A truck wheel can have the correct diameter, width and stud pattern and still be the wrong fit. One specification that is easy to overlook is the wheel centre bore.
The centre bore is the opening in the middle of the wheel. Its dimensions form part of the wheel's mounting specification and need to be compatible with the vehicle's hub and mounting system.
When comparing 22.5-inch truck wheels, checking the centre bore alongside the PCD, offset and stud-hole configuration can help prevent ordering a wheel that appears correct but does not match the required fitment.
This guide explains truck wheel centre bore size, why it matters and what else to check when identifying a replacement truck wheel.
What Is the Centre Bore on a Truck Wheel?
The centre bore is the large circular opening at the centre of the wheel.
When the wheel is installed, this opening sits around the relevant section of the hub assembly.
Centre bore is separate from the wheel's:
- Diameter
- Width
- PCD
- Offset
- Stud-hole size
Each measurement describes a different part of the wheel.
This means two truck wheels can both be 22.5-inch 10-stud wheels while having other dimensional differences that affect compatibility.
Why Does Truck Wheel Centre Bore Size Matter?
The centre bore forms part of the wheel-to-hub fitment.
A replacement wheel therefore needs to have the correct specifications for the vehicle's mounting system.
Checking centre bore is particularly important when comparing wheels that otherwise appear very similar.
For example, two wheels might both be:
8.25 × 22.5
and both might have:
10 mounting holes
That information alone does not establish that the wheels have identical fitment.
PCD, centre bore, offset, stud-hole configuration and other specifications still need to be checked.
Centre Bore vs PCD: What’s the Difference?
Centre bore and PCD are two different measurements.
The centre bore refers to the opening in the middle of the wheel.
PCD (Pitch Circle Diameter) describes the imaginary circle passing through the centres of the wheel's mounting holes.
For example:
10/285 means 10 mounting holes on a 285 mm PCD.
10/335 means 10 mounting holes on a 335 mm PCD.
Neither measurement should be used as a substitute for the other.
A wheel needs the correct overall mounting specification for the intended vehicle.
Does the Same PCD Mean the Same Centre Bore?
Not necessarily.
Knowing that a wheel is 10/285 or 10/335 identifies its mounting-hole pattern, but it does not provide every other dimension of the wheel.
This is why ordering a replacement based only on PCD can lead to problems.
Before purchasing, compare the complete wheel specification, including:
- Centre bore
- PCD
- Wheel width
- Wheel diameter
- Offset
- Stud-hole specification
- Load rating
- Intended application
Matching one measurement does not automatically mean every other measurement matches.
What Does Hub-Centred Mean?
In a hub-centred wheel system, the wheel is located concentrically using the hub and centre-bore interface.
The centre opening and hub arrangement are therefore important parts of how the wheel is positioned.
This is another reason the centre bore should not be ignored when identifying a replacement wheel.
Truck wheel mounting systems and specifications can vary, so the correct wheel should always be confirmed for the particular vehicle rather than assuming all 10-stud wheels mount in exactly the same way.
Centre Bore vs Stud Holes
The centre bore is the large opening in the middle of the wheel, while the stud holes are the smaller mounting holes positioned around it.
They perform different roles and have separate measurements.
When identifying a truck wheel, you may therefore need to know:
Centre bore – dimensions of the central opening.
Number of mounting holes – for example, 10.
PCD – for example, 285 mm or 335 mm.
Stud-hole specification – the required dimensions and configuration of the individual mounting holes.
All of these can be relevant when confirming wheel compatibility.
Centre Bore on 10/285 Truck Wheels
A 10/285 truck wheel has 10 mounting holes positioned on a 285 mm Pitch Circle Diameter.
Within the Mesh range, this configuration is commonly associated with American truck applications.
However, knowing that a wheel is 10/285 does not provide its complete fitment.
The required centre bore and other mounting dimensions still need to be confirmed against the truck and existing wheel.
Do not order a replacement solely because both wheels are labelled 10/285.
Centre Bore on 10/335 Truck Wheels
A 10/335 truck wheel has 10 mounting holes positioned on a 335 mm Pitch Circle Diameter.
Within the Mesh range, 10/335 configurations are commonly associated with European and Japanese truck applications.
Again, PCD should only be treated as one part of the specification.
When replacing a 10/335 wheel, check its centre bore, width, offset, stud-hole configuration, load rating and application as well.
Does Wheel Size Tell You the Centre Bore?
No.
A size such as 8.25 × 22.5 tells you the nominal width and diameter of the wheel.
It does not tell you the centre bore.
The same principle applies to other sizes within the Mesh range, including:
- 8.25 × 22.5
- 9.00 × 22.5
- 11.75 × 22.5
These dimensions are useful for identifying wheel size, but additional specifications are required to establish the complete fitment.
