Custom Service  ·  Made to Order  ·  UK-Machined

Your bolt pattern.
Any conversion.
Machined to spec.

Custom PCD adapters and hub adapters precision CNC-machined from 6082-T6 aluminium. Any bolt circle. Any centre bore. Any thickness.

±0.02mm Machining tolerance
2–3 wk Typical lead time
Grade 10.9 Fastener hardware
Brightstone Engineering custom PCD adapter — precision CNC machined in the UK

Ready to enquire?

Send your hub and wheel specs below or message us on WhatsApp. Most quotes returned within 24 hours.

Get a quote — fill in the form
contact@brightstoneengineering.com
Pricing

Two adapter types. Clear starting prices.

Hub / centre bore adapter
Pair £149
Full set of 4Best value £229
£57.25 per adapter · save £69 vs 2 pairs

Same bolt pattern, different centre bore — e.g. 5×114.3 66.1 → 5×114.3 72.1.

PCD conversion adapter
Pair £229
Full set of 4Best value £299
£74.75 per adapter · save £159 vs 2 pairs

Bolt pattern conversion, same stud count — e.g. 5×112 → 5×120, 4×100 → 4×108.

Prices shown apply to adapters up to 128mm PCD, machined from 152mm raw stock. Larger PCDs need larger, more expensive raw stock, so prices rise above this — get in touch for a quote on your fitment.

What we make

Any bolt pattern. Any hub. Machined here.

If your wheels don't match your hub — or you're building something no off-the-shelf part covers — we machine the wheel adapter from scratch. Some people call it a hub adapter, bolt pattern adapter, bolt-on spacer, custom wheel spacer, or rim adapter — it's the same part. Every job starts with your measurements and ends with a part that fits first time.

PCD conversion
Different bolt circles between hub and wheel. e.g. 5×112 → 5×120, 5×120 → 5×112, 4×100 → 4×108, or any combination.
Hub to wheel fitment
Fitting aftermarket wheels where the bore, PCD, or offset doesn't match without re-drilling either component.
Motorsport & custom builds
One-offs and short runs for track cars, kit builds, and restorations where no standard part exists.
Offset & stance correction
Adding thickness to push wheels out for a flush-fitment stance, with or without a PCD change. Combine conversion and spacer function in one part.
Brightstone Engineering custom PCD adapters CNC machined adapter
Specification

What's included with every adapter

6082Aluminium grade
±0.02Tolerance (mm)
10.9Hardware grade
5–50+Thickness range (mm)
3–8Bolt patterns
UKMachined in-house
Material6082-T6 or 6061-T6 aluminium billet
MachiningCNC milled in-house for precise, repeatable fitment
Tolerance±0.02mm across all bores and bolt patterns
Bolt patterns3, 4, 5, 6 or 8 stud — any PCD
Thickness5mm up to 50mm and beyond, made to your exact spec
Centre boreMachined to match your hub, so the adapter centres precisely on the vehicle with no play
HardwareGrade 10.9 high-tensile steel studs or bolts
FinishBlack anodised, silver anodised, or Cerakote — anodising and Cerakote finishes are charged as an additional cost on top of the base price
EngravingLaser logo marking available
Lead time2–3 weeks from confirmed specification

Every adapter is machined to fit the hub it's being made for, so it locates precisely on the vehicle with no play. This is why the parts run without vibration.

Recent builds

Fitments we've solved

BMW M5 F10 → aftermarket BBS wheels
PCD conversion adapter to run BBS wheels not originally available in the M5's bolt pattern.
Porsche 911 (997) → Ferrari wheels
Cross-brand PCD conversion, matched to the 911's hub and centre bore.
VW Transporter T5 → Mercedes AMG wheels
PCD conversion adapter for a commercial-to-passenger wheel swap.
Classic Mini → modern 4×100 wheels
Bolt pattern conversion opening up the classic Mini to current wheel fitments.
BMW E46 track car → flush fitment
15mm front / 20mm rear spacers for perfect fitment on a track-prepped 3-series.
Classic Land Rover → modern wheel conversion
Hubcentric spacers with a custom bore to run modern wheels on an older hub design.
Modern hot hatch → flush fitment
12mm all-round spacers for a flush fender-to-wheel stance, no clearance compromises.
Process

