Hertel K008388AS Straight Flute Tap 5/16-18 Unc Hss

Product Description

The HERTEL K008388AS is a straight flute plug tap designed for cutting 5/16-18 UNC right-hand internal threads in a wide range of workpiece materials. Built from high-speed steel with a bright, uncoated finish, this 4-flute tap delivers consistent thread quality in through-hole and shallow blind-hole applications. It carries an H11 thread limit, indicating a slightly oversize ground thread for use in applications requiring a tighter tolerance fit. Overall length is 2-23/32 inches, and the oversize amount is 0.0050 decimal inch. Machinists, tool-and-die technicians, and maintenance mechanics rely on this style of tap for production and repair threading operations.

This tap is suited for use in conventional drill press, CNC tapping, and hand-tapping setups where straight flute geometry is appropriate. The plug chamfer - typically 3 to 5 threads - makes it a general-purpose choice for starting threads in through holes or for following a taper tap in blind holes. It is well-suited for threading steel, aluminum, and other machinable metals where coolant-through capability is not required. The bright finish reduces cost while maintaining acceptable performance in lower-speed or intermittent-duty tapping cycles.

Key Features

• 5/16-18 UNC thread form for standard fractional inch fastener applications
• 4-flute straight flute design provides rigidity and chip control in through-hole tapping
• Plug chamfer for general-purpose thread starting without a separate taper tap
• High-speed steel construction handles a broad range of machinable workpiece materials
• H11 thread limit with 0.0050-inch oversize for controlled thread tolerance
• Bright/uncoated finish - no coolant-through requirement simplifies setup

Compatibility

Designed as a standard replacement or production tap for any setup requiring a 5/16-18 UNC straight flute plug tap with an H11 thread limit in high-speed steel.

Installation Notes

Installation and use of this tap should be performed by a qualified machinist or maintenance technician familiar with threading operations. Always secure the workpiece and ensure the tap is properly aligned to the drilled hole before beginning the threading cycle to prevent tap breakage. Use an appropriate tapping fluid or cutting oil for the workpiece material to extend tool life. Inspect the tap for wear or damage before each use and replace if chipping or dulling is observed.