These tophat-shaped, blind threaded steel bungs are perfect for making gas tank and oil tank mounts, or for any other fluid filled vessel. Mild steel for easy weldability. 3/4" OD with a 1" OD flange that is 1/8" thick. The overall length is 1". Featuring a 5/16"-18 thread. These blind threaded bungs are a perfect match for our rubber mount finger or triangular tabs to get your oil tank or gas tank mounted in no time at all. Sold in 4 packs. Made in Ohio, USA.