The product's brand as the YZ, standard type for mn - 4 WD, models for Q623, nominal length is 8 ~ 20 mm, the thread tolerance is 6 g, surface treatment is galvanized, material is carbon steel 45 h, product specifications for the m12 - m42, thread specifications for m12 - m42, Allen process for cold heading.Metric system is complete, high quality products, affordable, the door-to-door delivery.