How to use clamping kit on Atlas mill table

Thanks everyone for the good, helpful information!
 
On a mill of the atlas size nothing more the twenty ft pounds is plenty. With two clamps that's 40 ft pounds of holding down pressure. Heads on Mower engines only use that and there constant heat and cooling they stay tight .
 
On my Atlas (MFC), I use 3/8-16 bolts with a square head. I have several lengths that I acquired from a now out of business supply house. They have eliminated the punch-through (worry) problem. But still I worry about the "pull-through" aspect of clamping. For the same reason you asked... These are ungraded black iron(unfinished steel), not good grade 5 capscrews. And I watch older machinery for more of different sizes for use on other stuff. They fit the slot very well and I use the clamps and nuts from a clamping kit.

I usually torque to "one snap and a grunt", as opposed to "3 snaps and a grunt" for automotive and mill work. Not much good with real numbers and torque wrenches, unless I'm doing something critical like head work on an automotive engine.

I have have noticed that as I age, that "3 snaps and a grunt" goes more toward the high tolerence of a torque wrench.
 
I'll point out that a square head bolt is more likely to break out the T-slot than is a properly fitting T-nut. It will have less surface area in contact with the upper surface of the slot. The only plus about it is that there is no possibility of screwing the stud down hard against the bottom of the slot. Which can damage even a steel table.
 
wa5cab said:
Don't use a bolt in a T-Nut without confirming that the bolt isn't too long. And to repeat what was written back up the thread, don't let the stud run through the nut.
Click to expand...

May I add ?
Don't use a square shouldered timber coach bolt upside down in the Tee slot either, it will try & rip through the slots , use proper " Tee" nuts that have a quality fit across the slot & depth of the slot and are at least three times the length of the slots width .
 
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Unfortunately, some square head bolts that I've seen in recent years have washer faces. Meaning that the corners of the square aren't actually in contact with the bottom of the slot. The same note is on Page 8 (printed page #) of MMB-5. But for once, I would not do it. Buy proper T-nuts and thin them down to 7/32" instead. And if necessary, grind the sides a little so that they will be a slip fit in the slot. You only need to make a few of them, and they should last forever.
 
wa5cab said:
Unfortunately, some square head bolts that I've seen in recent years have washer faces. Meaning that the corners of the square aren't actually in contact with the bottom of the slot. The same note is on Page 8 (printed page #) of MMB-5. But for once, I would not do it. Buy proper T-nuts and thin them down to 7/32" instead. And if necessary, grind the sides a little so that they will be a slip fit in the slot. You only need to make a few of them, and they should last forever.
Click to expand...

After I read this I had to go and check the 3/8" bolts that I had turned down the heads on. Luckily all mine where flat and do not have a washer face. I have several short ones that I use but I use them to hold something that has a hole in it. A couple of them are jigs that I made to hold something else.
 
Yes, it appears that the washer face is uncommon.
 
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