wide head drywall screws

Uses: water conservancy engineering, river regulation engineering, dike engineering, ecological protection engineering, channel lining, road engineering, river bank reinforcement, ocean engineering, landscape design engineering, bridge reinforcement, railway and highway slope protection, retaining wall, ecological river bank slope regulation and other engineering.

6, passivation to remove hydrogen parts should be passivation after the removal of hydrogen, passivation before the application of 1%H2SO4 or 1% hydrochloric acid activation 5~15s. Passivation shall be treated with colored chromate unless otherwise specified in the design drawings.