Washers

What's the function of washers for bolts fixings?

Washers prevent damage to the underlying structure during the tightening of the screw or bolt connection. In addition, a washer spreads the compressive force of the screw or bolt connection over a larger surface area. Certain washers, such as spring washers and lock washers, actually prevent the screw connection from loosening. And then there are washers that seal a connection watertight. In short, washers come in many shapes and sizes and can fulfil multiple functions at the same time.

What types of washers are available?

Plastic and metal washers are available in various designs. Here is a brief explanation for each type:

• Washers and penny washers
  By far the most commonly used washers. We supply washers that meet DIN/ISO standards like: DIN 125 / ISO 7089, DIN 126 / ISO 7091, DIN 433 / ISO 7092, DIN 9021 / ISO 7093
• Lock washers
  Lock washer secure bolted joints and thus preventing unwanted loosening of bolt or nut. A well-known example are spring washers according to DIN 127 / ISO 7090. Metal locking washers are often knurled, corrugated or notched. Plastic locking washers are generally fitted with squash edges.
• Retaining rings for shafts and pins
  Also called shaft retaining or fixing rings, are clamped around a shaft or pin to hold it in a certain position. There are shaft retaining rings that are inserted into a groove, as well as versions that are clamped onto the shaft.
• Anti-loss washers
  Anti-loss washers prevent bolts or screws from falling out of an object by holding onto the threads. Ideal for hard-to-reach places etc.
• Sealing washers
  Although most washers have some degree of sealing effect, there are special plastic washers that make a joint fluid and gas tight. Often based on crush edges that deform during tightening of the screw connection.
• Insulation washers
  Insulation washers are used as electrical insulators or to prevent electrolytic or galvanic corrosion. The washer and sleeve, also referred to as shoulder washers, prevent the bolt from coming into contact with the underlying or surrounding material.
• Finishing washers
  Finishing washers offer a neat finish to surface-mounted screw heads with flat or countersunk heads. The screw head drops into the finishing washer. Ideal for situations where underlying sheet metal parts are subject to expansion and contraction.

As standard, the above mentioned washers are suitable for metric thread sizes. Popular are washers sizes are M6, M8, M10, M12, M16, M22, M24 and M36. Naturally, many other thread sizes are also available.

In what material are washers available?

Most washers are available in plastics such as polyamide (Nylon), polypropylene, PTFE (Teflon) or POM. On request, other plastics like PEEK and even rubbers like EPDM or CR (Neoprene) are also possible. Our range also includes galvanised steel or stainless steel washers.