usually camshafts are made to be exposed to a lot of beating
but a simple crack may lead to total failure.
sa crack nagsisimula ang fatigue failure.
kung wala, then good.
pero kung meron minute crack, better replace or else overhaul kapag nabreak yan. yung sabi-sabi kasi ng machine shop na "pwede pa yan" is sometimes doubtful lalu na kung kinuha lang sa tingin ang checking or minadali and pagcheck
usually by order ang camshafts sa auto supply or you may check sa surplusan.
the material is either cast iron (if old school engine yan) but probably not aluminum. cast iron does not bend. it breaks suddenly without warning if stress is exceeded
or either the high speed steel as mentioned by dusky lim which is medium carbon steel with nickel-chromium-molybdenum alloying elements for wear, abrasion, corrosion- resistance and hardness