Martin Frings
25 April 2024

“Pure Nickel, Pure Sound” might sound familiar to anyone who has visited our website or received a parcel from us… and we’re more than happy to back that up.

Recently, as part of routine external tests, we sent a stamper to the Sheffield Assay Office to test exactly how pure our stampers are.

The test consisted of Infrared Radiation Absorption, Plasma Spectrometry and X-Ray Fluorescence testing to work out exactly what is in a stamper.

We’re pleased to say that our stampers are 99.991604% pure nickel. The real figure is likely even purer than this but many contaminants were actually below measurable levels. 

You can see from the Assay report that the nickel that comes to us in its raw pellet form has a purity of 99.98562% (click here to view the report in detail). Whilst this is already extremely pure it shows that not only are we not adding any contamination during the plating process, we are actively purifying the nickel. Through careful management of pH we oxidise any iron out of the solution, and via constant low current density dummy plating, we remove many other metallic contaminants such as copper, lead and zinc.

If the nickel is so pure to begin with why does it matter that we’re removing any contaminants? 

The main reason for this is that contamination will have a compounding effect if it is not being removed. To give you an example of this; we once had a batch of nickel pellets which only had a purity of 99.92% – this sounds almost negligible, so how on earth could 0.06% make a difference?

To give this some context, let us suppose we top up a plating cell with 25kg of nickel on a weekly basis, this means that over the course of a month we have added 100kg of Nickel pellets with a purity of 99.92% – that remaining 0.06% of metallic contamination equates to 80grams of metallic contamination – this is the same as a small spanner.

This leads to the next question – so what if a small spanner gets tossed into the plating bath every month?

Contamination of even the smallest amount can dramatically impact the quality of a deposit. Whether that be poor ductility meaning that the stamper is so brittle it breaks after only a few impressions, or by creating other issues such as plating ‘blisters’ caused by poor adhesion in the plating bath, rough deposits that create low level rumbling on the pressed record, or in the extreme case a stamper so stressed it is bowed and hard to fit onto the mold to begin with. 

To give an idea of what kind of levels of contamination would cause an issue like this – in the case of iron or copper, a concentration of 200 parts per million would begin to create issues on the press, and with other metallics such as lead, even 10 parts per million can lead to issues.

As a pressing plant you don’t want to know if your stamper has 0.0005% copper content – you have an urgent order to get out the door and an important meeting with a new label. You simply don’t have the time to care about the nickel purity of your stamper, you just want a stamper that presses well. This is why we carry out these tests to ensure your stampers are nothing but pure nickel, pure sound.