Cleveland C54321 Hand Tap 10-24 Unc Taper 4-flute Hss

Product Description

The CLEVELAND C54321 is a 10-24 UNC straight-flute hand tap designed for cutting internal threads in both blind holes and through holes. Built from high speed steel (HSS) with a bright, uncoated finish, it features a taper chamfer that eases thread entry and distributes cutting forces across the lead threads. The tap has four flutes, a thread limit of H2, and a class of fit rating of 2B, making it suitable for standard-tolerance threaded fastener applications. Overall length is 2.375 inches with a thread length of 0.5 inches. Machinists and maintenance technicians use this tap with a tap wrench or tapping head in manual or low-speed machine setups.

This tap is rated for use in alloy steel, aluminum, carbon steel, and free-machining stainless steel. The taper chamfer style — typically 8 to 10 threads of lead — makes it well suited for starting threads cleanly in open setups or when threading from scratch rather than chasing existing threads. It is commonly used in general metalworking shops, MRO facilities, and field maintenance applications where standard 10-24 UNC threaded holes are required. Right-hand thread direction aligns with standard right-hand fasteners throughout the UNC thread system.

Key Features

• 10-24 UNC right-hand thread, H2 thread limit, 2B class of fit for standard-tolerance applications
• Taper chamfer provides gradual thread engagement, ideal for starting new holes
• Four straight flutes in bright HSS for general-purpose cutting across a range of metals
• Compatible with both blind hole and through-hole threading operations
• Shank diameter of 0.194 inches and 0.25-inch square drive for standard tap wrenches and holders
• No coolant-through requirement — suitable for hand tapping and bench work

Compatibility

Designed for use in alloy steel, aluminum, carbon steel, and free-machining stainless steel workpieces requiring 10-24 UNC internal threads. Fits standard tap wrenches and holders that accept a 0.194-inch round shank with a 0.152-inch square drive end.

Installation Notes

Secure the workpiece and ensure the tap hole is drilled to the correct 10-24 UNC tap drill diameter before beginning. Apply cutting fluid appropriate to the workpiece material to reduce friction and extend tap life. Use a tap wrench with steady, aligned pressure — back off a quarter turn periodically to break chips, especially in blind holes. Never force a tap against resistance; a jammed tap in a blind hole is difficult to remove without damaging the part.