Castor wheel diameter and load capacity: what 1,307 AVO castors show

By Furniture Components (analysis of our own catalogue) · 2026-10-31

A castor’s load rating is the number people ask about first, and the one catalogues bury in a SKU table. Our castor catalogue holds 1,897 castors; 1,307 of them, all from the Italian maker AVO, list both a wheel diameter and a dynamic load capacity, so we can see how the two move together. Everything below describes that AVO range. Other makers rate castors differently, so treat the figures as an orientation, not as a standard.

Reading the rating: daN, dynamic and static

AVO gives loads in daN (decanewton). 1 daN is 10 N, which is about 1.02 kg of weight, so you can read daN as “roughly kilograms” for furniture work. Two ratings appear:

  • Dynamic load capacity: what one castor may carry while the furniture is being rolled.
  • Static load capacity: what it may carry standing still.

The static figure is the higher one in practice: in 1,214 of the 1,215 AVO castors that list both, static is equal to or above dynamic. The median static value is 1.33 times the dynamic one. Size the castors by the dynamic value, since furniture on castors is meant to move.

Both ratings are per castor. A cabinet on four castors shares its weight between them, and in practice one castor often carries more than a quarter of it on uneven floors, so we would not choose castors that sit right at the limit.

Dynamic load by wheel diameter

Wheel diameter Castors Dynamic load, lowest Median Highest Static, median
30 mm 33 15 daN 20 daN 20 daN 30 daN
35 mm 58 10 daN 10 daN 15 daN 20 daN
40 mm 160 15 daN 17.5 daN 30 daN 20 daN
50 mm 206 20 daN 20 daN 45 daN 30 daN
60 mm 236 40 daN 50 daN 60 daN 70 daN
75 mm 9 55 daN 55 daN 55 daN 70 daN
80 mm 210 55 daN 60 daN 70 daN 80 daN
100 mm 209 60 daN 70 daN 80 daN 90 daN
125 mm 186 70 daN 90 daN 100 daN 120 daN

Three things stand out:

  1. Below 50 mm the range is light-duty: nothing under 50 mm is rated above 30 daN.
  2. There is a step between 50 and 60 mm. The median dynamic load goes from 20 daN to 50 daN. It is not an artefact of mixing series: in AVO’s series 220, for instance, the 50 mm castors are rated 20 daN and the 60 mm ones 50 daN.
  3. From 60 mm up, the load keeps growing, from a median of 50 daN at 60 mm to 90 daN at 125 mm, where the highest rating is 100 daN per castor.

Wheel material changes the number

At the same diameter, the wheel tread matters. Median dynamic load of AVO castors by material (only materials with at least 5 castors at that diameter):

Diameter Solid rubber Non-marking rubber Rubber Synthetic rubber Polypropylene
50 mm 40 daN 30 daN 20 daN 20 daN 20 daN
60 mm 60 daN 60 daN 50 daN 50 daN 50 daN
80 mm 70 daN 70 daN 60 daN 55 daN 55 daN
100 mm 80 daN 80 daN 70 daN 60 daN 60 daN

Solid and non-marking rubber wheels carry 10 to 20 daN more than synthetic rubber or polypropylene wheels of the same size. This is an association in the catalogue, not a proof of cause: the materials are not spread evenly over the series, and a series also changes the bearing and the fork. It does mean that comparing castors by diameter alone can mislead. Compare the rating itself.

Non-marking wheels leave no dark streaks on light floors; AVO lists non-marking rubber for 153 castors and non-marking synthetic rubber for 15 more.

How the castor attaches

Of the 1,489 castors in the catalogue that state a mounting type (all makers), about two thirds use a stem:

Mounting Castors
Stem 1,008
Bolt hole 159
Top plate (fixed or swivelling) 285
Other (hole, bracket, socket, expander, axle) 37

The stem comes in two main forms, and they split the range almost exactly in half. Of the 901 castors with a stem type, 444 have a threaded axle (screwed into a threaded insert) and 440 have a rubber expander (pressed into a drilled hole and held by the expander). Check the hole in the furniture first: a threaded axle needs an insert, an expander needs a plain bored hole of the right diameter.

Choosing, in four steps

  1. Add up the weight of the furniture and what it will hold, divide by the number of castors, and add headroom.
  2. Pick castors whose dynamic rating is above that figure. Filter the castor catalogue by diameter, then compare the rating, not the size.
  3. Match the mounting to what the furniture offers: stem with threaded axle or expander, or top plate.
  4. Choose the tread for the floor: non-marking for light floors, solid rubber where you need the higher rating.

About the data

The sample is the 1,307 AVO castors in the catalogue that list both diameter and dynamic load, taken from AVO’s furniture-castor series tables. Mounting counts use all 1,897 castors. Figures are the manufacturer’s own ratings and have not been tested by us.

Sources