Import BDNA-20740 Straight Flute Tap 7/16-14 Unc Bottoming Hss

Product Description

The IMPORT BDNA-20740 is a straight flute bottoming tap designed to cut internal threads in pre-drilled holes where full thread depth is required close to the bottom of a blind hole. Built from high-speed steel (HSS) with a gold oxide coating, this tap offers improved lubricity and corrosion resistance during threading operations. It cuts a 7/16-14 UNC right-hand thread with 4 flutes and carries an H3 thread limit, suitable for achieving consistent tolerance fits in standard ferrous and non-ferrous materials. Machinists and maintenance technicians use this tap for production and repair threading work.

This tap is suited for threading operations in machine shops, maintenance facilities, and fabrication environments. The bottoming chamfer allows threads to be cut as close to the bottom of a blind hole as possible, making it the correct choice when a plug or taper tap cannot produce sufficient thread engagement at depth. It is compatible with standard tap handles, T-handle wrenches, and machine tapping setups running at appropriate speeds for HSS tooling.

Key Features

• 7/16-14 UNC thread form for standard unified coarse thread applications
• Bottoming chamfer (1-2 thread lead) allows threading to near full depth in blind holes
• High-speed steel construction provides durability across a range of workpiece materials
• Gold oxide coating improves lubricity and reduces friction during the cutting process
• H3 thread limit ensures consistent tolerance for standard fit classes
• 4-flute design provides good chip distribution and thread finish in through and blind hole applications

Compatibility

Designed as a standard bottoming tap for use in 7/16-14 UNC threaded hole applications across general machining, maintenance, and repair operations.

Installation Notes

This tap should be installed and used by qualified machinists or maintenance technicians familiar with threading operations. Always ensure the workpiece is securely clamped before tapping. Use an appropriate cutting fluid to extend tool life and improve thread quality. When tapping blind holes, use a plug tap first to establish the thread, then follow with this bottoming tap to complete threading to depth.