A question we are often asked is ‘what exactly are washers for?’. The simple yet essential device, which can be purchased from BS Fixings (once you know what they’re for!) has been part of our daily lives for a long time, so let’s go right back to the start.
One succinct dictionary definition of a washer is "a perforated annular disc or flattened ring of metal, leather, or other material placed between two surfaces subject to rotative friction, to relieve friction and prevent lateral motion and unsteadiness". The word, which is curiously difficult to trace the origin of, has been around since at least 1346 (when it was spelled whashers) and was at that time defined as “an iron hoope, amongst gunners called a washer, which serues to keepe the iron pin at the end of the axeltree from wearing the naue”. Whatever that means.
Penny washers, also known as flat washers, are the most common kind that you're likely to come across and generally serve three distinct purposes:
The distribution of nut/bolt pressure evenly over the part to be secured, reducing the chance of that part being damaged
The provision of a smooth, level surface for the nut/bolt to bear upon, reducing the likelihood of loosening due to uneven fastening surfaces
The creation of an effective seal against water ingress (these are then known as plumbing washers)
Two other purposes that washers are used for, though this is not a proper usage and can be dangerous to health and/or damaging to property, are:
To permit bolts/nuts of insufficient size to be used in the holes of a secured part
To facilitate the tightening of a nut/bolt that is too long for the job
Nuts and bolts function by placing tension on a threaded shaft, strengthening the joint and reducing fatigue of the component; this is particularly important for variable loads such as machine parts that experience vibration. If any part deforms under these loads (e.g. thread contact area has ‘plastic flow’ or ‘creep’, raised points on contact surface between threads become flattened or fastened parts become compressed/lengthened) the joint loses tension and no longer functions optimally. By providing a bridge between the gap, washers preclude this possibility.
BS Fixings supply a select range of stainless steel washers manufactured from Grade 304 (A2) metal. Supplied in handy, cost-effective boxes of 100, the washers are guaranteed to exceed quality specifications and offer superior resistance to corrosion. Check out our range of stainless steel washers and call us for more information if you need any further support.