The forging process on our damascus billets starts out a mixture of 13 layers that include 5160, 203E, 15N20 and 52100 and then folded 5 times to produce a high contrast 416 layer damascus billet. All sizes are approximate. Ferric Chloride acid #BS110 is used to etch your blades. Made in the USA. Oversized in thickness up to .010".