In the product literature for the X-U I see something that may indicate a max fastened material of 16ga. Is it appropriate to use the X-U for fastening A36 plate steel (either 3/16" or 1/4" thick plate) on to a 3,000 psi concrete slab? Would pilot holes or any other special provisions be necessary?
The X-U fastener can also be used for this application, but there is likely not enough energy in the tool to drive the fastener through the plate and then with adequate penetration in the concrete. Using pilot holes can solve this. The diameter of the fastener is about 0.16", so a pilot hole around that diameter would be indicated. The fastener length should be chosen to allow for the plate thickness plus the desired embedment in the concrete.