Accupro 40125-01T Spiral Flute Tap 3/8-16 Unc Tin Coated

Product Description

The ACCUPRO 40125-01T is a spiral flute tap designed for cutting 3/8-16 UNC internal threads in through-holes and shallow blind holes. Built from powdered metal with a titanium nitride (TiN) coating, it delivers extended tool life in ferrous and non-ferrous materials compared to standard high-speed steel taps. The modified bottoming chamfer allows threading closer to the bottom of a blind hole than a plug or taper chamfer. The fast-spiral 42-degree helix angle evacuates chips up and out of the hole during the tapping cycle, reducing chip packing and tap breakage. This tap is sized at 2-15/16 inches overall length and is suitable for use in CNC machining centers, drill presses, and hand tapping applications.

This tap is used in general metalworking and production machining environments where 3/8-16 UNC threads are required. The 2B class of fit is the standard tolerance for most commercial fastener applications, making this tap appropriate for producing threads that accept standard 3/8-16 bolts and screws. The H5 thread limit designation indicates a controlled oversize suitable for TiN-coated taps, compensating for the coating layer to hold 2B tolerance. Machinists, tool and die makers, and maintenance technicians working in job shops, manufacturing facilities, and industrial maintenance settings will find this tap appropriate for both production runs and one-off repair work.

Key Features

• 42-degree right-hand spiral helix for efficient chip evacuation in blind and through-hole applications
• TiN coating increases surface hardness and reduces friction, extending tool life over uncoated taps
• Modified bottoming chamfer allows threading closer to the bottom of a blind hole
• Powdered metal substrate provides a fine-grain structure for improved edge retention
• H5 thread limit calibrated for TiN-coated taps to maintain 2B class of fit tolerance
• Right-hand thread direction, compatible with standard tapping drivers and tap handles

Compatibility

Designed as a replacement or production tap for any application requiring 3/8-16 UNC internal threads to a 2B class of fit. Fits standard 3/8-inch tap holders and tapping chucks with appropriate drive styles.

Installation Notes

Tapping should be performed by a machinist or qualified metalworking technician using the appropriate cutting fluid for the workpiece material. Ensure the tap is properly aligned with the drilled pilot hole before beginning the tapping cycle to avoid tap breakage. For machine tapping, use a tension-compression tapping chuck or rigid holder appropriate for spiral flute taps. Always de-energize and lock out any powered equipment before performing manual tapping operations in a live machine.