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SAE J267: Fatigue Testing and Performance Requirements for Truck and Bus Wheels
🛠️ SAE J267 (Revised 2021) defines minimum performance targets and uniform laboratory procedures for fatigue testing of wheels and demountable rims used on trucks, buses, truck-trailers, and multipurpose vehicles. The standard covers dynamic cornering fatigue tests (disc wheels) and radial fatigue tests, providing a statistical framework using Weibull analysis to ensure design confidence and field reliability.
Scope and Application
This SAE Recommended Practice applies to wheels intended for normal highway use on commercial vehicles. It does not cover passenger car or light truck wheels (refer to SAE J328), trailer wheels (SAE J1204), or special application rims. The document is a key reference for wheel manufacturers, test engineers, and vehicle integrators who need a consistent, repeatable method to validate wheel endurance under simulated service loads.
Key Reference: SAE J267 is part of a family of wheel test standards. For aftermarket light-truck wheels, refer to SAE J2530; for military bolt-together wheels, see SAE J1992.
Dynamic Cornering and Radial Fatigue Tests
Cornering Fatigue Test (Disc Wheels)
The cornering fatigue test applies a rotating bending moment to simulate the loads experienced during turning. The bending moment M is calculated using the test load factor S, static loaded radius, wheel inset/outset, and load rating:
M = L × (μ × slr + d) × S
Where μ = 0.7 (coefficient of friction), slr = static loaded radius, d = inset/outset, and S = accelerated test factor from Table 1. The test load is applied parallel to the rim center plane, and the machine must maintain load within ±3%.
| Test Factor (S) | 7 Samples (target cycles) | 6 Samples | 5 Samples | 4 Samples | 3 Samples | 2 Samples |
|---|---|---|---|---|---|---|
| 1.45 | 30,000 | 33,000 | 36,000 | 40,000 | 46,000 | 57,000 |
| 1.60 | 18,000 | 20,000 | 22,000 | 24,000 | 28,000 | 34,000 |
Test termination criteria differ for ferrous (crack through section) and aluminum (crack >10 mm on exterior profile outside disc flat clearance diameter +15 mm). Broken studs do not automatically invalidate the test but may cause damage.
Radial Fatigue Test (Disc Wheels and Demountable Rims)
The radial fatigue test simulates the vertical loads from road irregularities. The test machine applies a radial load through a tire or drum, and the wheel must survive a specified number of cycles without failure. The standard provides similar sample-size-dependent cycle tables for radial testing (Section 5, Table 2 – not reproduced fully here).
Engineering Insights and Statistical Confidence
⚠️ The cycle targets in J267 are based on Weibull statistics with two-parameter median ranks at 50% confidence and 90% reliability (B10C50). This means that at the target cycle, only 10% of the population is expected to fail, with 50% confidence. The standard allows multiple sample sizes (from 2 to 7) each providing equivalent confidence and reliability, offering flexibility in testing budget and schedule.
Common Mistake: Using non-representative wheels – test wheels must be fully processed, new, and representative of production. Also, incorrect lug nut torque or dirty mating surfaces can skew results. Always follow Appendix A torque specifications and verify shaft runout ≤0.25 mm.
The accelerated test factors (ranging from 1.10 to 1.63) magnify service loads to achieve failures in a reasonable test duration. For ferrous wheels with large inset (≥4 in), a lower factor (1.10) is used due to higher baseline offset loads. Aluminum wheels require higher cycles (e.g., 250,000 cycles for 7 samples at factor 1.35) reflecting their different fatigue behavior.
Frequently Asked Questions
How is the bending moment determined for the cornering fatigue test?
The bending moment M = L × (μ·slr + d) × S, where L is the wheel load rating, μ = 0.7, slr is the largest static loaded radius, d is the inset (positive) or outset (negative), and S is the test factor from Table 1.
What does “B10C50” mean?
B10 means 10% of the population is predicted to fail at the target cycles. C50 indicates 50% confidence. The combination gives statistical reliability that the design meets the minimum performance target.
Can I test with fewer than seven samples?
Yes. Tables 1 and 2 provide equivalent cycle targets for 2–7 samples, all offering the same confidence and reliability. Fewer samples require more cycles per sample.
What are the most common errors in wheel fatigue testing?
Using worn wheels, improper lug nut torque, failing to clean mating surfaces, not aligning the load parallel to the rim plane, and neglecting shaft runout checks (must be ≤0.25 mm TIR).
🔍 For more details, refer to the full SAE J267 document. Understanding these test procedures and statistical foundations helps engineers design safer, more durable wheels for commercial vehicles.
