Balax 13508-010 Extension Thread Forming Tap 3/8-16 H8

Product Description

The BALAX 13508-010 is a thread forming extension tap designed for cutting 3/8-16 UNC internal threads in applications where standard-length taps cannot reach. Built from high-speed steel with a bright, uncoated finish, this tap uses a bottoming chamfer to form threads close to the bottom of blind holes. The H8 thread limit ensures consistent Class 2B fit tolerances for reliable thread engagement. At 4 inches overall length with a 1-1/4 inch thread length, it provides the reach needed for deep or recessed tapping operations in metal fabrication and machining work.

This extension tap is suited for production and job-shop environments where standard reach is insufficient due to part geometry, fixturing, or deep-cavity access requirements. Thread forming construction displaces material rather than cutting chips, which reduces tap breakage risk and produces stronger threads in ductile materials such as aluminum, mild steel, and brass. It is used by machinists, tool-and-die makers, and maintenance technicians working with UNC threaded assemblies.

Key Features

• Thread forming bottoming chamfer for threading close to the base of blind holes
• H8 thread limit for Class 2B fit tolerance compliance
• High-speed steel construction provides wear resistance in general-purpose machining
• 4 inch overall length extends reach into deep or recessed features
• Right-hand flute direction for standard clockwise tapping operations
• Bright uncoated finish suitable for use with cutting fluids and tapping compounds

Compatibility

Designed as an OEM-style replacement or production tap for 3/8-16 UNC thread forming applications requiring extended reach and a bottoming chamfer in compatible tapping equipment.

Installation Notes

Thread forming taps require adequate lubrication with an appropriate tapping fluid for the workpiece material. Ensure the tap driver or tapping head is properly aligned to the pilot hole to avoid tap breakage. Always verify that the pilot hole diameter is correct for thread forming operations, as it differs from cut-tap pilot hole requirements. Power down and secure the workpiece before changing or setting taps in machine tooling.