Technical advice on castors and wheels

Technical advice

Classification of castors and wheels

Basic functional classification:

- wheels

- swivel castors

- fixed castors

Further divisions as regards the type of the bearing, tread, wheel centre and housing are shown in the individual tables.

Load capacity of castors and wheels

When you choose wheels by load capacity, consider the position of the wheels or castors on the vehicle (choose the number K according to the pictures).

The load capacities in the catalogue come from tests to DIN EN 12527 (Castors and wheels, test methods and apparatus). They are dynamic load capacities at an ambient temperature of 20 °C, with further conditions as set out in the standards for each purpose of use.

Depending on the purpose of use, castors and wheels conform to one of these standards:

• EN 840-5:2004 Mobile waste containers, Part 5: Performance requirements and test methods.

• DIN EN 12528:1999 Castors and wheels, castors for furniture, requirements.

• DIN EN 12529:1999 Castors for furniture, castors for swivel chairs, requirements.

• EN 12530:1998 Castors and wheels, castors and wheels for manually propelled institutional applications.

• EN 12532:1998 Castors and wheels, for applications up to 1.1 m/s (4 km/h).

• EN 12533:1998 Castors and wheels, for applications over 1.1 m/s (4 km/h) and up to 4.4 m/s (16 km/h).

Allow for greater dynamic loads and temporary overloads caused by:
• shocks
• falls
• rough or uneven floors
• rolling over obstacles
• higher speed
• side impacts
• higher or lower temperatures
• chemical substances
In these cases do not load the castor or wheel up to its nominal load capacity. Choose a castor or wheel with a greater load capacity instead.

Bearings

Plain bearing: simple to maintain, tolerates blows, suits damp places and slower speeds.

Roller bearing: durable, simple to maintain, tolerates blows, for slower speeds.

Ball bearing: runs easily even at greater loads and higher speeds, suits frequent operation.

Tyre, tread and solid wheel

Solid rubber tyre: smooth run, little vibration in transport, lower rolling resistance than a pneumatic tyre.

Polyurethane tread: high load capacity, low wear, smooth run, unaffected by sharp metal splinters, resistant to hot water and steam.

Pneumatic tyre: very good shock absorption and low resistance on uneven surfaces.

Polyamide and polypropylene solid wheel: unaffected by moisture and many acids, relatively high load capacity, suits smooth surfaces.

Phenolic solid wheel: high load capacity, continuous temperature resistance up to 270 °C. Well suited to bakeries and drying ovens. Do not use phenolic wheels on uneven floors (edges, obstacles) or rough floors.

Cast iron solid wheel: high load capacity, low wear, very high temperature resistance, weaker shock absorption.

Temperature range

The load capacity declared in the catalogue is valid in the temperature range Tn. The operating temperature range To can differ, with a lower load capacity. Load capacity changes with temperature. Some wheel materials tolerate higher temperatures Tt for a short time, but the lower load capacity must be taken into account.

* with a lower load capacity
** on customer request some polyamide and polyurethane wheels can be made from heat-resistant material.