I bought these about a year ago to build a rack for my firewood.  I used pressure treated 2x4's (x8' length) that I purchased from the local DIY store along with deck screws to hold the lumber parts securely to the brackets.  The parts went together very easily with just a slight bit of trimming with a jigsaw at the end of some of the 2x4's to make them fit into the brackets.  It took about an hour with all the cutting, assembling, and screwing to finish the project from beginning to end.  I could have built a wood rack without these brackets, but I think that without these brackets, it would have either taken more lumber and much, much more time to put together something that is as strong and that can hold as much firewood as a rack built with these brackets.