The axles are 8-32 aircraft grade aluminum bolts. They work fine on an 11 pounder but remember that my struts are designed to be strong but springy. They take most of the landing abuse so the axles don't have to. Springy struts also transfer lower loads into the airframe.

BTW- in case you're wondring how heavy this whole set-up is, the RTF weight of the whole landing gear is less than 5 ounces. Also, the technique I've devised for mounting thegear is very light adding just about another ounce to the the whole gear set-up in a plane. Look that up in my Derivative thread if interested