Cleveland C58515 Spiral Flute Tap 4-40 Unc 2 Flute Hss

Product Description

The CLEVELAND C58515 is a spiral flute plug tap designed for blind hole threading in metalworking applications. Built from high speed steel with a bright, uncoated finish, it cuts a 4-40 UNC right-hand thread at 40 threads per inch. The two-flute spiral design at a 52-degree helix angle evacuates chips upward out of the hole, making it well suited for through-feed and blind hole work where chip packing is a concern. With an overall length of 1.875 inches and a thread length of 0.31 inches, this tap fits standard tapping chucks and holders sized for small-diameter thread work. Thread limit is H2, targeting a 2B and 3B class of fit.

This tap is intended for threading blind holes in alloy tool steel, carbon steel, and stainless steel. The plug chamfer provides a balance between the gradual lead of a taper tap and the bottom-cutting ability of a bottoming tap, making it the standard choice for general-purpose blind hole production. It is used in machine shops, maintenance facilities, and field repair settings wherever 4-40 UNC fastener threads are required. Belongs to Cleveland Series 1093 and 1094.

Key Features

• Spiral flute design at 52-degree helix angle for upward chip evacuation in blind holes
• High speed steel construction for durability across carbon steel, alloy tool steel, and stainless steel
• Plug chamfer for general-purpose blind and through-hole threading
• H2 thread limit producing a 2B and 3B class of fit
• Right-hand flute and right-hand thread configuration
• Bright, uncoated finish — compatible with standard cutting fluids

Compatibility

Designed for use in alloy tool steel, carbon steel, and stainless steel workpieces requiring 4-40 UNC blind hole threads. Belongs to Cleveland Series 1093 and 1094.

Installation Notes

This tap is installed by a machinist or tool and die technician using a tapping chuck, CNC machine, or tapping arm with appropriate cutting fluid for the workpiece material. Ensure the spindle speed and feed rate are appropriate for the material and tap diameter before starting. Secure the workpiece fully before tapping to prevent movement that could break the tap. Never reverse a spiral flute tap without confirming the machine is programmed for rigid tapping to avoid thread damage or tool breakage.