Hertel K008923AS Tap Set 5/16-18 Unc 4 Flute Hss

Product Description

The HERTEL K008923AS is a 3-piece tap set designed for cutting 5/16-18 UNC internal threads in metal workpieces. Built from high speed steel (HSS) with a bright finish, this set delivers consistent thread formation across a range of material hardnesses. The 4-flute geometry provides efficient chip evacuation and stable cutting action. Overall length is 2-23/32 inches, and the set covers both 2B and 3B class of fit applications, making it suitable for standard and close-tolerance threaded assemblies. Machinists, maintenance technicians, and tool-and-die professionals rely on this type of tap set for production and repair threading operations.

This tap set is suited for threading operations in light manufacturing, machine shops, and maintenance environments where 5/16-18 UNC thread profiles are required. The H3 thread limit designation makes it appropriate for plated or close-tolerance fit applications. The 3-piece set typically includes a taper, plug, and bottoming tap, allowing complete through-hole and blind-hole threading in a single kit. It is well matched to hand tapping and low-speed machine tapping setups.

Key Features

• 5/16-18 UNC thread profile for standard fractional fastener applications
• High speed steel construction for durability across a range of workpiece materials
• 4-flute design for stable cutting and effective chip removal
• H3 thread limit supports plated and close-tolerance fit requirements
• Covers 2B and 3B class of fit in a single set
• Bright finish, uncoated — suitable for use with cutting fluid

Compatibility

Designed for cutting 5/16-18 UNC internal threads; compatible with standard 5/16-18 UNC fastener assemblies requiring 2B or 3B class of fit.

Installation Notes

Tap installation should be performed by a qualified machinist or maintenance technician. Always secure the workpiece firmly and use appropriate cutting fluid to extend tool life and improve thread quality. For hand tapping, use a calibrated tap wrench and advance in reverse periodically to break chips. For machine tapping, verify spindle speed and feed rate are appropriate for the workpiece material before starting.