From enquiry to fitted adapter

01
Send your measurements
Hub PCD, wheel PCD, centre bores, thread pitch, and desired thickness. Use the form below or WhatsApp — photos of the hub face help.
02
We confirm the spec and price
We check fitment, flag any clearance issues, and send a fixed quote within 24 hours. No obligation.
03
Machined in-house
Your adapter is CNC-programmed and machined from billet aluminium in-house. No outsourcing. Lead time 2–3 weeks.
04
Finished and dispatched
Anodised or Cerakote coated and sent with Grade 10.9 hardware. Check every bolt against your car before fitting.
FAQ
Are these road legal in the UK?
Yes. When installed correctly with suitable wheel hardware that has been checked against the car, CNC-machined PCD adapters are road legal.
How do I find my PCD?
For 4-bolt patterns, measure straight across between two opposite bolt holes. For 5-bolt (or any odd-numbered) patterns, measure from one bolt hole to the hole two positions away, not the adjacent one. Not sure? Send us your vehicle details and we'll confirm it before manufacturing.
What do I need to do after fitting?
Re-check all bolts after the first 100 miles, then periodically thereafter. Clean off road salt and debris regularly, especially over winter, and inspect for wear at each service.
Are wheel adapters safe?
Yes, when properly designed, machined to tolerance, and fitted with bolts that have been checked against the car for correct thread, seat and full thread engagement. Every adapter is CNC-machined in-house from certified 6082-T6/6061-T6 billet with Grade 10.9 hardware — the same standard we'd use on our own cars.
Can you make adapters for vans and commercial vehicles?
Yes — we've built PCD adapters for platforms like the VW Transporter T5 to run passenger-car wheels, and take on Transit and other van conversions on request. Send your hub and wheel specs and we'll confirm fitment.
Can you match rare or unusual fitments?
Yes. If it's a known bolt circle or we can get the measurement, we can machine to it. This includes old classics, Japanese imports, American truck fitments, and bespoke race setups.
Do you do bulk or trade orders?
Yes. We supply UK and EU companies with short-run batches. Get in touch with volumes and we'll quote accordingly.
What information do I need to send?
Hub PCD and centre bore, wheel PCD and centre bore, thread size and seat type (ball or conical), and how thick you want the adapter. If you're unsure of any of these, send photos and we'll work it out with you.
Get a quote

Tell us your spec.
We'll do the rest.

Send us the details below. The more precise your measurements, the faster we can confirm the design and price. Most quotes returned within one working day.

Fill in the quote form below Brightstone Engineering — Precision Made in England
Before you fit — your responsibility

Check your bolts before fitting

We make every effort to send the correct bolts for your vehicle, but vehicles vary by model year, market, trim and previous modifications — we can’t see what is fitted to your car. It is the responsibility of the buyer and whoever fits these parts to check every bolt against the car before use. Do not fit any bolt you have not checked, even if it came from us.

This is a bolt-to-bolt adapter, so there are two separate bolted joints, and both must be right. The bolts that hold the adapter to the car and the bolts that hold the wheel to the adapter each need the correct thread, the correct seat and full thread engagement.

Joint 1 — adapter to car

  1. Measure a bolt from your car.Remove one of your existing wheel bolts and note its thread size, pitch, thread length and seat type.
  2. Match the adapter-to-hub bolts to it.They must be the same thread size and pitch as your hub, and the seat must suit the adapter’s bolt holes.
  3. Confirm full thread engagement in the hub.Each bolt must engage your hub by at least as much thread as your original wheel bolt did — never less — without bottoming out or fouling anything behind the hub. What is thread engagement? It’s how much of the bolt’s thread is actually screwed into the hub — this is what holds your wheel on. Simple check: when you take out an original bolt, count how many full turns it takes to come out once it’s loose. After fitting, each new bolt must take at least that many full turns to screw in by hand before its head reaches the adapter. Fewer turns means less thread holding the wheel on — do not drive the car. If a bolt stops turning before its head reaches the adapter, it may be too long or cross-threaded — don’t force it. Once every bolt is in, tighten them to your vehicle manufacturer’s specified torque setting using a torque wrench — check your owner’s handbook or a main dealer for the correct figure for your car.
  4. Check the bolt heads sit below the adapter face.The heads must sit fully inside their holes so the wheel can clamp flat against the adapter.

Joint 2 — wheel to adapter

  1. Match the thread to the adapter.The wheel bolts must match the thread size and pitch tapped into the adapter, which may differ from your car’s original bolts.
  2. Match the seat to your wheel.The seat type must match the wheels you are fitting, not the car. What is the seat? It’s the shape of the underside of the bolt head — the part that presses against your wheel. It’s usually either cone-shaped (called “conical” or “60° taper”) or rounded (called “ball” or “radius”). It must match the shape of the bolt holes in your wheel: the wrong shape only touches the wheel on a thin edge and can work loose. Simple check: hold a new bolt up to one of your wheel’s bolt holes — the underside of the head should sit snugly in the hole’s shape.
  3. Confirm full thread engagement in the adapter.Each bolt must engage the adapter’s threads fully, and any length that passes through must not touch the hub, brakes or the adapter-to-hub bolts behind it. In plain terms: the bolt should screw through the whole depth of the adapter’s threaded hole by hand, smoothly, until its head reaches the wheel. If it stops before the head reaches the wheel, it’s too long or cross-threaded; if it only catches a few turns, it’s too short — either way, don’t drive the car. Once every bolt is in, tighten them to your vehicle manufacturer’s specified torque setting using a torque wrench — check your owner’s handbook or a main dealer for the correct figure for your car.

If anything doesn’t match on either joint, don’t fit it — contact us with photos and measurements first. Fitting should be done by a competent person or a professional garage. Re-check all bolts after the first 50–100 miles. Brightstone Engineering cannot accept responsibility for problems caused by fitting bolts that have not been checked against the vehicle as described above.