Upgrading your car’s wheels is one of the most exciting modifications you can make. But sometimes, the perfect wheels you’ve been eyeing don’t come in the bolt pattern your vehicle needs. That’s where custom-drilled wheels come in. As someone who has worked in the automotive industry for years, I’ve seen firsthand how CNC machining can transform a generic wheel into a precision-fit performance upgrade.
Whether you’re aiming for a cleaner look, improved handling, or the ability to mount a unique wheel design, custom drilled wheels open up possibilities you never thought possible.
In this guide, I’ll walk you step-by-step through the process, from understanding PCD (Pitch Circle Diameter) and hub bores to ensuring your wheels are balanced and safe to drive. I’ll also share a personal story about a project where I transformed plain wheel blanks into head-turning showpieces.
Table of Contents
Key Takeaways
- Custom drilled wheels are standard or blank wheels that are drilled to match your vehicle’s exact bolt pattern.
- They allow you to use wheel designs that wouldn’t otherwise fit your car.
- This guide covers measuring, choosing wheel types, CNC drilling, finishing, test fitting, and maintenance.
- The process requires precise tools like a drill jig and should follow proper stress analysis to maintain wheel strength.
- Choosing between cast wheels, flow-formed wheels, and forged alloy wheels can affect weight, durability, and cost.
What Are Custom Drilled Wheels?
Custom drilled wheels are aftermarket or blank wheels that have their lug holes professionally machined to match the exact bolt pattern of your car. Instead of being locked into factory specs, you can choose from a huge variety of wheel designs.
The process typically involves using CNC machining to ensure the holes are placed with extreme accuracy. This prevents vibration, ensures even load distribution, and avoids damage to the wheel hub. Some wheels are dual-drilled, meaning they have two sets of bolt holes to fit multiple PCDs, a great choice if you plan to swap wheels between vehicles.
Done correctly, this modification doesn’t compromise safety. Stress analysis is often used to ensure the wheel maintains its original strength rating.
Benefits of Choosing Custom Drilled Wheels
Investing in custom-drilled wheels offers multiple advantages:
- Perfect Fitment – Matched to your bolt pattern and hub bore, so no wobble or unsafe gaps.
- Design Freedom – Access to wheel styles that aren’t made for your vehicle’s fitment.
- Performance Gains – The right wheel weight and offset can improve acceleration and handling.
- Resale Flexibility – With dual-drilled wheels, you can sell them to owners of cars with a different PCD.
- Cost Savings – Sometimes cheaper than buying a brand-new set in your bolt pattern.
I once had a customer with a rare Japanese import who couldn’t find wheels in the correct PCD. By custom drilling a set of lightweight forged alloys, we achieved a factory-like fit with a style that wasn’t available off the shelf.
Understanding Bolt Pattern (PCD) & Why It Matters for Custom Drilled Wheels
The bolt pattern, also known as PCD, is the diameter of the circle that passes through the centre of all your lug holes. For example, “5×114.3” means 5 lug holes arranged in a 114.3 mm diameter circle.
You can read a clear breakdown of how to measure bolt pattern (PCD) to make sure your measurements are accurate before custom drilling.
If the PCD doesn’t match, the wheel won’t seat properly on the hub, leading to wheel fitment issues, vibrations, and even dangerous wheel failure. That’s why custom-drilled wheels are carefully measured before drilling to ensure a perfect match.
You also need to consider hub bore size, the centre hole of the wheel that fits over your car’s hub. A correct hub bore ensures the wheel is hub-centric, preventing unnecessary strain on lug nuts.
Measuring Your Car’s Bolt Pattern: Step 1 of the Guide
Before drilling, you need accurate measurements. Here’s how:
- Count the Lug Holes – Most cars have 4, 5, or 6.
- Measure the PCD – For even lugs, measure center-to-center. For odd lugs (like 5), measure from the back of one lug hole to the centre of the opposite lug hole.
- Check Hub Bore Size – Use a caliper for accuracy.
- Note Wheel Offset & Backspacing – These affect fitment and clearance.
For example, my old BMW E36 had a PCD of 5×120, but I fell in love with a set of JDM wheels in 5×114.3. Measuring precisely was the first step in making them work with custom drilling.
Choosing the Right Wheel Type: Cast, Flow Formed, or Forged
When planning custom drilled wheels, you must choose the right wheel material:
- Cast wheels – Affordable, made by pouring molten aluminium into moulds. Heavier but fine for daily driving.
