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Quick Guide How to Measure and Select a Castor

In order to purchase the correct Castor there are some critical dimensions we require to ensure we supply the correct wheel.

  • Use an accurate measuring devise.

 

  • Measure the total overall height of the castors means from the floor to the attaching surface

 

 

  • Wheel Diameter – this is the distance across the wheel from edge to edge

 

  • Top Plate Fitting the most common type, this is where the castor has four holes on a mounting plate enabling the castor to be bolted or screwed to an application- measure the outer plate edge to edge then the centre of the mounting holes

 

  • Bolt Hole Fitting: enabling a bolt or expander to be used to secure the castors to the Application.

 

The information above will give our technical sales people the basis to take your enquiry forward if you wish to continue the selection process unaided please read below.

 

Health & Safety:

The correct castor must be selected for the require application, cutting corner or trying to save money with cheaper or lighting loading carrying products is extremely dangerous and could cause manual handling injuries. Safety must come first!

 

Castor Selection Criteria

 

Load Capacity

Load Capacity are calculated in two methods depend on the anticipated type of load.  First establish if the loads are Liquid or Solid then apply the following:

(All of our advertised load ratings are based on the assumption that the floor surface is level and compact with no obstructions)

 

Liquid Loads:  If the load consist of liquids our calculation considers that the load can move  and could be over just two castors at one time:

 

Weight of  Application including Trolley

Load capacity of castor   =        ———————————————————-

2

 

Solid Loads:  Working to the principle that the application might not be parallel with the ground if the ground surface is uneven then only three castors will be supporting the load.

 

 

Weight of Application including Trolley

Load capacity of castor   =        ———————————————————-

3

 

Wheel Diameter

The basic principle to work to is that the Larger the wheel diameter the less resistance it requires to move and therefore a consideration at the design stage for any application using castors, if regular

movement is required.

 

Wheel Types

Before Selecting a wheel it is important to determine if the wheel material is compatible with the chemical environmental conditions, the temperature and humidity, all of which effect the wheels operation.

Wheels are available in a large variety of materials all of which are suitable for different environments and working condition.  Basic Principles applied:   The Harder a Wheel Tread the Easier the wheel will move and the less resistance to start motion.  The Strongest wheel are Steel Wheels which will carry the highest loads and with-standard the worst condition however they will damage floors and be noisy.

 

  1. Nylon Wheels offer the cheapest solution for a standard wheel, however liable to skid if obstructed buy small objects on the floor.
  2. Polyurethane tyred wheels with Nylon Centres are a good all round wheel they carry good loads, will not mark or damage floors.
  3. Grey Rubber Castor Wheels with Nylon Centres offer a non marking light weight solution general material handling application.
  4. Grey Rubber Tyred Steel centre castor Wheels offer a non marking light weight solution general material handling application the steel centre enables the wheel to handle higher shock impact loads.
  5. Aluminium centre Black Elastic Rubber Tyred Castor Wheels the elastic rubber enables with wheel to carry high weight loads whilst the Aluminium centre will dissipate the heat from the bore with greater ease.
  6. Black Rubber Tyre Steel Castor Wheels offer a light weight solution general material handling application the steel centre enables the wheel to handle higher shock impact loads.

7.Blue Elastic Rubber Castor Wheels this is a non marking  elastic rubber which  improves the load rating of the wheel.

  1. Cast Iron Centre Polyurethane tyred Castor Wheels this is the most common wheel used in heavy duty applications the polyurethane offer high load capacity and the cast iron core with Ball Bearing bore offers a robust core to handle the loads.
  2. Cast Iron Castor Wheels very strong wheels which work well in hard condition where some temperature could be involved for example a powered coaters
  3. Height Temperature Resin Castor Wheels a perfect solution where the wheels need to with standard high temperatures for periods of time most commonly found in Bakeries.
  4. Aluminium centre Polyurethane tyred Castor Wheels this is the most company wheel used in heavy duty applications the polyurethane offer high load capacity and the Aluminium core will dissipate the heat build up better, this wheel offers a lighter unit weight compared to the cast iron core. Important if you forward applications via couriers.

12.Pneumatic Tyred Castor Wheels a great solution if your application needs to work over rough terrain.

  1. Solid Rubber Castor Wheels standard Trolley wheels used in many applications offer reasonable weight loads and large wheel diameters.

 

 

 

Bearings

 

Plain Bore 

Normally part of the moulded wheel or a nylon bush may have been inserted so the wheel will run directly on a shaft or axle.

 

Needle Roller Bearings

A cage holds steel roller together (needles) this will be found in the bore of wheel measure as the final required bore.  Needle roller bearings will reduce friction between the axle or shaft and the wheel.

 

Ball Bearings

Precision Steel Balls encapsulated in a steel cage will reduce the friction between the wheel and axle of shaft – best suited for very high loads

 

 

Castor Housings Types

 

Castors come in three main types:

 

Top Plate Swivel Castors: 

Four Hole Fixing Points on a Mounting Plate this Style of Castor will Swivel 360 degrees.

 

Top Plate Swivel Braked Castors:

Four Hole Fixing Points on a Mounting Plate this Style of Castor will Swivel 360 degrees complete with a locking system to brake the Wheel and the Swivel Motion

 

Top Plate Fixed Castors:

Four Hole Fixing Points on a Mounting Plate this Style of Castor is Rigid and will only travel in one direction.

 

Top Plate Swivel Directional Lock Castors:

Four Hole Fixing Points on a Mounting Plate this Style of Castor will Swivel 360 degrees complete with a Directional locking system which enables the directional of travel to be locked into one position (this does not lock the wheel or swivel)

 

Top Plate Swivel Directional Lock Braked Castors:

Four Hole Fixing Points on a Mounting Plate this Style of Castor will Swivel 360 degrees complete with a Directional locking system which enables the directional of travel to be locked into one position complete with a locking system to brake the Wheel and the Swivel Action

 

Bolt Hole Castors:

Single Fixing Point Bolt Hole Castors will Swivel 360 degrees.

 

Bolt Hole Braked Castors:

Single Fixing Point Bolt Hole Braked Castors will Swivel 360 degrees and Brake the Wheel and Swivel Action.

Swivel Radius

The distance from the centre of the castor head fitting to the outside of the wheel is known as swivel radius and is very important to ensure your castor does not foul on your application when rotating 360 degrees.

Speed

Castors are designed to travel at 4kph , if your application is going faster then please talk to our technical sales team

 

 

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