Centre Bore and Truck Wheel Offset
Centre bore and offset are also separate specifications.
Centre bore relates to the central opening and hub fitment.
Offset describes the position of the wheel's mounting surface relative to its centreline.
Both can be important when choosing a replacement truck wheel.
A wheel could have the correct centre bore and PCD while still having an unsuitable offset for the intended application.
This is why wheel identification should always consider the complete specification.
How Do I Find My Truck Wheel Centre Bore?
The best starting point is the existing wheel's specifications and identifying information.
Look for:
- Manufacturer markings
- Wheel size
- Part number
- PCD information
- Offset markings
- Other stamped or engraved specifications
If the required centre bore cannot be confidently identified from the available information, the wheel or hub should be accurately checked before ordering a replacement.
Avoid estimating centre bore from photographs or visual appearance.
How Do You Measure a Truck Wheel Centre Bore?
Centre bore is measured across the central opening of the wheel.
Because truck wheel fitment requires accurate dimensions, this is not a measurement that should be guessed.
If you are unsure how to obtain the required measurement accurately, have the wheel specification confirmed before purchasing.
It can also be useful to provide the wheel supplier with the existing wheel's markings, part number and vehicle details.
Can a Wheel Have the Correct Stud Pattern but the Wrong Centre Bore?
Yes.
The stud pattern and centre bore describe different parts of the wheel.
A wheel may appear to have the correct number of mounting holes and PCD but differ elsewhere in its specification.
This is exactly why matching a truck wheel by stud pattern alone is not recommended.
The centre bore and other relevant dimensions should also be checked.
How to Check a Replacement Truck Wheel
Before ordering a replacement truck rim, work through the complete specification rather than checking only one or two measurements.
1. Check the Wheel Diameter
Confirm the required diameter, such as 22.5 inches.
2. Check the Wheel Width
Identify whether the wheel is 8.25, 9.00, 11.75 inches or another specified width.
3. Confirm the PCD
Determine the correct stud pattern, such as 10/285 or 10/335.
4. Check the Centre Bore
Confirm the required central opening and hub specification.
5. Check the Offset
Make sure the wheel has the offset required for the vehicle and axle application.
6. Confirm the Stud-Hole Specification
Do not assume all wheels with the same PCD use identical mounting-hole specifications.
7. Check the Load Rating
The wheel must have an appropriate rated capacity for the intended application.
8. Confirm the Axle Application
Establish whether the wheel is required for a steer, drive or trailer position.
Common Centre Bore and Fitment Mistakes
When replacing truck wheels, avoid assumptions such as:
- All 22.5-inch wheels have the same centre bore.
- All 10-stud wheels fit the same hub.
- Matching the PCD means the wheel will fit.
- 10/285 tells you every dimension of the wheel.
- 10/335 tells you every dimension of the wheel.
- A visually identical centre opening must be the same size.
- Wheel offset does not matter if the centre bore matches.
A replacement wheel should be identified using the complete specification.
Frequently Asked Questions
What is the centre bore of a truck wheel?
The centre bore is the large circular opening in the centre of the wheel. Its dimensions form part of the wheel's hub and mounting specification.
Is centre bore the same as PCD?
No. Centre bore describes the central opening, while PCD describes the diameter of the circle on which the mounting holes are positioned.
Does 10/335 tell me the centre bore?
No. 10/335 tells you that the wheel has 10 mounting holes positioned on a 335 mm PCD. Other dimensions, including centre bore, still need to be checked.
Does 10/285 tell me the centre bore?
No. 10/285 identifies a 10-hole, 285 mm PCD configuration. It does not by itself identify the wheel's centre bore.
Can two 22.5-inch truck wheels have different centre bores?
Yes. A 22.5-inch measurement describes the nominal wheel diameter, not the complete mounting specification.
Can I identify a truck wheel using the centre bore alone?
No. Centre bore should be checked alongside wheel diameter, width, PCD, offset, stud-hole specification, load rating and intended application.
What should I do if I don't know my centre bore?
Check the existing wheel's markings and specifications. If the required dimensions remain unclear, have the wheel or hub specification confirmed before ordering.
Find the Correct Truck Wheel at Mesh
Centre bore is only one measurement, but it can be an important part of identifying the correct replacement truck wheel.
Before ordering, confirm the wheel diameter, width, PCD, centre bore, offset, mounting specifications and intended axle application.
Mesh Wheels and Accessories offers a range of 22.5-inch truck wheels across 10/285 and 10/335 configurations, including steel and alloy options.
Browse our truck wheel range or request a wheel quote if you need help identifying the required specification.
