Technical Information on Casters
Twin-wheel casters, wheel diameter 32 - 37 - 40 mm = furniture casters
Twin-wheel casters, wheel diameter 50 - 55 - 60 - 65 mm = office chair and furniture casters
Twin-wheel casters, wheel diameter 75 - 80 - 100 mm = furniture casters
We also supply single-wheel and roller casters, caster modules and caster cups as well as chair and furniture glides.
2. Wheel Contact Surface
There are hard and soft wheel casters. Soft wheel casters have a contact surface of non-smearing, abrasion-resistant polyurethane.
The following general rule applies:
- hard wheel casters for soft surfaces, such as carpets and linoleum
- soft wheel casters for hard surfaces, such as tiled, parquet or laminate floors
3. Standard Fixtures
- push fit stem with circlip
- plate fixing
- threaded stem
Please refer to our catalogue for variations of these types of fixings. Special stems can be supplied to the customer's specifications.
4. Brakes and Locking Mechanisms
- un-braked: free-running, without a brake or locking mechanism.
- load-dependent brake: the brake is only applied to the caster when not under load. That means it will not shift uncontrollably when you stand up.
- braked upon charge: the caster brakes the chair or furniture only when under load. That means it will not roll while sitting down.
- wheel-locking: the brake lever locks the wheels.
- complete braking: the brake lever locks the wheels as well as the swivel movement.
5. Load Capacity
The load capacity in kg is approximately the same as the wheel diameter in mm. Please refer to our catalogue for further details.
We recommend the following approximate calculation for furniture with 4 casters:
required load capacity per caster = (weight of furniture + guaranteed maximum loading) x 1/3
6. Neck Diameter
Our casters are available in a variety of neck diameters. This enables optimum matching up to the office chair base. Casters are also available with universal adaptors for special applications.
7. Start, Roll and Swivel-resistance
Before an object on casters can start to move, three resistances have to be overcome by force. The resistances are dependent on the following factors: weight, wheel diameter, load on the casters, material and shape of the contact surface and the type of the floor.
8. Checking the Height
The x-value shown in our catalogue for each type of product has to be added to the y-value of the fixing used. The y-values can be found in the catalogue in tables at the end of that section in the catalogue.
Besides plastics (PA6, TPU, etc.), we use zinc die-casting for certain designs, which can be chrome-plated or powder-coated in a variety of colours.
10. Electrical Conductivity
Casters which conduct electricity are capable of earthing electrostatic charges. Their electric resistance is R = 10^4 Ohm.
The following standards apply:
- EN 12528 for furniture casters
- EN 12529 for braked and unbraked chair casters
Both European standards define the technical requirements, suitable dimensions and requirements for testing.
12. Special Designs
We can also produce casters by custom-designed specifications.
13. Improper Use
In order to ensure a caster's long usage life, the following recommendations should be followed:
- The load must not exceed its load-bearing capacity
- It must not be used on unsuitable surfaces
- The surrounding temperature must not be too high or too low
- Furniture with locking brakes should not be moved forcefully
- It must not be subjected to particularly aggressive agents (cleansing, etc)
- It must not be subjected to improper shock-loading or being dropped
- The casters should not be moved at speeds above 4 km/h (2.5 mph)
- No modifications should be made without consultation.