Balax 12644-010 Thread Forming Tap 1/4-20 Unc Bottoming Hss

Product Description

The BALAX 12644-010 is a thread forming tap designed for blind hole threading in 1/4-20 UNC applications. Unlike cutting taps, thread forming taps cold-form the thread profile without producing chips, making them well suited for ductile metals where clean, strong threads are required. This tap is built from high-speed steel with a bright uncoated finish and features a bottoming chamfer with 2.5 chamfered threads, allowing it to form threads close to the bottom of a blind hole. The H4 thread limit and 3B class of fit ensure dimensional accuracy for standard fastener engagement. It is installed by machinists, maintenance technicians, and tool and die professionals.

This tap is used in production and maintenance machining environments where blind hole threading of 1/4-20 UNC fastener holes is required. The bottoming chamfer makes it appropriate for applications where thread depth must extend as close to the hole bottom as possible. The BXB series designation identifies it as a standard thread forming tap in the BALAX lineup. It is appropriate for use in ferrous and non-ferrous ductile materials in both shop and field settings.

Key Features

• Thread forming design eliminates chips, reducing the risk of chip packing in blind holes
• Bottoming chamfer with 2.5 chamfered threads for maximum thread depth in blind holes
• High-speed steel construction for durability in general-purpose tapping applications
• H4 thread limit with 3B class of fit for standard fastener compatibility
• Right-hand thread direction, single oil groove for lubrication
• Overall length of 2.5 inches with a tapping depth of 1 inch

Compatibility

Designed for blind hole threading in 1/4-20 UNC applications requiring a 3B class of fit and H4 thread limit in ductile materials.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which is larger than a standard cut tap drill size - consult a thread forming tap drill chart before use. Apply cutting or tapping fluid rated for the workpiece material to ensure proper lubrication through the single oil groove. Use a calibrated torque handle or tapping attachment to avoid overloading the tap in hard or thin-walled materials. Never reverse a thread forming tap aggressively, as the formed threads can gall if the tap is backed out without adequate lubrication.