Concrete screws are ideal for use in Concrete, Block, and Brick. They are mostly used in civil engineering.Concrete screws are a quick and convenient way to fasten to concrete. Concrete screws have a diamond point to make it easier to drive the screw to save time. The hex washer head concrete screws are designed to allow the head to sit on the top of the surface of the item being attached.PL: PLAIN YZ: YELLOW ZINC ZN: ZINC KP: BLACK PHOSPHATED BP: GREY PHOSPHATED BZ: BLACK ZINC BO: BLACK OXIDE DC: DACROTIZED RS: RUSPERT XY: XYLAN Head Styles Head Recess Threads Points We have our own fastener factories and have formed a professional production system from material supplying and manufacture to sale, as well as a professional R&D and QC team. We always keep ourselves updated with market trends. We are ready to introduce new technology and service to meet the market needs. OEM & ODM, customized design/logo/brand and package are acceptable. Advanced production equipment, strict quality testing and control system to make sure superior quality. Competitive price: we are a professional auto parts manufacturer in China, there is no middleman's profit, and you can get the most competitive price from us.