Square Nut

Four-sided internally threaded fastener manufactured to DIN 557, providing greater bearing surface area and rotation resistance compared to hex nuts. Used in slot, channel, and timber connections where anti-rotation is critical.

Specification #

Dimension #

• All dimensions in mm, tolerance +/- 0.01 mm. Additional dimensions available on request.

Benefits #

Square nuts address two specific engineering challenges that hex nuts cannot solve effectively. First, the four-sided geometry provides inherent rotation resistance when installed in square holes, channels, and T-slots, eliminating the need to hold the nut with a second wrench during bolt tightening. This is critical in timber construction with coach bolts, where the nut must remain stationary as the bolt is driven from the opposite side. Second, the wider bearing surface distributes clamping force over a larger area, reducing surface pressure on soft materials like wood and preventing pull-through failures. The flat bearing faces also provide more consistent contact with uneven or rough surfaces compared to the chamfered edges of hex nuts. In machine tool T-slot tables and channel mounting systems, square nuts self-locate within the slot, simplifying fixture setup and reducing assembly time.

Common Applications #

Square nuts are selected for applications where rotation resistance and wide load distribution are primary requirements.

• Timber and wood construction connections with coach bolts
• Channel and slot mounting systems
• T-slot machine table fixtures
• Furniture assembly (bolt-through connections)
• Electrical switchgear and panel mounting
• Concrete formwork and shuttering
• Pipe hanger and support systems
• Structural timber connections