# How do the mechanical elements of a hydraulic press (oil, pumps, valves etc) withstand pressure that can flatten a piece of metal?

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How do the mechanical elements of a hydraulic press (oil, pumps, valves etc) withstand pressure that can flatten a piece of metal?

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Path of least resistance, the liquid has a much easier time moving that tube to flatten thst thing than it does moving outwardly and tubes have high resistance in that way

The mechanical advantage of hydraulics is that extremely high pressures are not necessary to generate a large force.

If you had a piston 1 foot in diameter, a measily 50 psi can generate 5000 pounds of force. Force = pressure times area.

Liquids don’t compress, so by transferring liquid from one cylinder to another they can force the steel rams in one direction.

Pressure= force × area
So if you’re pumping fluid into a cylinder the area is the inside of the cylinder which has more surface area that the press head. So you can push in fluid at a lower pressure over a larger area which is transfered to a smaller area at higher pressure.
Think about 100 pounds in a boot vs 100 pounds on just the heal. Same amount of weight just distributed over a smaller area

Former Press Brake Operator here.
Sometimes they cannot. Certain steels Ike what are used for armor plating are just too tough. Other mild steels are nice and soft. So malleable, you can smoosh them like cookie dough. Diamond plate for example, is made of mild steel, and is designed to be smooshed into dumb shapes for worker’s safety boxes and baskets. That tough stuff that is literally bullet proof is just too strong to bend, without heating it 1000° and killing what it was meant for.

In short, they don’t. Except for the contact point itself.

The machine is designed so that the forces it experiences are spread over a large area, such as the entire inner wall of the hydraulic cylinder. This is actually what the liquid in the pump ia for. It d distributes the force over it’s entire surface.

The target only experiences the force on the end of the cylinder, a much smaller area, for a much larger pressure.

The actual contact surface of the hydraulic press is a thick hardened material, capable of withstanding forces that the target material can’t. Even so, over time it needs repair or replacement.

It’s exactly why knives cut materials, but not your hand. Your force is distributed over the entire handle. The material only gets the very narrow cutting edge.

That cutting edge also feel a lot of force bit it’s a hardened steel, capable of withstanding it for a time unlike the softer portions of the tool.