Hold down clamping kits

[Alcap]

One thing a cheap clamp set has going for it , you won't feel bad if you have to cut/grind/modify a clamp for a special project . I keep cheap wrenches , pliers , screwdrivers for those jobs too

 

[MrWhoopee]

I bought a cheap set off eBay to complete the assortment I had. Despite being advertised as 1/2-13, they were M12x2. Unfortunately, I discovered this after I milled the 22mm hex nuts down to 3/4. Now I have to be careful not to mix them. Someday I'll buy a real 1/2-13 set and give these away.

 

[petertha]

I ended up making a tooling plate from 5/8" aluminum for the table of my mill. It has 3/8-16 tapped holes and .251 reamed holes on offset 1 inch centers.

Are the 0.251" reamed holes so you can insert dowel pins & position parts up against them or something along those lines?

 

[NortonDommi]

I had an employee one time who thought that he was doing us a favor. He noticed that the studs in a brand new clamp kit didn't screw all the way through the T-nuts so he tapped them all through and proudly showed my shop foreman and I what a nice job he did! He was a little disappointed with himself when we pointed out that they are made that way to prevent the stud from jamming the T-nut in the T-slot! Nothing that a couple of strategic wacks with a center punch couldn't cure.

Actually the upset is to prevent the bolt or stud from protruding into to T-slot and jamming but more importantly if a bolt is used to prevent jacking. If you see a slotted table with a hunk broken out of it chances are that someone used a bolt and cranked it down jacking the T-nut out through the top of the slot. Many tons of pressure can easily be generated and cast iron does not like tension.
I found a whole lot of little marks appearing all over my table once and traced it to a cheap set of clamps bought on sale. I had been in a hurry on a job at night and hadn't noticed the finish. Very rough with sharp edges. !/2 hour with a file and buff and all was good. Still miffed about the table.