Needles were autoclaved and re-used once upon a time, so it should be possible. But disposable needles are probably made of softer material than reusable ones.
Those were made up harder steel which can’t be sharpened to the degree softer steel can be. Harder steel shatters if sharpened since harder it is brittle it becomes.
So reusable needle are blunt, so injections are painful. And as mentioned by @Natanox@discuss.tchncs.de they used to shatter inside the body after a few cycles of autoclaving.
Needles were autoclaved and re-used once upon a time, so it should be possible. But disposable needles are probably made of softer material than reusable ones.
Those were made up harder steel which can’t be sharpened to the degree softer steel can be. Harder steel shatters if sharpened since harder it is brittle it becomes.
So reusable needle are blunt, so injections are painful. And as mentioned by @Natanox@discuss.tchncs.de they used to shatter inside the body after a few cycles of autoclaving.