hello everyone, this is my first post. Right now I am trying to figure out which equations to use to solve the following. I will have a block that will a threaded rod through it. This block will be next to another larger block. In between these blocks are going to be metal samples. Now here is the cool part, when I turn the thread via gears and such, the block that is engaged with the threaded rod will move and help deform the separate metal samples till failure occurs. I need to know how much engagement (Le) the block has to have with the threaded rod so failure will not occur. Some helpful givens: -I am using steel -The amount of force needed to break these samples is approximately 300lbs, that is 150 in the opposite directions of the sample.