Square head bolt features square-shaped head. When installed into square recess of workpiece, the bolt stays fixed without rotation during nut tightening, no extra tool needed to hold the head.
Materials: Grade 4.8 / 8.8 carbon steel; A2(304)/A4(316) stainless steel optional.
Surface finish: black oxide, blue-white zinc, yellow zinc, hot-dip galvanized.
Widely used for steel brackets, guardrails, agricultural machinery, solar supports, tunnel support and construction machinery.