Cleveland C59318 Thread Forming Tap 3/8"-16 UNC Bottoming HSS Bright H7 2.94in

Cleveland C59318 Thread Forming Tap

This Cleveland C59318 thread forming tap creates internal threads in ductile materials by displacing metal rather than cutting it. It is designed for machinists and maintenance technicians who need strong, chipless threads in a single pass. The high speed steel construction provides the hardness required for forming threads in materials such as aluminium, brass and mild steel. Its bright, uncoated finish suits general-purpose workshop use.

Replaces Cutting Taps In Formable Materials

Switching from a conventional cutting tap to this forming tap is worthwhile when the workpiece material is ductile enough to flow without tearing. The forming action eliminates chips, which removes the risk of chip packing in blind holes and reduces tap breakage. Threads produced by forming have a smoother surface and higher tensile strength because the grain structure of the metal is compressed rather than severed. The jump is not worth it for brittle materials such as cast iron or hardened alloys where cutting remains the only reliable method.

Handles 3/8"-16 UNC Threads With H7 Limits

This tap produces a 3/8"-16 UNC thread to a class of fit of 2B-3B with an H7 thread limit. The overall length is 2.94 inches and the thread length is 0.75 inches, giving sufficient reach for typical through and blind holes. A 75 percent thread drill size of 11/32 inch is specified to prepare the correct hole diameter for forming. The tool runs out of effective range when the material hardness exceeds the forming capability of high speed steel or when the hole depth requires a longer shank than the 2.94 inch overall length provides.