RoHS and REACH for Custom Parts

RoHS, the Restriction of Hazardous Substances directive, restricts ten substances in electrical and electronic equipment placed on the EU market: lead, mercury, cadmium, hexavalent chromium, two brominated flame retardants and four phthalates. The limit is 0.1 percent by weight in any homogeneous material, except cadmium at 0.01 percent.

The phrase that matters is homogeneous material. Compliance is not assessed on your assembly or even on your part; it is assessed on each individually separable material within it. A plated finish is its own homogeneous material, and so is the base metal underneath.

REACH is a chemicals regulation rather than a product one. For a custom part its practical obligation is the Substance of Very High Concern list, currently well over two hundred entries and updated twice a year. If an article contains an SVHC above 0.1 percent by weight, you must pass that information down the chain, and on request to a consumer within 45 days.

RoHS applies to electrical and electronic products. REACH applies to essentially everything, which is the part buyers most often miss.

Bare machined aluminum and stainless are almost never the problem. The problems live in the finish, the fasteners and the free machining additives.

Hexavalent chromium is the classic one. Traditional chromate conversion coating on aluminum, sometimes still called Alodine or chem film, historically used hexavalent chromium, which RoHS restricts. Trivalent chrome alternatives exist and are widely available, but a drawing that says only chromate conversion coating leaves the choice to the shop.

Lead is the second. Free machining brass such as C360 contains lead deliberately, typically around 2.5 to 3.5 percent, because it is what makes the alloy machine so well. Leaded steels such as 12L14 are the same story. Both are far above the RoHS threshold, and both are extremely common defaults when a drawing just says brass or free machining steel.

After that: cadmium plating on fasteners, hexavalent chrome passivates over zinc plating, and PVC or phthalate-containing seals and cable jackets.

A supplier saying the part is compliant is not compliance. What you need is evidence that survives an audit or a customer questionnaire, and it is far cheaper to request at RFQ than to chase after delivery.

Ask for a RoHS declaration of conformity naming the specific part or material, not a generic company statement. Ask for the material certificate, which gives the actual chemistry and lets you check lead yourself. Ask for the finish specification including the passivate type, since that is where hexavalent chromium hides. For REACH, ask for an SVHC declaration stating whether any listed substance is present above 0.1 percent by weight, and against which version of the candidate list.

That last detail matters more than it sounds. The SVHC list grows twice a year, so a declaration against a 2023 list says nothing about substances added since. Ask for the list version and the date.

Where a part is genuinely critical, third party test reports exist, typically XRF screening for RoHS. They cost real money and are usually reserved for parts where a customer demands them.

Compliance is mostly free if you specify it up front and expensive if you retrofit it.

Specified at RFQ, the cost is usually a slower machining alloy or a slightly different finish. Lead free brass machines noticeably slower than C360, so expect a real cycle time increase on turned parts, and trivalent chromate is broadly comparable in price to hexavalent.

Discovered after production, the cost is the whole lot. There is no rework path from leaded brass to lead free, and a part already plated with a hexavalent passivate has to be stripped and replated at best. This is the failure that turns into a scrapped run and a missed ship date.

The documentation itself is cheap. A shop that already runs compliant materials produces declarations as a matter of course. A shop that has never been asked will take longer, which is itself a useful signal at RFQ stage.

The obligation sits with whoever places the product on the market, which for a hardware company means you, not your machine shop.

This surprises teams who assume a compliant supply chain is something they buy. What they buy is evidence; the declaration of conformity for the finished product is theirs to sign. That is why the documents matter: your file has to demonstrate that you did the work.

Practically, that means a technical file holding the bill of materials, a compliance status per part, the supporting declarations and certificates, and a record of when each was collected. Assembling that at the end of a program is painful. Collecting it per part as you release drawings is not.

It also means the question belongs in supplier selection. A shop that cannot produce a material certificate is a shop that cannot support your compliance claim, whatever it says about its own practices.

RoHS started in the EU but the pattern spread. China RoHS, UK RoHS after Brexit, and several other jurisdictions run comparable restrictions with their own paperwork and marking rules. The substance lists overlap heavily, so a part built to EU RoHS usually satisfies the others, but the declarations are separate.

California Proposition 65 is a different mechanism worth knowing: it requires warning labels rather than restricting content, over a much longer substance list, and it is enforced by private litigation. It catches products that are perfectly RoHS compliant.

Conflict minerals reporting under Dodd-Frank covers tin, tantalum, tungsten and gold, and applies to sourcing origin rather than to hazardous content. If your product contains any of those, expect the questionnaire.

None of these change how you specify a machined part. They change how many declarations you collect for it, which is an argument for asking once, at RFQ, for everything.

Put the requirement on the drawing rather than in an email. A note reading RoHS compliant, trivalent chromate only, no leaded alloys removes every ambiguity that causes a scrapped lot.

Name the finish precisely, including the passivate type, and say explicitly if free machining alloys are prohibited, because they are the default a shop will otherwise reach for on turned parts.

Then ask four questions at RFQ. Can you provide a RoHS declaration of conformity for this specific part? Can you provide a material certificate showing actual chemistry? What passivate is used on this finish, and is it trivalent? And can you declare SVHC content above 0.1 percent, against which version of the candidate list?

A supplier who answers those four without hesitation has done it before, which is worth as much as the documents themselves.