Cleveland C57644 Spiral Point Tap 3/4-10 Unc Hss

Product Description

The CLEVELAND C57644 is a 3/4-10 UNC spiral point plug tap designed for through-hole threading operations in ferrous materials. Built from high speed steel (HSS) with an oxide finish, it delivers the wear resistance and heat tolerance required for production-volume tapping in cast iron and steel. The plug chamfer geometry provides a gradual thread lead-in, reducing torque requirements on entry. With 3 flutes and a spiral point design, chips are pushed forward ahead of the tap during cutting, keeping flute channels clear and reducing the risk of chip packing in through-hole applications.

This tap is suited for through-hole threading in a machine-shop or field fabrication context where 3/4-10 UNC threads are required. It carries a class 2B thread fit, which is the standard tolerance for most general-purpose UNC fastener applications. The H3 thread limit provides a slightly oversized thread form to account for material springback, particularly relevant when tapping steel and cast iron. It is installed using a tap holder or rigid tapping chuck in a drill press, mill, or tapping machine, and is appropriate for both manual machine operation and CNC tapping cycles.

Key Features

• Spiral point design pushes chips forward, optimized for through-hole threading
• 3/4-10 UNC thread form with H3 thread limit for general-purpose class 2B fit
• High speed steel construction provides heat and wear resistance in steel and cast iron
• Plug chamfer for standard lead-in in production and maintenance tapping
• Oxide finish improves lubrication retention and reduces galling
• Right-hand thread direction, compatible with standard tapping setups

Compatibility

Designed for through-hole threading in cast iron and steel workpieces requiring 3/4-10 UNC class 2B threads. Suitable for use with standard tap holders and rigid tapping chucks in drill press, milling machine, and CNC tapping applications.

Installation Notes

Tapping should be performed by a machinist or qualified tradesperson using appropriate tapping fluid or cutting oil for the workpiece material. Ensure the workpiece is securely fixtured and the tap is properly aligned to the drilled hole before engagement. Use a correctly sized tap drill to achieve the specified thread depth and fit class. Do not force or reverse a tap that has seized, as this may cause breakage and workpiece damage.