A salt spray test places jewellery in a sealed chamber filled with a fine, warm salt mist for a set number of hours, then checks it for corrosion, discolouration and blistering. It is an accelerated test that shows how well the plating and coating protect the base metal.
The most widely used methods are ASTM B117 and ISO 9227. Labs in India that test metal finishes can usually run either.
What the test tells you
- Whether the plating has pores or thin spots where the base metal corrodes.
- Whether a lacquer or e-coat covers edges and recesses properly.
- How two suppliers or two finishes compare under the same conditions.
- Whether a bulk lot performs like the approved sample.
What it does not tell you
Salt spray does not convert neatly into months of real wear. A piece that survives a certain number of hours in the chamber will not necessarily last a matching number of months on a wrist. Real wear involves friction, sweat, cosmetics and cleaning, which the test does not reproduce.
It also says nothing about nickel, lead or cadmium compliance. Those need separate chemical tests.
How to set up the test
- Choose the method, such as ASTM B117 or ISO 9227, and name it in your order.
- Agree the test duration in hours. There is no single industry figure for jewellery, so set it by price point and test your approved sample first to see what is realistic.
- Define what counts as a pass, for example no visible corrosion or colour change on significant surfaces when viewed at a set distance.
- Test the same number of pieces each time, from different boxes in the lot.
When it is worth paying for
Salt spray testing is most useful when you launch a new line, change supplier or change finish, and as a periodic check on repeat orders. It is also useful for jewellery sold in hot, humid or coastal markets, where corrosion shows up faster.
For very low-priced trend pieces with flash plating, a full test on every lot is rarely worth the cost. A test on the approved finish is enough.
What this means for a buyer
Use salt spray as a comparison tool with a clear pass rule, not as a promise of wear life. Our guide to how plating thickness is tested covers the companion check.
Creston & Co works for buyers only, for a fixed fee agreed in writing. We arrange tests at NABL-accredited labs, compare results with your approved sample and supervise packing in Rajkot. Ask for a free sourcing review.