Balax 12312-91L Thread Forming Tap 10-32 Unf Bottoming

Product Description

The BALAX 12312-91L is a thread forming tap designed for blind hole threading in die cast aluminum. It cuts no chips - instead, it cold-forms the thread profile by displacing material, which produces stronger threads and eliminates chip-clearing concerns in tight cavities. Built from powdered metal high-speed steel (PM-HSS), the tap delivers consistent hardness and wear resistance across the cutting profile. The Bal-Plus coating reduces friction and extends tool life in high-cycle production environments. This tap carries a 10-32 UNF thread specification with a 2B class of fit and an H5 thread limit, making it suitable for close-tolerance fastener assemblies where dimensional consistency is critical.

This tap is intended for use in die cast aluminum applications, specifically blind hole threading where chip evacuation is a concern and thread strength is a priority. The bottoming chamfer - with 2.5 chamfered threads - allows threading close to the bottom of a blind hole, maximizing usable thread engagement in shallow bosses. It is well suited for production machining, fixture fabrication, and repair work on aluminum die cast housings and components. Machinists and tool and die technicians are the primary users in CNC, manual mill, and tapping machine setups.

Key Features

• Thread forming design produces no chips - eliminates chip packing in blind holes
• Powdered metal high-speed steel construction for uniform hardness and extended tool life
• Bal-Plus coating reduces friction and improves performance in aluminum die cast material
• Bottoming chamfer with 2.5 chamfered threads for maximum thread depth in shallow blind holes
• H5 thread limit for close-tolerance 2B class of fit on 10-32 UNF threads
• Single oil groove supports lubrication flow during the forming process

Compatibility

Designed for blind hole thread forming in die cast aluminum workpieces. Suited for 10-32 UNF tapped holes requiring a 2B class of fit with an H5 thread limit. Series designation is BXDIECAST, indicating optimization for die cast aluminum material applications.

Installation Notes

Thread forming taps require the correct tap drill size for the material and thread form - use the recommended forming tap drill diameter for 10-32 UNF in aluminum before tapping. Apply a suitable tapping fluid or cutting oil rated for aluminum to reduce heat and improve surface finish in the formed thread. Secure the workpiece fully before tapping, whether using a CNC machine, tapping arm, or manual drill press, to maintain perpendicularity and avoid tap breakage. Never attempt to reverse a thread forming tap at speed without confirming the machine is set for proper reversal to prevent galling the formed thread.