What's the actual application. Are they wheel studs? Or do they bolt the axle flange to the hub (as on a full floating axle)?
This shows them to be 1-3/8" long per the Part number you posted, but is unclear on the application.
If they're axle shaft flange bolts, I wouldn't worry too much about the unthreaded portion, as if they're torqued properly, the axle isn't going to move. I would suggest as bartamos did that you get longer bolts and cut them to the proper length so they don't bottom in the threaded hole in the hub. You won't find a 1-3/8" long bolt at a hardware store or fastener shop. They'll have to be cut anyway. I would suggest grade 8 bolts for adequate strength.