- Flow-formed wheels – Stronger and lighter than cast, made by spinning and stretching the metal.
- Forged alloy wheels – Premium, extremely strong, and light. Best for performance and racing.
Drilling forged wheels is more labour-intensive due to their hardness, but the result is unmatched in strength.
Tools & Equipment Needed for Custom Drilled Wheels
Professional shops use specialised gear for custom-drilled wheels:
- CNC machining centres – For precision drilling.
- Drill jigs – To guide drill bits perfectly.
- Deburring tools – To smooth hole edges.
- Measuring callipers – For exact hub bore and PCD.
- Hub-centric ring gauges – To ensure perfect fitment.
If you’re DIY-minded, remember that a standard drill press won’t achieve the accuracy needed for safe results.
CNC Drilling Process Explained: Step 2 of the Guide
The CNC drilling process for custom-drilled wheels follows these steps:
- Secure the wheel in the CNC fixture.
- Input PCD, bolt count, and hub bore into the system.
- Machine-precise holes at the programmed coordinates.
- Deburr to remove sharp edges.
- Inspect for accuracy using a dial gauge.
This method ensures zero deviation, which is vital for wheel balance and structural integrity.
Deburring, Counter-bore & Hub Bore Finishing
After drilling, holes must be deburred, and sharp edges must be removed to prevent cracks. In some cases, counter-boring is done to allow the lug nut or bolt to seat properly.
If the hub bore is too small, it may also be machined to match your vehicle. This step ensures the wheel sits perfectly centred on the hub, avoiding NVH issues.
How to Test Fit Your Custom Drilled Wheels: Step 3
Before final installation:
- Mount the wheel without tires to check fit.
- Spin the wheel to ensure it doesn’t rub brake callipers or suspension.
- Check backspacing and clearance.
- Use hub-centric rings if needed.
A test fit saved me once—my wheel cleared the brakes by just 2 mm. Without checking, I could have damaged both the wheel and the callipers.
Torque, Alignment & Balancing Checks for Safety
Even perfectly drilled wheels need correct installation:
- Torque lug nuts to manufacturer specs.
- Get a wheel alignment to ensure handling stability.
- Balance wheels to avoid vibrations at speed.
Neglecting these steps can undo all the precision work of custom drilling.
Maintenance Tips for Long-Term Care of Custom Drilled Wheels
To keep your custom drilled wheels in top shape:
- Wash regularly to remove brake dust.
- Re-torque lug nuts after 50–100 miles.
- Inspect for cracks or damage.
- Avoid harsh impacts; potholes can bend rims.
Real-World Anecdote: My Journey with Custom Drilled Wheels
A few years ago, I bought a rare set of flow-formed wheels from Japan. They were gorgeous, but had the wrong PCD. A trusted machinist drilled them precisely for my car’s specs. The first drive after installation felt like magic, smooth steering, no vibration, and compliments at every gas stop. That’s the power of a properly done custom-drilled wheel job.
Pros, Cons & Cost Breakdown of Custom Drilled Wheels
Pros: Perfect fitment, style flexibility, potential cost savings.
Cons: Needs expert machining, can void wheel warranty, and not all wheels can be drilled.
Costs vary, $50–$100 per wheel for drilling, plus potential extra for hub boring.
Conclusion
Custom drilled wheels are the ultimate solution when you want style and performance without compromise. With the right measurements, tools, and expertise, you can make almost any wheel fit your vehicle perfectly.
FAQs
Are custom-drilled wheels safe?
Yes, when done by professionals with proper stress testing.
Can I drill wheels at home?
Not recommended—precision CNC machines are needed.
Will custom drilling weaken my wheels?
If done correctly, the structural integrity remains intact.
What is a dual-drilled wheel?
A wheel with two sets of bolt holes for different PCDs.
Do I need hub-centric rings?
Only if your hub bore is smaller than the wheel’s centre hole.
How long does drilling take?
Usually 1–2 days, depending on workload.
Can steel wheels be custom drilled?
Yes, though alloy is more common.
Is re-drilling reversible?
No—once drilled, holes can’t be undone.
What’s the lifespan of custom-drilled wheels?
Equal to standard wheels if maintained well.
Do custom-drilled wheels affect resale value?
Sometimes, they can appeal to enthusiasts with the same bolt pattern.
