Hello everyone obviously smarter than I. There is an answer I seek, to a project that is willing to be done. I'm considering manufacturing a piece of fitness strengthening equipment that is somewhat unique. There is some sort of equation I'm missing to have an understanding of how to go about the construction, ie which materials to use, and what their capabilities will be. I'm trying to make equipment that is variable in height and length. Without giving away the design, I can say that my need to know revolves around understanding how drilling holes into steel bar/or pipe will degrade said piece. I'm also interested if this degradation in structural integrity and accompanying strength would be offset by filling it snug with a steel bolt of the same quality. An example would be a piece of steel with the strength to handle 1,000 lbs attached to it. Now take a piece of this steel that is circular of 1" OD, and insert a piece that is 17/16 ID. Fit the same holes of 1/4" drilled into each side of each piece, and a 1/4 bolt fitted through all 4 holes. Would it still hold 1,000lbs, IF the bolt was rated for 1,000#'s. Now to add to the mix a few more holes punched every inch running the length of the pipe in a line, which aren't filled with bolts running along the sides of both pipes. Essentially to make the length and/or height of the equipment variable. Would it then be unable to hold the same 1,000# at this point? To what degree would their be loss in strength? Is there a simple equation I can plug in, or would this depend on the overall structure of said equipment? I need to keep it as simple as possible, so let's not envision the whole object (as you have no idea what it is!) and just keep the physics to two pieces of pipe one fitting inside the next snug. Please let me know if further clarification is needed. Thanks.