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. This means from the floor to the attaching surface
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.
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.
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.
Different Materials:
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.
8. 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.
9. Cast Iron Castor Wheels very strong wheels which work well in hard condition where some temperature could be involved for example a powered coaters
10. 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.
11. 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.
13. 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
Castors come in 5 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.
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 on 01296 438208
Quick Guide How To Measure A Wheel
In order to purchase the correct wheel there are some critical dimensions we require to ensure we supply the correct wheel.
Tyre Material – whats the tyre made from.
Still not sure call our technical sales people who will be more than happy to assist.
Adjustable Feet
Adjustable load feet are produced in a wide variety of sizes and styles. Threaded stem are used to fit the foot into your application therefore we need to measure and ensure we have the correct size thread. The feet can also be supplied in a bright zinc finish or stainless steel once again depending on the environment being used in.
Key things when measuiring load feet
Total overall height
Base diameter
Base type: Conical, Bolt down, shrouded non shrouded, Anti-vibration mounted
Thread diameter
Material type
How to attach your foot to an application
Threaded Metal Components – We offer a range of Weld on Nuts, Tee Nuts and Threaded wood inserts, which are ideal for M6, M8 and M10 adjustable feet. Just match up the thread size with the metal component. Tee Nuts and Wood Inserts are ideally used on MDF and solid wood. Pilot holes would need to be drilled for the wood insert.
Threaded Inserts - Threaded Inserts are the ideal way to attach height adjusters, conveyor feet and levelling feet into hollow tubular legs. In order to match the correct threaded insert with the correct adjustable foot, just match the thread sizes, either M6, M8,M10, M12 & M16.
Stainless Steel Weld on Plates – Ideal for stainless steel conveyor feet and are offered in a range of thread sizes and diameters. Great if your application is always getting wet as they won't rust.
1. External Tube Diameter - Measure the external diameter of your tube
2. Tube wall thickness - Measure the tube wall thickness = Outside Diameter – Internal Diameter
All our range of round inserts, square tube caps and rectangular inserts are designed to fit tight with your hollow tube. Each insert has side fins that will retract to ensure a tight snug fit. We can offer plastic inserts to suit varying tube wall thicknesses. Either choose square or round expanders to fit your hollow tube.
Tube wall thicknesses can sometimes be described as a Gauge. Here is a Gauge table that indicates the tube wall thickness and corresponding Gauge number.
Measure your external tube diameter dimensions and have your tube wall thickness, then we can offer you a plastic insert and plastic caps to suit your application.
We offer a range of imperial and metric sizes of tube fittings, so if you are unsure of your size, measure as best you and give us a call so we can offer your the nearests options for you.
