Heavy Duty Relay or Switching Contacts 10 Pieces OM0357A


88 in stock

SKU: OM0357-1 Category:






For sale here we have the above…

10 Pieces

The power rating is not known but these are very heavy duty (possibly designed to handle up to to 20 Amps).  

They are new and unused but have been in storage for a long time a faded docket packed with them is dated 1974, unfortunately we can’t find any data on them.

Very robust heavy duty construction.


Diameter 7mm

Total Height including fixing plug 4mm

Approximate Weight of 10 pieces 7.2 Gram

Total weight of the contacts we have in stock at time of listing was 1 Kilogram

As to the material used in their construction we have no information available but as they came from a ‘Milspec’ type manufacturer we suspect high end materials were used. Silver, gold and the platinum group metals are often used as electrical contacts because of their high electrical conductivity we don’t think gold was used as they are obviously silver in colour. To overcome the issues faced by using pure precious metals, they are often alloyed with other metals, including other precious and non-precious metals. The principle contact materials used for relays with nominal contact ratings within the range 5 to 50 A are most commonly, Silver Nickel, Silver Cadmium Oxide and Silver Tin Oxide. Platinum and Palladium are two more exotic materials sometimes alloyed or combined/produced by using the powder/sintering process.
Silver Nickel has been around for “almost ever”. The relatively small nickel content (10%) is primarily to mechanically harden the silver and increase the resistance to electrical erosion of the contact faces, therefore making it that much more robust under heavier electrical load. It is ideal for resistive loads at the full nominal current rating of the contact, and for other loads where the load current is not so high. It is an economical and good performing general-purpose material and quite often the standard material for many power relays.


These parts came to us as part of a lot of surplus stock from a large Milspec type Co. and have been kept in storage for some time, we have therefore classified them as ‘new other’. They are however in good condition, stored with us still in the original packaging they came in, the photographs are representative of their general condition being of some of our actual stock, and, as with all our products they come with a full guarantee as to serviceability

If you have similar items to this, or indeed any electronic components that are surplus to requirements please contact us with details.



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