We are a Japanese antique dealer company. Japan antique dealer number: 921060000398. Diameter of the frame press-fitting part: Approx. High strength hardened shaft & nut. The best 3-piece crank & American BB set for Old BMX. It does not contain the KUWAHARA engraving or logo. There are some small scratches and rubbing during manufacturing. Please understand in advance before purchasing. Thank you for your understanding.