My questions are: - Will a proposed bracket be able to support 7500 lb. without undue or permanent distortion or failure? - Can the proposed dimensions be improved? The bracket will be attached to a large tree and will support one end of the 4x6 redwood swingset beam. (On the other end: an A-frame of 4x4s.) The attachment includes bracket sketches and a rough drawing of the swingset. Appropriate brackets are not commercially available, so we need to get one made. Constraints: - For the tree's health, one bracket attached by one big bolt is better than several brackets. - To allow for tree movement the beam is not fixed to the bracket, and the bracket is wide enough to allow side-to-side slippage. To keep the beam from popping out the top, the bracket is oversized in height and will have four small additional holes to hold cables or bolts across the top. - The biggest force on the bracket will stem from use. Based on information on other websites, I've calculated that if 220 lb of children swinging in unison on an 8' radius fast enough to do a 360 around the beam, the centripetal force at the bottom of the swing will be less than 1400 lb. The beam and swing equipment will likely be under 100 lb. A 5x safety factor yields 7500 lb. Clearly the bracket will get a lot of movement in several directions. - The bracket will likely be 1/4" stainless steel -- could be cold- or hot-rolled plate but custom galvanizing costs $$$. Presumably the bracket will be made of plate welded at the corners. The proposed bracket will have a J shape with dimensions (assuming 1/4" steel): - Bottom 5.5" (x 6"?) - Short vertical side 8" high (x 6"?) - Tall vertical side of 10" high (x 6"?) The least-certain dimensions are the width of the bracket (i.e., parallel to the long dimension of the bracket), and the thickness of the steel. For example, would we be better off with a bracket of 6" width and 1/4" steel, or 4" width and 3/8" steel? Is the whole thing over- or under-engineered? I will be grateful for any help you can give me. Thanks!