Hexagon domed cap nut (also called acorn nut) features a closed, rounded dome that fully covers the bolt end. The cap protects exposed threads from physical damage and corrosion while providing a dust- and splash-resistant closure and a finished appearance.

Materials offered include carbon steel and stainless steel grades A2 (304) and A4 (316). Surface treatments listed are zinc plating, black oxide and bright polishing. Manufactured to GB/T 923, DIN 1587 and ISO 4033 dimensions — confirm the required standard, thread form and size when ordering. Common applications include railings, furniture, machinery, doors and windows, and vehicle parts.