Balax 13146-010 Thread Forming Tap 5/16-18 Unc H6 Hss

Product Description

The BALAX 13146-010 is a thread forming extension tap in 5/16-18 UNC, designed for cold-forming internal threads without cutting flutes or producing chips. It runs in right-hand flute direction with an H6 thread limit and a bottoming chamfer, making it suited for threading blind holes to near-full depth. The overall length of 4 inches provides reach in confined or deep-access applications. Manufactured from high-speed steel with a bright uncoated finish, it fits a 3B class of fit and is part of the BXEXT series. Machinists and tool-room technicians use this tap in both CNC and manual tapping operations where chip-free thread forming is required.

This tap is intended for use in ductile and malleable materials where thread forming is preferred over thread cutting, such as aluminum, copper, and soft steels. The bottoming chamfer allows threads to be formed close to the bottom of a blind hole. The 1-1/8 inch thread length provides adequate engagement for standard fastener depths in 5/16-18 applications. The extension-length body at 4 inches OAL is useful when standard-length taps cannot reach the workpiece, including recessed bosses, deep pockets, or fixturing setups on production machines.

Key Features

• Thread forming design produces no chips, reducing the risk of chip packing in blind holes
• Bottoming chamfer allows thread forming to within one to two pitches of hole bottom
• H6 thread limit provides controlled oversize for consistent 3B class of fit
• 4-inch overall length extends reach in deep or obstructed work areas
• High-speed steel construction handles moderate production volumes and manual tapping
• Bright uncoated finish suitable for use with standard tapping fluids

Compatibility

Designed for use in 5/16-18 UNC tapped-hole applications requiring a 3B class of fit. Thread forming is compatible with ductile materials; verify material suitability before use in harder or brittle substrates.

Installation Notes

Thread forming taps require a properly sized forming hole, which is typically larger than a standard drill size for cut taps - consult the manufacturer's forming drill chart for the correct pilot hole diameter. Use a suitable tapping fluid or cutting oil for the workpiece material to reduce torque and extend tap life. Ensure the tap is properly aligned with the hole axis before engagement to prevent tap breakage or thread distortion. Secure the workpiece fully before tapping operations begin.