Hertel K008320AS Straight Flute Tap 1/4-20 Unc Hss

Product Description

The HERTEL K008320AS is a straight flute plug tap designed for cutting internal threads in through-holes and shallow blind holes. Built from high-speed steel with a bright/uncoated finish, this tap cuts 1/4-20 UNC right-hand threads to a 3B class of fit with an H3 thread limit. Four straight flutes provide chip clearance and support accurate thread formation in a range of ferrous and non-ferrous materials. Overall length is 2.5 inches, and the plug chamfer — typically 3 to 5 threads — allows easy thread lead-in. Machinists, maintenance technicians, and toolroom professionals install this tap by hand or machine in standard tapping operations.

This tap is suited for general-purpose tapping in production and maintenance environments where 1/4-20 UNC threads are required. Straight flute geometry makes it appropriate for use in softer materials and short-chipping metals. The 3B class of fit meets standard tolerances for most fastener and mechanical assembly applications requiring a free-running thread fit. It is sold individually and is a direct bench-stock replacement for worn or broken taps of the same specification.

Key Features

• 1/4-20 UNC thread form, right-hand cut
• 4 straight flutes for chip relief in short-chipping materials
• Plug chamfer for guided thread lead-in in through-holes and shallow blind holes
• H3 thread limit for consistent 3B class of fit tolerance
• High-speed steel construction for durability in general tapping applications
• Bright/uncoated finish — no coating buildup to affect thread tolerance

Compatibility

Designed as an OEM-style replacement straight flute tap for any application requiring a 1/4-20 UNC, 4-flute, plug chamfer, H3 limit, 3B class of fit tap in high-speed steel.

Installation Notes

This tap is installed by licensed machinists or qualified maintenance technicians using a standard tap wrench, tapping head, or CNC tapping cycle. Power down or disable any machine spindle before inserting or removing the tap from the holder. Apply appropriate cutting fluid for the workpiece material to extend tool life and protect thread quality. Do not force a tap that binds — back off to clear chips before continuing.