나사 가공시에는 공작물의 직경에 의한 회전수 변화가 생기면 나사의 피치가 일정하게 나오지 않습니다.Upon submission, you may receive a custom made QR code through e-mail which you can use at this participating showroom location to assert your advertising coupon!Thank you for declaring your coupon! You'll get a