extend tool life. The modified bottoming chamfer - 2.5 chamfered threads - allows threading close to the bottom of a blind hole. Overall length is 2.9375 inches with a thread length of 0.95 inches and a tapping depth of 1.25 inches.

This tap is intended for production and maintenance applications in die cast aluminum components, designated by the BXDIECAST series. Typical use cases include threading blind holes in aluminum housings, brackets, and enclosures where chip-free forming is preferred. The 3/8-24 UNF thread profile and 2B class of fit make it appropriate for standard unified fine thread fastener applications requiring a free-running fit. Right-hand thread direction is standard. The H8 thread limit accommodates the material springback inherent in aluminum forming operations.

Key Features

• Thread forming (chipless) design eliminates chip clearance concerns in blind holes
• Powdered metal high-speed steel construction for superior wear resistance versus conventional HSS
• Bal-Plus coating reduces friction and extends tool life in aluminum applications
• Modified bottoming chamfer (2.5P) allows threading close to hole bottom
• H8 thread limit accounts for aluminum springback during forming
• Single oil groove aids lubricant distribution during tapping

Compatibility

Designed for blind hole thread forming in die cast aluminum. Specified for the BALAX BXDIECAST series. Not intended for cast iron, hardened steels, or other brittle materials that do not deform plastically.

Installation Notes

Thread forming taps require a specifically sized forming tap drill - do not use standard cut tap drill sizes, as the tap drill diameter directly controls thread engagement percentage. Apply a suitable tapping fluid or cutting oil rated for aluminum before and during the tapping operation. Use a calibrated torque-controlled tapping attachment or CNC rigid tapping cycle to avoid overload on the tap shank. Ensure the workpiece is securely fixtured and that the tap is properly aligned to the hole axis before engagement.