Balax 12772-91U Thread Forming Tap 1/4-20 Unc Bottoming Tin

Product Description

The BALAX 12772-91U is a bottoming-style thread forming tap designed for cutting 1/4-20 UNC internal threads to a 2B class of fit. Built from powdered metal high-speed steel and coated with Super Titanium Nitride (TiN), this tap is engineered specifically for blind hole threading in stainless steel applications. Thread forming taps displace material rather than cut chips, producing stronger threads with no swarf to clear from the hole. At 2.5 inches overall length with a 0.79-inch thread length and a 1.0-inch tapping depth, this tap suits tight-tolerance work where a bottoming chamfer is required to thread as close to the bottom of the hole as possible.

This tap is intended for use in stainless steel materials, where work hardening and tool wear are primary concerns. The BXSTAINLESS series designation indicates it is optimized for the demands of stainless alloys. It is suited to production and maintenance machining environments where blind holes require maximum thread depth. The bottoming chamfer - 2.5 thread lead-in - allows the tap to form threads within a few pitches of the hole bottom, making it appropriate for applications with minimal clearance below the thread.

Key Features

• Thread forming (chipless) design produces stronger threads and eliminates chip evacuation concerns in blind holes
• Powdered metal high-speed steel construction offers improved toughness and wear resistance over conventional HSS
• Super Titanium Nitride coating extends tool life and reduces friction when tapping stainless steel
• Bottoming chamfer (2.5P) threads close to the bottom of blind holes
• H8 thread limit provides consistent fit for 2B class applications
• Single oil groove aids lubrication during the forming process

Compatibility

Designed for blind hole thread forming in stainless steel workpieces requiring 1/4-20 UNC threads at a 2B class of fit. Part of the BALAX BXSTAINLESS series.

Installation Notes

Thread forming taps require a properly sized forming tap drill - not a standard tap drill - to achieve the correct minor diameter before tapping. Use a quality cutting oil or tapping fluid rated for stainless steel to prevent galling and extend tap life. Secure the workpiece firmly and ensure the tap is driven straight and square to the hole. Do not back the tap out under power without confirming the machine setup supports reversing torque.