Hydraulic press table

[drummerdimitri]

I need to buy a piece of steel measuring around 35 cm in width and 60 cm in length to be used as a table to press onto with the full 100 metric tons of force.

There is a 31 cm air gap between the two steel ledges and each of the ledges is around 25 mm thick.

My question is the following: What material and thickness of steel should I get in so that I may apply max pressure without having the plate bend at all?

Should I go for mild steel or some grade of hardox? The latter is much more expensive but it is much harder which is probably a good think for durability stiffer so a thinner piece of steel would do the same job vs mild steel and would weigh a lot less.

I would also like to add some extra thickness in order to be able to face mill the plate flat again after years of use and abuse in case nicks and dings appear on the surface over time.

The piston is 100 mm in diameter.

Any recommendations?

 

[drummerdimitri]

BUMP!

 

[cvairwerks]

For reference, for a 100 US ton press, a set of plates will span a little under 26 cm and are just over 6 cm thick, and they will flex some. As you are spanning about 20% greater distance and about 15% greater load, I would scale up accordingly. An engineer should be able to run the calculations and give you the deflections at that load, based on the material specifications. No matter what material you select, it's going to weigh over 150 kilos.

 

[drummerdimitri]

For reference, for a 100 US ton press, a set of plates will span a little under 26 cm and are just over 6 cm thick, and they will flex some. As you are spanning about 20% greater distance and about 15% greater load, I would scale up accordingly. An engineer should be able to run the calculations and give you the deflections at that load, based on the material specifications. No matter what material you select, it's going to weigh over 150 kilos.

The weight doesn't matter as I have a crane and magnets to lift it.

I just need to know the thickness required that's all.

 

[RoninB4]

I need to buy a piece of steel measuring around 35 cm in width and 60 cm in length to be used as a table to press onto with the full 100 metric tons of force.

-I'm guessing that you're wanting a bolster plate?

There is a 31 cm air gap between the two steel ledges and each of the ledges is around 25 mm thick.

-Photo or drawing would help define what you mean by "ledges".

My question is the following: What material and thickness of steel should I get in so that I may apply max pressure without having the plate bend at all?

-Will this be for stamping/perforating or for sheet metal bending/forming? What sort of tooling will go into the press? What sort of work will you be doing?

Should I go for mild steel or some grade of hardox? The latter is much more expensive but it is much harder which is probably a good think for durability stiffer so a thinner piece of steel would do the same job vs mild steel and would weigh a lot less.

-Hardness is mostly for abrasion resistance, If I understand what you're wanting to do the bed/bolster will not experience any abrasion. The tooling you mount in the press will need abrasion resistance. Stiffness is the same for all steels until it deflects/bends past the point of deformation. This is a factor for the work material and not the bed/bolster. The added cost of Hardox for abrasion/deformation resistance doesn't seem to add a benefit if I understand what you want. If I don't understand then ignore most of my posting.

I would also like to add some extra thickness in order to be able to face mill the plate flat again after years of use and abuse in case nicks and dings appear on the surface over time.

-Added thickness may/may not be worth the cost, a lot depends upon what you have available in your country. You haven't mentioned whether you want "T-Slots" (for mounting tooling) or not. Used bolster plates are available in this country, perhaps not readily available in yours. Nicks and dings are fairly minor damage that don't really matter, regular use of a good abrasive stone after tooling is removed keeps the displaced metal on the bed/bolster flat. What is a concern is whether the bed/bolster remains flat/planer over the years.

Any recommendations?

-Have you done any research on bed/bolster plate design? There are formulas for calculating what you need. Report what you find.

 

[drummerdimitri]

-I'm guessing that you're wanting a bolster plate?

-Photo or drawing would help define what you mean by "ledges".

-Will this be for stamping/perforating or for sheet metal bending/forming? What sort of tooling will go into the press? What sort of work will you be doing?

-Hardness is mostly for abrasion resistance, If I understand what you're wanting to do the bed/bolster will not experience any abrasion. The tooling you mount in the press will need abrasion resistance. Stiffness is the same for all steels until it deflects/bends past the point of deformation. This is a factor for the work material and not the bed/bolster. The added cost of Hardox for abrasion/deformation resistance doesn't seem to add a benefit if I understand what you want. If I don't understand then ignore most of my posting.

-Added thickness may/may not be worth the cost, a lot depends upon what you have available in your country. You haven't mentioned whether you want "T-Slots" (for mounting tooling) or not. Used bolster plates are available in this country, perhaps not readily available in yours. Nicks and dings are fairly minor damage that don't really matter, regular use of a good abrasive stone after tooling is removed keeps the displaced metal on the bed/bolster flat. What is a concern is whether the bed/bolster remains flat/planer over the years.

-Have you done any research on bed/bolster plate design? There are formulas for calculating what you need. Report what you find.

Not a bolster table, just a steel plate to press thing onto so It shouldn't have a hole in the middle or any T slots for tooling.

I've attached a picture of what the press table looks like. As you can see, there is a large air gap and the steel plate I need will have to sit on the edges and bridge said gap.

Hope I made myself clear.

 

[speed bump]

I can't remember if our 100 ton press plates are 2" or 3" thick steel with reinforcement welded onto the bottom. I would probably go 3" minimum if you aren't going to reinforce them though.

 

[RTM]

Color me stupid about big presses like that, but it seems for closing a big gap, an I beam pair would be more appropriate, then place smaller thinner plates the size of the work on top of that. Wouldn't that be better than a multiple inch thick piece of metal if the problem is a huge gap to be closed?

 

[ipgenie]

I'm building a 50 ton press with similar dimensions. I went with a 2in (50cm) mild steel plate for the table. I have drilled and threaded some holes for mounting fixtures or hold down clamps.
I didn't use any calculations, but I'm basing the design on another press a neighbor has and his 2in plate has been working well for several years. His cylinder is only 40 ton so a little smaller.
I won't have my hydraulic cylinder for another month or so, it's being built, but I don't expect any issues. I won't be pressing 50 tons very often (maybe never) so it's probably overkill.

100 tons is a lot of pressure. You'll probably need a pretty thick plate.

 

[drummerdimitri]

For those of you who may face the same problem in the future, I ended up getting a 5 cm thick plate of Hardox 450 measuring 60 cm x 40 cm and under max tonnage, I am only getting a 0.5 mm deflection at the middle with 0 plastic deformation which is an excellent result and I couldn't be more pleased. Only issue is the fact that it did cost me 500 $ but the pressing table Stenhoj sells was 1600$ so I did save a ton of cash by going this route.