Just building for one at a time but if need be I’ll modify it to take 2 at a time. I usually don’t buy hay because I make my own rounds or small squares but this year was different.I have 36 in spears with 3 x 3 bales that actually measure 32in wide by 36in tall. They do go all the way thru the bales if you push them all the way in but it is only a problem if you pick wrapped bales from the stack, then you can poke holes in the next bale. I have 3 spears on 2 ft centers 4 ft total, haven't had any problem with 8 ft long bales. I have up rights and if I stab the bottom bale high they do reach up a little ways on the 3rd bale if lifting 3 but normally just do 2 at a time. Are you building it to lift 1 or 2 or 3? you may need more spears when lifting more bales. I have even used mine on 4 x 5 round bales and it worked good and you could pick up 2 with the outer spears if you set them side by side. The neighbor bought a set with 4 spears and they must be about 30 in. It was made for 1 bale as it didn't have uprights, we used 2 x 3 tubing for uprights and on that one we added a cross bar at the top in front of the uprights, it works good for keeping loads nice and straight. 36 in spears also work to move a stack of pallets when stacking in the shed so you don't have to switch to pallet forks, anything shorter probably wouldn't work for that.