Some of the loader bolts are SAE. Generally speaking, the loader bolts that are screwed into the tractor are all metric, but many of the bolts that hold the loader's parts together are SAE. Or that's the way a lot of it used to be, may all be metric now on the LA525 FEL.
To my knowledge, every single bolt on the L3301 and L3901 (and most other Kubota tractor) is metric, including the wheel studs, nuts, and bolts. Lot of times a bolt or nut might be 24mm, but a 15/16" fits pretty good. 22mm=7/8". 19mm=3/4". 17mm=11/16". 16mm=5/8". 14mm=9/16". 13mm=1/2". 12 and 10mm interchange with nothing but 11mm is close to 7/16". 8mm=5/16". As said, almost every bolt (at least that I know of) on the tractor is metric, but sometimes an SAE wrench or socket will fit it in a pinch. And occasionally if you get a rounded metric hex, an SAE can sometimes fit tighter on it, helping to get it out. Used that trick a bunch of times!
Back hoe (BH76) bolts are usually SAE and metric mixed.
