Square Bolt Supplier in Ahmedabad

About Square Head Bolts

A square bolt has a four-sided head. The square head is easy to grip with a spanner and does not turn in square holes or slots. There are two main types, and they are not interchangeable:

• Small square head to DIN 478 (with collar), DIN 479 (with short dog point) or DIN 480 (with collar and rounded short dog point). The head is about as wide as the thread diameter, so it suits machines and machine tools where space is tight. These DIN standards cover sizes up to M24.
• Large square head, such as the square bolts in ASME B18.2.1 (inch sizes). The head is about 1.5 times the bolt diameter across flats. This gives a large bearing face for timber and heavy construction work.

Please give the standard, or send a drawing or sample, with your enquiry. Other sizes are quoted against your drawing.

Applications

• Machine tables and T-slots
• Timber structures and construction
• Railway and track fittings
• Agricultural equipment and heavy machinery

Square Bolt FAQs

Why use a square head instead of a hex head?

A square head gives a firm grip for spanners and stays fixed in square slots. A large square head also has a bigger bearing face than a hex head of the same width across flats. For general work, hex heads are the more common choice.

Which grade of square bolt should I choose?

Mild steel 4.6 or 5.6 suits general fixing and timber work. High tensile 8.8 or 10.9 is used for heavy machinery and loaded joints. Choose SS 304 or SS 316 where rust is a concern, and SS 202 for dry, indoor use. Our bolt grade chart explains the grades.

Which nut goes with a square bolt?

A hex nut or a square nut of the same thread and a matching grade. On timber, add a square washer under the nut to spread the load.