Axle has built-in wheel pant stub with 1/4-28 thread.

Axle Bolt Kits
Save time and money with these custom assembled axle bolt kits. Each kit comes complete with all the correctly sized AN bolts, washers, nuts, etc. to properly install the axles to the landing gear.
Gear
Thickness 		Part
No. 		Price
5/8" 5801 $11.00
3/4" 5802 $11.15
7/8" 5803 $11.25
1" 5804 $11.35
1-1/8" 5805 $11.45
  Axle P/N 5018
$49.00 each Axle Nut P/N 5510
$15.50 each Axle Spacer P/N 5710
$4.00 each