Hi All, I'm wondering if somebody could help me with some information. As part of my degree I have to design a set of hydraulically operated guillotine shears which cuts sheet metal 10mm thick and up to 1500 MPa. My question is, when designing shears what kind of formulas should i take into consideration? I have worked out the cylinder pressure/force required to overcome the materials Ultimate Shear Stress of the material, im just after some info on how the angle of the blade holder has an effect and also rake angle.. Any help would be greatly appreciated. Thanks, Chris