Re the above, here's what I have but there's no way to connect a gauge to the top of the ram as per @Red'n'Black 's example.
So I'm thinking a T-piece between the hose & body with a gauge mounted there? I Googled "hydraulic T-piece and a bewildering selection came up - don't want to buy something which isn't suitable....., so any recommendations?
Also, what pressure [in bar] gauge would I need to take 10 tons? Thanks.
Can't help with the fittings but to answer your second question:
Measure the piston diameter, from this you can work out the area. Then ten tons divided by this number gives you the pressure.
E.g say the piston diameter is 1½ inches.
Half this is ¾ inch.
¾ squared times π is 1.767 square inches.
10 tons is 22,400 lbs.
So pressure is 12,676 psi or about 875 bar.
That sounds quite high so the piston is probably bigger than my first guess.
If you want the gauge to read in tons you'll obviously need a custom scale made.