Not sure what you call them. But I will be building 2 this size and 1 smaller. Between the 3 I think I can get close to 2 cord stacked. Anyhow here are some pics. I bolted some of it with 3/8 x 4 bolts and some of it is screwed with torq head epoxy coated deck screws. I even notched it out. I must say I really like these torq head screws. 10 thousand times better then Philips. I think I want to add a cross piece on each end but other then that I think it will hold. What do you all think?