April Photo Challenge - Comments & Notable Rejects

[Photo Challenge]

This is the thread for any comments that you would like to make about any of the submissions in this month's Photo Challenge.

Additionally, if you have any shots that you have taken on the subject, but didn't quite "make the cut", you can share them on this thread too.

This month's theme is "Metal"

NB:
Just to let you know, in the next two months I will be travelling in the outback, often with limited coverage. So bare with me and be patient if I am a bit late administering this challenge.

[Regulus]

Love 'old metal' that's well loved.

[astronobob]

Scrounged for 'practical' subjects out at horse paddocks, was bored with horse going round & round :P

[sheeny]

Corrosion on the gear on the end of the camshaft on a wrecked motor in Datchet Downs Station in outback Queensland.

The pinion gear at the bottom left of frame is on the crankshaft and this gear drove the cam shaft in this old pushrod engine. From the corrosion patterns on this gear resembling Damascus Steel, it is evident it was forged. Couldn't imaging forging that today. I would expect it to be machined from billet.

Al.