Originally Posted by LóFarkas
Wow, the cog proudly says "CNC'D". Do they think that riders don't know that forging would result in a stronger cog, but it would be a bit more complicated to do? It's not such a complex shape as to require CNC, is it???
phil cogs are cnc machined, then triple heat treated. eai cogs are machined as well. i would imagine that the precision that cnc offers helps prevent uneven wear and stress on the cog.
i would also assume that 13T-17T cogs are machined from one size blank, and 18T-22T are made from another. cold forging is really efficient when you're making a lot of the same thing, however it would require a ton of machinery to make 10 different sizes of cogs in 2 different pitches.
stainless steel is arguably a better material than cromoly for cogs because it is more resistant to corrosion,. However it is brittle and normalizing it with heat acts to prevent the cog from cracking under stress.