When does mil-spec matter?

Connector specialist, ECCO, offers advice on determining whether to specify military standard parts or commercial equivalents

Authorized distributor,ECCO, is often asked when is it appropriate to specify MIL-STD or mil-spec products over commercial counterparts? There are various factors to consider in situations where both types are an option, as well as assessing the worst case situations that can occur.

Military standard connectors are those approved for use by the US Department of Defense, following rigorous standards regarding factors such as interoperability and reliability. Nowadays, MIL-STD, or MS connectors, are also used in aerospace, industrial, marine and even commercial automotive applications.

Commercial counterparts are often made of the same materials, sometimes they even come off the same production line at the same factory. If this is the case, pricing should be similar, however, supply and demand may dictate variances in the pricing of either part. Where supply is limited, for example, the market price for a commercial part could be higher than its MS cousin. Often, however, commercial equivalent connectors are justifiably cheaper, due to material changes, such as contacts with less gold content. Lower material costs mean a lower price for the end customer and if the commercial part is produced at a separate factory with lower labor costs, this could also result in a lower final price.

Bearing this in mind, there may be good reasons for specifying a commercial part, particularly where cost is an issue and there is no MS requirement from the end customer. But, when it comes to deciding on MS versus commercial equivalents, what criteria should be used to inform that decision?

Informed decisions

Primarily, it depends on whether the end customer demands MS approved connectors. If they do, buyers need only determine which brands to evaluate and place on print, bearing in mind it’s always wise to put two options down.

If the customer can use either product, determine if the application can withstand the relaxed technical specifications of a commercial equivalent. Find out whether the specs listed are a result of material, process, or labor aspects of the commercial equivalent connector.

Pricing must also be considered, so get quotes on both the commercial and MS approved parts and determine if the market for supply and demand is driving commercial pricing higher than MS style.

Some buyers may be faced with an existing supplier approvals strategy that dictates their vendor choices. Find out who has demonstrated supply success in that connector category and consult with other stakeholders such as production, engineering and product management to verify there is support for a given supplier.

Finally, establish whether availability is a prime consideration. There is often a plethora of military style products on a distributor’s shelves and sometimes not as much of the commercial equivalents. As a note, many authorized value-added connector assemblers can dual mark a part as commercial or mil spec, which offers greater sourcing flexibility. Speaking to a connector assembler that is on the qualified product list can help with advice and expertise throughout the process.