The stamp is made of high quality High-speed steel (hrc55-60) . Its made for strength and hardiness to insure the stamp is ready when you need it. The head of the stamp is made of the same quality steel and should give you the cat paw stamp every time. Pattern Width 8mm/0.315" or 9mm/0.354" This stamp is recommended for use on annealed silver, gold, or copper sheets. If the metal sheets have not been annealed, the stamping results may not be as good. Great stamping set for festival, birthday, anniversary or christmas handmade gift