How did they do it ?

[Robert Hayward]

I am putting new boards on an older cast iron bench. The old boards are held on with stainless steel threaded inserts and stainless steel phillips head bolts in 1/4-20 thread. Could not figure out how to remove the inserts so i split a board. There is no apparent means of inserting or removing the threaded insert. How did whoever made this bench install the inserts? The inserts are the same on each end. They could be installed either end into the wood first from what I can tell.

[Edwin Santos]

They used a bolt with two hex nuts jammed together. The method can be used for installation and removal.

Here is a link to a YouTube video that explains it visually better than I can do so here: https://www.youtube.com/watch?v=tIhEqoKE8Dc

[Terry Therneau]

You insert them with a shoulder bolt, or there is a special wrench for them that works out to the same thing. Screw the insert in, unscrew the bolt.

[Ben Ellenberger]

For something like that I would find a rod with the right thread to go in the insert. Then I would thread one nut on until it was snug to the insert (not tight!). Then tighten a second nut to the first. Lock the nuts together with a wrench on each. You drive the whole thing in using the second nut. Once it is in, break the two nuts apart, then you should be able to back them off and back the rod out just gripping it with pliers.

there is probably a cleaner way to do it, but that’s the approach that comes to my mind.

[Robert Hayward]

Thank you everyone. Why did I not think of that ???? Back to work.

[Bill Dufour]

After the double nut slips a few time I would take it apart and dip the male part in soldering flux. Screw it back together and heat it with a torch and soft solder it like water pipe. I might use a coupling nut. As long as you can access both sides easy to remove as well.
Bill D

[johnny means]

Or just buy the tool from any supplier for five bucks. I like to cut the handle off and chuck it up in a drill, as turning a few of these guys will get painful real quick.

[Jamie Buxton]

Lee Valley sells a very good driver for threaded inserts: https://www.leevalley.com/en-us/shop/tools/hand-tools/screwdrivers/bits/70791-1-4-20-insert-nut-driver