0800 653 246    treadway.co.nz	
149
Rim Measurements
 ❱PCD, or Pitch Circle Diameter
The PCD is a measurement that describes the number 
of, and spacing between the stud holes in a rim. 
It’s written in the format  x , where 
the diameter is that of the circle that runs through the 
centre of all the stud holes in a rim. 
•	 The diameter is often measured in inches.
•	 There are a range of common PCD sizes, it is advisable 
to know the required PCD of any rim purchased to 
ensure correct fitting to the hub.
•	 Common measurements are: 4x4", 4x4.5", 6x5.5"
METHOD 2
A
1.	 Count the number of stud holes.
2.	Measure the distance between the centre of one 
stud hole and the next closest stud hole, we’ll call 
this measurement A .
3.	Depending on the number of stud holes use one of 
the below formulas:
3 Stud PCD	
diameter = measurement A  / 1.155
4 Stud PCD	
diameter = measurement A  / 0.7071
5 Stud PCD	
diameter = measurement A  / 0.5878
6 Stud PCD	
diameter = measurement A  / 0.5
METHOD 1
CENTRE BORE A
B
1.	 Count the number of stud holes
2.	Measure the centre bore diameter, we’ll call this A .
3.	Measure the distance from the edge of the centre 
bore to the centre of the stud hole, we’ll call this B .
4.	Double the B  value and add it to A  to get your 
diameter (2 x B  + A )
 Watch video
 ❱Measuring the PCD of rims with an odd number of studs 
METHOD
1.	 Count the number of studs
2.	Measure from the centre to the centre of the  
opposite stud or hole.
 ❱Measuring the PCD of rims with an even number of studs
APPENDIX 
| 
TRAILER PARTS & SPARES 
| 
AG HUBS & PARTS 
| 
TUBES 
| 
TYRES 
| 
WHEELS & RIMS 
| 
TIPPING EQUIPMENT 
| 
TRAILER COMPONENTS 
| 
SUSPENSION & AXLES 
| 
TRAILER & BRAKE KITS

View this content as a flipbook by clicking here.