Hertel K008387AS Straight Flute Tap 5/16-18 Unc Bottoming

Product Description

The HERTEL K008387AS is a straight flute bottoming tap designed for cutting right-hand internal threads in a wide range of materials. Built from high-speed steel with a bright, uncoated finish, it produces 5/16-18 UNC threads to a 2B class of fit and H5 thread limit. The four-flute, straight-flute geometry suits through-holes and shallow blind holes where chip clearance requirements are moderate. Overall length is 2-23/32 inches. The bottoming chamfer allows threading close to the bottom of a blind hole, making this tap a common final-pass tool in a tap set sequence. Machinists and maintenance technicians use it in job shops, toolrooms, and field repair applications.

This tap is suited for threading operations in ferrous and non-ferrous materials where a standard 5/16-18 UNC bottoming thread is required. Typical applications include repair threading of stripped fastener holes, production tapping in light manufacturing, and maintenance work on mechanical assemblies. The bright, uncoated finish makes it appropriate for use with cutting oils and standard tapping fluids in moderate-duty applications. It is sold individually and well-suited for low-volume work or single-job replacement needs.

Key Features

• Bottoming chamfer for threading to the bottom of blind holes
• 4 straight flutes for chip clearance in through and shallow blind-hole applications
• High-speed steel construction for durability across a range of workpiece materials
• 5/16-18 UNC thread form to 2B class of fit and H5 thread limit for dimensional accuracy
• Right-hand thread direction, the standard for most fastener applications
• Bright, uncoated finish compatible with standard cutting oils and tapping fluids

Compatibility

Designed for cutting standard 5/16-18 UNC internal threads; compatible with standard tap holders, T-handle wrenches, and tapping heads sized for the 5/16-18 shank geometry.

Installation Notes

Threading operations should be performed by a qualified machinist or maintenance technician familiar with proper tapping technique. Always secure the workpiece before tapping and apply appropriate cutting oil to reduce heat and extend tool life. Use a correctly sized tap wrench or machine holder to keep the tap aligned perpendicular to the work surface and avoid tap breakage. Back the tap out periodically to break and clear chips, especially when working in deeper or blind holes.