I know that cold forging allows for sleeker designs because cold forged aluminium is stronger. Are there any other giveaways that indicate a certain manufacturing process?
quoting Chris Bell:
Unfortunately all aluminium cranks look similar to the untrained eye so it is worth taking advice when buying a pair. Don't be fooled by the deliberate misuse of the term 'forged' as I've even seen that label written on the backs of poor-quality cast cranks. Fortunately, however, many cast cranks are perfectly strong enough for normal use.