The accumulated metal fatigue started as a small crack which grew until the axle was twisted in two. The [Brick Experiment Channel] is a fun one to check out, and we’ve featured them before.

[3] Fatigue crack non-propagation behavior of a gradient steel structure from induction hardened railway axles. International Journal of Fatigue (2023). [4] Safe life and damage tolerance aspects ...

Steel also has no fatigue limit in a corrosive environment, which is technically anything involving moisture and air over a long time span. Some mechanisms may work 30 years without a problem and ...

Look for cracks in axles, metal fatigue expert says. Reading Time: 3 minutes. Why you can trust SCMP. Stephen Chen in Beijing. Published: 12:00am, 23 Aug 2011.

"The original axles used 1020 Series steel with a 79-ksi ultimate strength. Results suggested using a 4340 bar stock, which has a 180-ksi ultimate-stress rating and better fatigue characteristics ...