Do you mean the symbol near the number or the one that looks like an inverted screwdriver slot? The symbol near the number is most likely a manufacturers mark, but I do not recognise it. The screw head symbol is like a batch or date code marker. If you look carefully there are some numbers there. A clean up would reveal them. This is fairly common practice in castings. A removable part is placed in the tool that has the batch/date markings. This is changed at each batch run. Peter.
Just a random search on google to show an example http://the.shadock.free.fr/sherman_minutia/casting_markings/casting_markings.html
Same as the Casting mark on those FZR600 forks I am getting... I wonder if it is a Yamaha Casting mark??
FWIW I have seen similar casting marks on plastics, perhaps metals, however they're usually accompanied by alpha numericals around the circumference to give M/Y dates of production
Depends on the quality and the amount of post forging/casting machining that was done. A sandy texture, and obvious mold parting line is a dead giveaway that it’s cast. But, if all surfaces have been machined after casting, you would have to cut a slice out of the part, polish it, etch it with acid, and examine it under a microscope to tell if it was forged or cast. For anyone wondering...Casting is the process where metal is heated until molten. While in the molten or liquid state it is poured into a mold or vessel to create a desired shape. Forging is the application of thermal and mechanical energy to steel billets or ingots to cause the material to change shape while in a solid state.
