Thread: 55t press

As a bolt, the load is carried by the clamp which the bolt provides, the risk of the bolt tearing out or elongating the hole isn't there unless the bolt works loose. In which case the design has to be robust enough to survive until people notice it's loose. This is when the bolts see shear load.

Don't forget the aesthetics too. While a M6 bolt might work, they look a bit lost on a 55ton press. M12 is where they start to look purposeful, M16 is where they start to command respect.
I'd need a picture to understand exactly where you're talking about though.

I think he wants to know what value to give X in this diagram

Thanks Slug, good simple pic and exactly what Im asking. Im sure John understood my question, and he gave a basic answer which I could actually understand. Now I have asked a bit more based on that, it is more complex but well within John (an others) knowledge base.

I can see that there may be some variables, but given the 16mm flat will determine a 8mm center line, both in itself and through the edge of the 75x12, the 1.5 rule may still be valid.

the next question will be since Im going to drill and tap the 16mm and some other areas, what determines thread type (coarse or fine) I personally like fine but nothing other than personal feel.

Originally Posted by Dougal

As a bolt, the load is carried by the clamp which the bolt provides, the risk of the bolt tearing out or elongating the hole isn't there unless the bolt works loose. In which case the design has to be robust enough to survive until people notice it's loose. This is when the bolts see shear load.

Don't forget the aesthetics too. While a M6 bolt might work, they look a bit lost on a 55ton press. M12 is where they start to look purposeful, M16 is where they start to command respect.
I'd need a picture to understand exactly where you're talking about though.

ahhh the old loose bolts. These will be simple to keep check on. See Slugs pic for the particular situation im referring. If you havent clicked on the link to "Dave's Press" I suggest you do. It is well worth it! At this stage Im basing mine on alot of his. I will not have the head beams and table cantilever past one of the uprights. I will not have the ram adjustable height. I will have the ram tram left/right.

no way im putting a M12 into 16mm of material....

Thanks for the pic Slug_burner. Makes it perfectly clear.

Serg, yes I think you're stuck on M6 or M8 there. More M6 bolts will give a better result than fewer M8's.
As you were.

dougal,
One could always mig glue an m16 nut over the m6 bolt head just to give it that ballsy look.
Use lo-hy 316 rods for a nice bronze sheen - for aesthetics of course :-)

S

used M6 X 0.75, fine thread, will be better than M6 X 1.0 coarse thread. Better mechanical advantage, smoother build up of the clamping force, more threads per length etc.

Originally Posted by roverrescue

dougal,
One could always mig glue an m16 nut over the m6 bolt head just to give it that ballsy look.
Use lo-hy 316 rods for a nice bronze sheen - for aesthetics of course :-)

S

An office I used to work in had M24 bolts threaded into 16mm plate in the beams above reception.
It looked wrong enough that about 1/3 of the people who noticed asked if it was real.
Apparently it was.