Flange Thickness for Wheel Hubs: How to Choose Yours

Matching your situation to the correct Flange Thickness

How to measure and confirm your Flange Thickness

To find the correct flange thickness, you must measure the actual thickness of the mounting face on your existing wheel hub. This is the flat surface where the wheel bolts attach, not the total diameter of the hub or the thickness of the bearing seat.

Tools required for measurement

Use a digital caliper or a high-quality steel ruler to ensure accuracy to the nearest millimeter. Because wheel hubs are heavy and often oily, it is helpful to clean the mounting surface with a degreaser before taking a measurement.

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Where to find the measurement

Measure the flange thickness by placing the caliper across the mounting face. You are measuring the distance from the front of the flange to the back of the flange. If the hub is already installed, you may need to remove the wheel and the brake assembly to access the mounting face clearly.

Verifying with manufacturer data

If the hub is removed, you can often find the flange thickness listed in the vehicle’s technical specifications or the original equipment manufacturer (OEM) parts catalog. Look for the “flange thickness” or “hub depth” specification, which is typically listed in millimeters (mm).

Risks of incorrect Flange Thickness

Choosing a flange thickness that is too thin or too thick creates a physical mismatch between the hub, the brake assembly, and the wheel. These errors manifest as mechanical interference or safety hazards during operation.

Consequences of a flange that is too thin

If the flange is thinner than the original specification, the wheel will sit too far out from the axle. This change in offset can cause the tire to rub against the inner fender liner or the suspension components. It may also cause the brake caliper to sit too close to the wheel, potentially leading to rubbing or a complete inability to mount the wheel.

Consequences of a flange that is too thick

A flange that is thicker than the original specification pulls the wheel inward toward the axle. This reduces the clearance between the brake pads and the rotor, which can cause the brakes to drag or seize. In severe cases, the wheel may hit the brake caliper, preventing the vehicle from moving or causing immediate mechanical failure of the braking system.

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The result of a mismatch

Regardless of whether the flange is too thick or too thin, a mismatch will likely cause the wheel to be “out of true” relative to the braking system. This can lead to uneven tire wear, vibration at high speeds, and a significant reduction in braking reliability because the hub is not seated in its intended position.

What to do when you fall between two Flange Thickness values

If your measurements suggest a value that sits between two standard manufacturing options, you must determine which direction provides the necessary clearance for your specific brake setup. Because flange thickness directly affects the wheel’s protrusion, the choice depends on whether your current setup has more room toward the outside of the vehicle or toward the inside.

Prioritizing brake clearance

If your brake calipers are large and have limited clearance, you should prioritize a flange thickness that moves the wheel further away from the caliper. In most cases, this means selecting the larger mm measurement, provided there is enough physical space in the wheel well to accommodate the wider stance.

Prioritizing wheel well clearance

If your vehicle has a narrow wheel well or the tire is very close to the inner suspension, you must prioritize a flange thickness that keeps the wheel tucked in. In this scenario, you would choose the smaller mm measurement to ensure the tire does not contact the bodywork or suspension arms.

Consulting a professional

Because a mismatch in flange thickness can impact the vehicle’s safety and legal roadworthiness, you should confirm your final choice with a qualified mechanic. A professional can measure the available clearance in your specific wheel well and confirm which thickness allows for the safe operation of the braking system and the rotation of the wheels.

Reviewed by the Carworship editorial team. Carworship writes these guides from the 200 most-reviewed wheel hub listings in our retail dataset, not from manufacturer copy.