1.Our bolts is strong and durable. 2.China factory 3.Best price. 4.Good quality Standard: DIN Grade: 4 6 8 10Finished: plain,black,zinc plated and HDGDiameter:M2---M56We are specially in supply kinds of fastener with competitive price, high quality and on time delivery, Also we can produce according customer's drawings and sample.Welcome to contact us. Din 555 Nuts