Import BDNA-20738 Straight Flute Tap 5/16-18 Unc Hss

Product Description

The IMPORT BDNA-20738 is a straight flute bottoming tap designed for cutting internal threads in through-holes and blind holes where full thread depth close to the bottom is required. Built from high-speed steel (HSS) with a gold oxide coating, this tap offers improved wear resistance and reduced friction during the cutting process. The 5/16-18 UNC thread specification and H3 thread limit ensure accurate, consistent thread form for standard unified coarse-pitch applications. With 4 straight flutes and a right-hand thread direction, it is suited for use in conventional manual or machine tapping operations on ferrous and non-ferrous materials.

This tap is intended for general metalworking and maintenance applications where a 5/16-18 UNC bottoming tap is required. The bottoming chamfer — typically 1 to 2 thread leads — allows threading to within a few threads of the bottom of a blind hole, making it a common choice for repair work, fabrication shops, and production tapping where full thread engagement depth is critical. It is appropriate for use in drill presses, tapping machines, or by hand with a tap wrench. The H3 thread limit suits a range of standard nut and fastener fits.

Key Features

• 5/16-18 UNC thread size with right-hand thread direction
• Bottoming chamfer for threading close to the bottom of blind holes
• 4 straight flutes for chip control in a variety of materials
• High-speed steel construction for durability in manual and machine tapping
• Gold oxide coating reduces friction and improves tool life
• H3 thread limit for standard unified coarse-pitch fastener fits

Compatibility

Designed as a standard 5/16-18 UNC bottoming tap suitable for use with compatible tap wrenches, T-handle wrenches, and tapping heads that accept straight-shank taps of this size.

Installation Notes

Tapping operations should be performed by a qualified machinist or maintenance technician familiar with thread cutting procedures. Always secure the workpiece and use the appropriate cutting fluid for the material being tapped to extend tool life and ensure clean thread form. Back the tap out periodically to clear chips, especially in blind holes. Inspect the tap for wear or damage before each use and do not apply excessive torque, which can cause tap breakage.