At Monroc, each axle is identified by a reference code that contains essential technical information. Understanding this coding system helps you quickly choose the right model for your application. Here’s how to decode a typical reference, for example: 505F.
50: The Square Dimension
The “square” refers to the cross-section of the axle body, expressed in millimetres. In our example, 50 means the axle has a 50 mm section.
This dimension directly affects the load capacity and the overhang:
- The larger the square, the more the axle can handle heavy loads or intensive working conditions.
- A smaller section is more suitable for light-duty applications or low-tonnage vehicles.
The choice of square dimension depends on the load to be transported, the type of trailer, and the terrain (field, road, slope, etc.).
5: The Number of Studs
The next digit in the reference, here 5, indicates the number of studs used to secure the wheel to the axle hub.
The number of studs allows for increasingly larger wheels. More studs also mean greater load capacity for the hub.
However, to correctly identify the setup, it’s also important to know the stud diameter, thread pitch, and the PCD (Pitch Circle Diameter) — the diameter of the circle passing through all the studs.
At Monroc, here are the available configurations depending on the number of studs:
- 4 studs: 14 mm × 1.5 mm, PCD from 85 to 130 mm
- 5 studs: 16 mm × 1.5 mm, PCD from 94 to 140 mm
- 6 studs: 18 mm × 1.5 mm, PCD from 160 to 205 mm
- 8 studs: 18 mm × 1.5 mm, PCD from 220 to 275 mm
- 10 studs: 22 mm × 1.5 mm, PCD from 280 to 335 mm
It is essential to check that both the number of studs and the PCD match your wheels to avoid any assembly issues.
F : Hub Type
The letter F at the end of the reference indicates the type of hub fitted on the axle. Here are some common examples:
- F = made of GL 250 cast iron, the most economical option, available with 4 or 5 holes. Used in basic handling applications.
- A = made of forged steel, the most resistant, but also the most expensive. Used in soil working and aerial platforms. Gradually being replaced by X-type hubs.
- X or XR = made of FGS cast iron (spheroidal graphite cast iron), a material similar to steel, more affordable, and increasingly used.
- MF = Monobloc Freiné (monoblock braked). The hub includes a brake drum. Suitable for soil working, transport, and handling with low load and speed.
- XF = X-type braked hub. Suitable for soil working, transport, and handling, with high loads and all speed ranges.
At Monroc, each hub corresponds to a precise industrial standard (PCD, diameter, applications…).
Choosing the right hub ensures perfect compatibility with your wheel and guarantees smooth and safe rotation.
In Summary
The 505F reference means:
- 50 mm square section → axle body size, related to load capacity and overhang
- 5 studs → 16 mm × 1.5 mm with a PCD between 94 and 140 mm
- F → GL 250 cast iron hub
This simple coding system helps you save time, avoid errors, and order the axle that best suits your needs.
Not sure about a reference? Need a custom axle or expert advice?
Contact the Monroc team — we’re here to help.
