Clicking the stamper takes 10 seconds to convert 1 Sheet Metal into 20 blades.
So that's roughly 1 minute to make a full stack of 100 Alaran Throwing Blades.
They are not Temporary, but they are Magic and ALL / ALL !
The Stamper is crafted by a Tinker, the blades are made (converted) by the device, not exactly summoned or crafted.
Stamper has 20 charges when fully charged, Sheet Metal is sold 20 to a stack,
you can make 4 stacks of 100 blades then it's time to buy a battery (#6) to recharge it.