A square nut is a four-sided

nut Nut often refers to: * Nut (fruit), fruit composed of a hard shell and a seed, or a collective noun for dry and edible fruits or seeds * Nut (hardware), fastener used with a bolt Nut or Nuts may also refer to: Arts, entertainment, and media Com ...

. Compared to standard hex nuts, square nuts have a greater surface in contact with the part being fastened, and therefore provide greater resistance to loosening (though also greater resistance to tightening). They are also much less likely to become rounded-off after repeated loosening/tightening cycles. Square nuts are typically mated with square-headed bolts. Square nuts are used along with flat washers to avoid damage from its sharp edges and increase the strength of the fastener. Square nuts can have standard, fine or coarse threading with platings of

zinc yellow Chromate conversion coating or alodine coating is a type of conversion coating used to passivate steel, aluminium, zinc, cadmium, copper, silver, titanium, magnesium, and tin alloys. The coating serves as a corrosion inhibitor, as a prim ...

, plain, zinc clear,

tin Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is a silvery-coloured metal. Tin is soft enough to be cut with little force and a bar of tin can be bent by hand with little effort. When bent, ...

and

cadmium Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, silvery-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it demonstrates oxidation state +2 in most of ...

, among others. Most can meet either the ASTM A194, ASTM A563, or ASTM F594 standard.

Benefits

Tighten easily by gripping two sides Work well in tight spaces by using needle nosed pliers Work well in blind spots using

pliers Pliers are a hand tool used to hold objects firmly, possibly developed from tongs used to handle hot metal in Bronze Age Europe. They are also useful for bending and physically compressing a wide range of materials. Generally, pliers consi ...

or a

wrench A wrench or spanner is a tool used to provide grip and mechanical advantage in applying torque to turn objects—usually rotary fasteners, such as nuts and bolts—or keep them from turning. In the UK, Ireland, Australia, and New Zeala ...

Can be a quick gauge to measure the position of the nut

Application

Commonly used in furniture as a blind nut, they are also used in rail channels to prevent turning of rail when pressure is applied. They are also used as a perfect foundation in metal channels for hidden

fastener A fastener (US English) or fastening (UK English) is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints; that is, joints that can be removed or disman ...

References

{{Nuts (hardware) Nuts (hardware)