Cleveland C58564 Spiral Flute Tap 1/4-28 Unf Hss

Product Description

The CLEVELAND C58564 is a spiral flute plug tap designed for blind hole threading in ferrous and alloy materials. Built from high speed steel (HSS) with a bright/uncoated finish, it cuts a 1/4-28 UNF right-hand thread to a 3B class of fit. The fast-helix flute geometry at 52 degrees pulls chips up and out of the hole during tapping, which is critical in blind hole applications where chip packing causes tap breakage. Thread length is 0.63 inches over a 2.5-inch overall length. This tap is sized for use with standard tap wrenches or machine tapping heads and is installed by licensed machinists, tool and die makers, and maintenance technicians.

The C58564 is suited for blind hole threading operations in alloy steel, carbon steel, and stainless steel workpieces. The plug chamfer — typically 3 to 5 threads — provides a balance between starting ease and thread length, making it appropriate for general-purpose machine tapping and hand tapping where through-hole access is not available. It fits Series 1093 and 1094 tooling lines and is sold individually.

Key Features

• 52-degree fast helix flute design evacuates chips upward out of blind holes during cutting
• 1/4-28 UNF thread form with 3B class of fit for standard tolerance threaded assemblies
• H3 thread limit for consistent fit control in production and maintenance applications
• High speed steel construction provides durability across alloy steel, carbon steel, and stainless steel
• Plug chamfer for versatile hand or machine tapping starts
• Bright/uncoated finish — no coating buildup risk on close-tolerance threads

Compatibility

Designed for use in alloy tool steel, carbon steel, and stainless steel workpieces requiring a 1/4-28 UNF 3B class of fit blind hole thread. Compatible with Cleveland Series 1093 and 1094 tooling.

Installation Notes

Machinists and maintenance technicians should secure the workpiece and ensure the tap is properly aligned to the drilled hole before applying cutting pressure. Always use the correct tap drill size for the 1/4-28 UNF thread form and apply appropriate cutting fluid to extend tool life, particularly in stainless steel. Do not reverse the tap under power — back out manually to break and clear chips when hand tapping blind holes. Inspect the tap for wear or chipping before each use.