Dear Welder Series…
I tried to attach these to the review but it wouldn’t let me. I found that if I used a step drill and drilled the finish dia of the plug (5/8″) 1/2 way thru it left enough shelf to support the plug and was tight enough to fuse with the TIG.
I hope this helps,
Jim

Dear Jim…
Great idea! I hope someone else sees this and is able to make use of it. I always find it a bit of a hitch in my step when the next size on the step drill isn’t quite far enough away to go through the whole thickness of the material, and it leaves a lip that needs to be removed… this idea almost redeems that :).