Cleveland C55319 Spiral Point Tap 5/16-18 Unc Tin Hss

Product Description

The CLEVELAND C55319 is a spiral point tap designed for through-hole threading in ferrous materials. Built from high speed steel with a titanium nitride (TiN) coating, it provides extended tool life and reduced friction during cutting. The plug chamfer style makes it well suited for starting threads in through holes where the tap can advance freely. With 2 flutes and a right-hand thread direction, it cuts 5/16-18 UNC threads to a Class 2B fit and H2 thread limit. This tap is used by machinists, maintenance technicians, and fabricators working in production or job-shop environments.

This tap is intended for through-hole threading operations in cast iron and steel workpieces. The spiral point geometry pushes chips forward ahead of the tap rather than packing them into the flutes, making it effective in continuous through-hole applications. At 2.72 inches overall length with an 11/16-inch thread length, it fits standard tap holders and CNC tapping heads. It is not designed for blind-hole applications where chip evacuation forward is not possible.

Key Features

• 5/16-18 UNC thread form, Class 2B fit, H2 thread limit for standard tolerance threading
• High speed steel construction for durability in steel and cast iron
• TiN coating reduces friction and extends cutting life compared to uncoated HSS
• Spiral point (gun tap) geometry pushes chips forward, ideal for through-hole applications
• Plug chamfer for easy thread starting in through holes
• Right-hand cut, no coolant-through requirement

Compatibility

Designed for through-hole threading in cast iron and steel. Compatible with standard tap holders, floating tap holders, and CNC rigid tapping setups accepting the 0.318-inch shank diameter of the CLEVELAND 1011TN series.

Installation Notes

This tap should be installed by a machinist or maintenance technician using a properly sized tap holder or tapping head. Secure the workpiece before operation and ensure the spindle is aligned axially with the hole to prevent tap breakage. Use a cutting fluid or tapping compound appropriate for the workpiece material. Inspect the tap for wear or chipping before each use and replace if cutting edges show damage.