Our part numbers for Axles are assigned in accordance to the capacity, bolt pattern, type of brakes (if any) and type of spindle used. When ordering axles, the following information should be helpful to you.
EX: 20545I-ST-EZ 2,000 lb., 5 on 4 1/2 Idler Straight with E-Z Lube
20 / 545 / I / ST / EZ
20: The first group of digits represent the capacity (20 = 2,000 lb. capacity)
545: The next group represents the number of studs and the bolt pattern of the studs (545 = 5 on 4 1/2", 655 = 6 on 5 1/2", 865 = 8 on 6 1/2", etc.)
I: This tells you which type of brakes are used, if any. (I = Idler, E = Electric, H = Hydraulic, HFB = Hydraulic Free-Backing, A = Air)
ST: This tells you which type of spindles are used (ST = straight, 4D = 4" Drop)
EZ: Any other options ( EZ = E-Z Lube Spindle, SPR = Springs Mounted)