The Nut is a component of a fastening arrangement with a female thread (on the inside). It normally has some shape or form on the outside to assist with rotating it so that it will tighten onto a male part and typically come in a right handed thread (tightened when turned in a clockwise direction). Note that some nuts are available that are left hand threaded (tightened when turned anti-clockwise).

• Hexagon Nuts - Hex Nuts are the most commonly used nut for all types of fastenings. They are available in metric coarse thread (standard), metric fine threads, Unified National Coarse (UNC), Unified National Fine (UNF) and British Standard Whitworth (BSW). Metric sizes are made to the DIN 934 standard.
• Nyloc Nuts - Similar and complimentary to the hexagon range, the major difference being the nylon ring inserted at the end of the nut. This is a self-locking device to stop the nut undoing under constant vibration or load variations. It is not suitable for use where the temperature is liable to exceed 120 degrees Celsius. For uses where high temperatures are incurred a range of spring metal lock nuts are available in 304 grade only. Metric sizes are made to the DIN 985 standard.
• Dome Nuts - (Acorn or Cap Nuts) come in two styles, one piece or two piece. A one piece Dome Nut is made from a solid piece of stainless to DIN 1587 Standards and the two piece is a hexagon nut with a dome cap fused to one end and made with a high polish finish.
• Lock Nuts, Half Nuts or Jam Nuts - These are used under a Hex Nut or another Lock Nut to lock the fastening and stop it from undoing. They are similar to a Hex Nut but not as high and in metric sizes are made to the DIN 439 standard.
• Wing Nuts - The range and grades are similar to the hexagon nuts. These nuts are used in situations where a fastening is often undone and done up but does not require an over tight fitting. The pressure that can be exerted by your fingers is sufficient to hold the fastening.
• Hank Bushes - These are internally threaded but with a round outside and with a small reduced diameter shoulder. Designed for welding into sheet metal fabrications so that a fastening can be used to hold firmly in the sheet product.
• Coupling Nuts - These are very long hexagon nuts that are used to join two long threads together and are made to DIN 6334 standard.
• Flange Nuts - Used mainly on concrete retaining type fastenings and automotive or sheetmetal fabrications. They are made for sheetmetal punching and are designed so that the 4 prongs and body come through from the back of timber and hold to stop the nut from rotating. They are mainly used in furniture/upholstery work.
• Barrel Nuts - Barrel Nuts have a long internal female thread and one end closed with a drive. Either Philips, Slot or Socket.
• Bumax Nuts - Bumax Nuts are a range of higher tensile Stainless Steel hexagon nuts.

For Australian customers see Stainless Steel Nuts