Glow Plug Thread "Cleaner"
High quality hardened steel chaser die, "cleans" (removes imperfections and burrs) from 1/4-32 in. glow and spark plug threads.
Use on new glow plugs to optimize the thread and help prevent damage to the relatively soft cylinder head.
Very useful hand-tool for every field box.

For more information and option to buy link to:
www.sigmfg.com