Centre Bore Machining

What is centre-bore machining?

It’s a CNC enlargement of the wheel’s centre hole so the wheel seats perfectly on your vehicle’s hub. A hub-centric fit stops vibration, protects studs and gives a factory-smooth drive. (If your wheel’s bore is larger than the hub, we’ll use spigot rings—you can’t “shrink” a bore with machining.)

When you might need it

• You’ve bought aftermarket or second-hand wheels and the bore is too small for your hub.
• You’re swapping wheels between brands (e.g., VW → Toyota) and sizes don’t match.
• You want to replace lug-centric fitment with a proper hub-centric fit to cure shakes at motorway speeds.
• A previous repair or coating has closed up the bore tolerance.

We’ll measure first and confirm there’s enough material for a safe enlargement. If a wheel isn’t suitable, we’ll say so and suggest options.

What we do

1. Assess & measure – We confirm hub size, check wheel thickness and face profile, and record current bore tolerance.
2. Set & clock – Wheel is mounted and dial-indicated so machining is perfectly concentric to the mounting face.
3. CNC machine – Bore is cut to the target hub size with the correct surface finish and lead-in chamfer.
4. Deburr & clean – Edges are broken neatly; paint/powder is protected or touched-in as required.
5. Test-fit & balance – We test on a reference hub and recommend rings if you’ll run a larger universal bore across multiple cars.

Typical turnaround: single wheels often same day; full sets 24–48 hours. Need to keep moving? Ask about loan wheels (subject to size/availability).

Important notes

• We enlarge centre bores; we don’t weld/add material to make them smaller—use spigot rings for that.
• Centre-bore machining doesn’t change PCD, offset or stud seat type.
• We won’t machine wheels that don’t retain adequate material around the bore after enlargement. Safety first, always.

Why our Grey Lynn workshop

• CNC accuracy for a true hub-centric fit—no “wobble bores” from hand tools.
• Measured, documented tolerances so you know the job’s been done right.
• One-stop service: if a wheel also needs straightening, TIG repairs, paint or powder, we can handle it here.
• Local, independent crew—straight talk, no surprises.

FAQs

Will it weaken the wheel?
Not when done within safe limits. We measure first and only proceed if enough material remains after the cut.

Do I still need hub rings?
If we machine to your exact hub size, no. If you plan to run the wheels on multiple cars, we can machine to a common larger size and supply rings.

Can you reduce a centre bore?
No—metal removal only. To “shrink” a bore we use spigot rings (plastic or alloy).

Does this fix vibration?
If vibration is from an off-centre fit, yes. We still recommend dynamic balancing after fitment.

Ready for a proper hub-centric fit?

Send a couple of photos and your hub size (or car make/model), or pop by 6 King St, Grey Lynn. We’ll confirm suitability and quote fast.