Greenfield Threading Spiral Point Tap Plug 282256 3 Flutes #10-32 UNF HSS

Spiral Point Tap #10-32 UNF

This spiral point tap cuts #10-32 UNF threads in through-holes and deep blind holes. Its three-flute high-speed steel design pushes chips forward, reducing clogging and torque. The H3 thread limit produces a 2B class of fit for general-purpose fastening. Right-hand cutting suits standard thread direction.

Practical limits of UNF fine threads

The UNF fine pitch requires a #21 drill at 75 percent thread depth for proper engagement. Spiral point geometry works best in through-holes or blind holes with enough clearance for chips to exit ahead of the tap. High-speed steel bright finish performs well in mild steel and aluminium but wears faster in hardened alloys. Lubrication is essential to maintain thread quality and tool life.

Replaces worn or undersized taps

This tap replaces dull, chipped or incorrect-limit taps that produce loose or oversized threads. The jump is worth it when existing tools no longer hold the 2B tolerance or when chip evacuation becomes a bottleneck. Builders needing coarse-thread UNC or metric sizes must select a different tap. Left-hand thread applications also require a separate tool.