19-10-2021, 07:44 PM
(This post was last modified: 19-10-2021, 07:57 PM by Bob Culver.)
Thanks Colin
Failure from internal inclusions is rare esp with clean modern steels. The example is likely a lab straight tension situation. Except in very ht steels the final failure metal is usually quite evident.
In the original second photo the rotation has caused the crack to extend full circle much as for an inclusion in straight tension, although progressing inward instead of outward.
I dont know if the key postion differs in detail between the early thin .875 axles and the 1930s thicker .890 ones but I have encountered after market later shafts thin at the outer end. The taper contact then ends very close to the keyway with inevitable early cracks
The first posted photo seems to have a turning groove around it. perhaps it was a reclaimed shaft.
I have observed Hillman Hunter axles. These have been heavily surface rolled all over to place the surface in protective compression
There is a stress limit below which steel lasts forever. But there is probably no part of the car, bodywork included, where the level is not exceeded occasionally, even if only in exceptional circumsatnces. So if you drove to infinity everything would fail eventually.
I like the photos of workshops. Which is oldedest? The vice or lino/carpet?
Failure from internal inclusions is rare esp with clean modern steels. The example is likely a lab straight tension situation. Except in very ht steels the final failure metal is usually quite evident.
In the original second photo the rotation has caused the crack to extend full circle much as for an inclusion in straight tension, although progressing inward instead of outward.
I dont know if the key postion differs in detail between the early thin .875 axles and the 1930s thicker .890 ones but I have encountered after market later shafts thin at the outer end. The taper contact then ends very close to the keyway with inevitable early cracks
The first posted photo seems to have a turning groove around it. perhaps it was a reclaimed shaft.
I have observed Hillman Hunter axles. These have been heavily surface rolled all over to place the surface in protective compression
There is a stress limit below which steel lasts forever. But there is probably no part of the car, bodywork included, where the level is not exceeded occasionally, even if only in exceptional circumsatnces. So if you drove to infinity everything would fail eventually.
I like the photos of workshops. Which is oldedest? The vice or lino/carpet?