Industrial B1398P GTD 1 1 4-12 Plug Hand Tap NF G H4 is a plug-type hand tapping tool designed to cut internal threads in metal by hand. It uses National Fine (NF) threading with a 1 1 4-12 size designation, and its GTD/B1398P/H4 markings identify its specific configuration within the GTD family. The tool is intended for manual tapping applications where precise internal threads are required.
