I'm new to all this but.....

The press frame consists of two posts joined by two beams one above the other. The bottom beam will support the press floor, while the top beam will contain the bottle jack. The top beam will be subjected to a point load from the bottle jack.When the press is loaded it must be able to handle the load fron the bottle jack of 20t or 44,000lbs.

The beam has a free span of 1.2m or 47.25" therefore w=931lbs/inch.

As a starting point i'll consider a beam 8" by 10" in pine(P. radiata, E=1,146,000psi), cypress (C. macrocapa, E=1,146,000) and yellow box (Eucalyptus melliodora, E=1,600,000).

Deflection =5wL^4/(384EI)

Pine and cypress deflection is 0.08".
Box deflection is 0.06".

To this point I havn't had any problems. Its when looking at shear that I'm out of my depth.