Cleveland C57638 Spiral Point Tap 1/2-20 Unc Hss Oxide

Product Description

The CLEVELAND C57638 is a spiral point plug tap designed for through-hole threading in metal workpieces. It cuts a 1/2-20 UNC right-hand thread and is manufactured from high speed steel with an oxide finish for lubricity and corrosion resistance. The spiral point geometry pushes chips forward ahead of the cut, keeping the flutes clear during blind or through-hole operations. With three flutes and an H3 thread limit, it holds a Class 2B fit tolerance suitable for general-purpose fastener threads. Machinists and tool-and-die tradespeople use this tap in production and maintenance applications where clean thread form and consistent sizing are required.

This tap is suited for through-hole threading in cast iron and steel workpieces. The plug chamfer style distributes cutting load across several leading threads, making it appropriate for CNC tapping centers, drill presses, and hand tapping operations where the tap can pass fully through the material. The 3-3/8 inch overall length provides adequate reach for standard workholding setups, and the 0.367 inch shank diameter fits standard tap holders and chucks.

Key Features

• Spiral point geometry pushes chips forward for efficient through-hole threading
• High speed steel construction withstands heat generated during cutting in cast iron and steel
• Oxide finish reduces friction and improves lubricant retention at the cutting edge
• H3 thread limit holds Class 2B fit tolerance for general-purpose fastener threads
• Plug chamfer distributes cutting load for smooth entry and consistent thread form
• Right-hand cut, 1/2-20 UNC thread specification for standard unified coarse applications

Compatibility

Designed for through-hole threading of cast iron and steel workpieces requiring a 1/2-20 UNC Class 2B right-hand thread.

Installation Notes

Installation of this tap should be performed by a qualified machinist familiar with proper speeds, feeds, and cutting fluid selection for the workpiece material. Always secure the workpiece firmly before tapping and use appropriate cutting fluid for cast iron or steel to extend tool life. Ensure the tap is properly aligned with the pilot hole to prevent tap breakage. For power tapping operations, verify the tapping attachment or CNC control provides adequate torque control and reversal to avoid overloading the tap.