Yamada woks are known for a top quality highly evaluated by professionals for its elaborately hammered surface, which is made one by one and totally distinctive from that of pressed woks. The woks are machine hammered over 5,000 times to ensure perfect interaction with cooking oil, and engineered to have different thickness depending on the parts to ensure that heat is transmitted uniformly. Because these woks are all handmade, each wok is slightly different in size. Fine scratches, minor imperfections on the surface, or minor variations in color may be found, but these are all proofs that these woks are individually handmade. The varnish needs to be burnt off over high heat to expose the bare metal underneath, and the wok needs to be thoroughly seasoned before first use. For the way how to season the wok, please kindly refer to the following page: Have an all-around Japanese wok in your kitchen! Background Yamada Kogyosho, Y.K. was founded in Yokohama, Kanagawa, Japan in 1957. Yamada is a family-owned craft factory run over three generations and they are the only manufacturer of hammered woks in Japan.