Hertel K010377AS Thread Forming Tap 5/16-18 Unc Plug Hss

Product Description

The HERTEL K010377AS is a thread forming tap designed for creating internal 5/16-18 UNC threads in through-hole applications. Unlike cutting taps, thread forming taps displace material rather than cut it, producing stronger threads with no chips to clear. This tap is manufactured from high-speed steel with a bright uncoated finish and carries an H5 thread limit for consistent dimensional control. It features a plug chamfer with 3 to 5 chamfered threads for gradual thread engagement. With an overall length of 2.7188 inches and a thread length of 1.125 inches, it fits standard tap holders used in machine shop and field service environments. Licensed machinists, tool and die workers, and maintenance mechanics are the primary installers.

This tap is suited for through-hole threading operations in metalworking, maintenance repair, and manufacturing applications. The 5/16-18 UNC coarse thread form is a widely used fastener standard in structural assemblies, equipment frames, and mechanical systems. The plug chamfer makes it appropriate for both hand tapping and machine tapping where the tap can pass fully through the workpiece. It is a right-hand tap and is not designed for blind-hole applications where chip evacuation is a concern, since the forming action eliminates chips entirely, making it effective in ductile materials such as aluminum, copper, and mild steel.

Key Features

• Thread forming action displaces material instead of cutting, producing stronger threads with no chips
• 5/16-18 UNC thread form with right-hand direction and 2B class of fit
• H5 thread limit for precise dimensional consistency
• Plug chamfer with 3 to 5 chamfered threads for gradual thread engagement
• High-speed steel construction for durability in production and maintenance use
• Bright uncoated finish suitable for use with standard tapping fluids

Compatibility

Designed for through-hole thread forming in workpieces requiring 5/16-18 UNC internal threads. Compatible with standard tap holders and machine spindles accepting a 0.318-inch shank diameter with a 0.238-inch square drive.

Installation Notes

Thread forming taps require a properly sized forming tap drill hole, which is larger than the drill size used for a cutting tap of the same thread specification - consult a thread forming tap drill chart before drilling. Secure the workpiece fully before tapping and apply an appropriate tapping fluid for the workpiece material. For machine tapping, verify spindle speed and feed rate are matched to the material and tap size. Inspect the tap for wear or deformation before each use and replace if the shank or thread form shows damage.