Hertel K011077AS Straight Flute Tap 5/16-18 Unc Hss

Product Description

The HERTEL K011077AS is a straight flute tap designed to cut internal 5/16-18 UNC threads in a wide range of workpiece materials. Built from high-speed steel with a bright, uncoated finish, this tap delivers consistent thread geometry in standard machine shop and maintenance environments. The plug chamfer — typically 3 to 5 threads of taper — makes it suitable for through-hole tapping applications where the tap can advance fully through the workpiece. With an overall length of 2-23/32 inches and three straight flutes, it is sized for use in manual tap handles as well as machine tapping setups. Machinists, tool-and-die makers, and MRO maintenance technicians are the primary users of this tool.

This tap is suited for production and repair threading operations where a 5/16-18 UNC Class 2B fit is required. The H5 thread limit designation indicates the tap is ground to produce threads at the upper tolerance range of the 2B class, accommodating typical plating allowances or close-fit fastener applications. It is commonly used in light fabrication, equipment repair, and manufacturing environments working with steel, aluminum, brass, and similar machinable materials. The right-hand thread direction matches the standard fastener orientation used in the vast majority of mechanical assemblies.

Key Features

• 5/16-18 UNC thread form, Class 2B fit — standard fastener thread for general mechanical assemblies
• H5 thread limit for close-tolerance threading with typical plating allowance
• Plug chamfer (3 to 5 threads) suited for through-hole tapping operations
• High-speed steel construction provides good wear resistance across common machinable metals
• Bright, uncoated finish — no coating buildup to affect thread tolerance
• Three straight flutes for chip clearance in standard tapping applications
• Right-hand thread direction matches standard UNC fastener orientation

Compatibility

Designed as a standard replacement or production tap for any application requiring 5/16-18 UNC internal threads with a Class 2B fit. Compatible with manual tap wrenches and machine tapping holders sized for the 5/16-18 shank geometry.

Installation Notes

Always secure the workpiece before tapping and use a proper cutting fluid matched to the workpiece material to extend tap life and improve thread finish. Ensure the tap is started square to the hole to prevent thread runout or tap breakage. For machine tapping, set spindle speed and feed rate appropriate to the material and tap diameter. Inspect the tap regularly for chipping or wear and replace before thread quality degrades.