Many moons ago I had occasion to make some special stub axles out of EN24T. These axles, attached at one end only, had 8mm I.D. deep groove ball races on the inboard end and tiny 4mm I.D. races on the outboard end. As it turned out they were marginally not quite up to the job and deformed. I made another set out of EN24, hardened and tempered to the 100 ton condition which did the job.
The interesting thing is that when tested in the 100 ton condition the material, while capable of carrying much greater loads, was also capable of flexing considerably more than the EN24T examples without deformation but when grossly overloaded failed catastrophically.
The point of this little tale is that if you have a critical component make sure the material you use is up to the job.
Eventually we had the machine these were fitted to over 50mph without the driver having to change his underwear!!! We even let the press have a go but forebore to mention the size of the axles – well, you never know, we might have struck a blow for the common man!
