• ByRouging Solutions Editorial Team  ·  19 October 2026

ISO Standards for Stainless Steel Passivation: A Plain Guide

Picture a buyer's drawing that says "passivate to ISO", and a plant team trying to find the right number. Most people expect one big ISO rulebook for passivation, like ASTM A967. It does not exist. A handful of ISO standards touch the job, and each one does something different.

This guide walks through the ISO standards for passivation, what each one covers and which one fits your work. It also shows how they sit next to the ASTM and AMS rules you may already use.

Which ISO Standards for Passivation Actually Exist?

Four groups are worth knowing. ISO 16048 covers passivating stainless steel fasteners. ISO 8074 and ISO 8075 cover the surface of stainless parts for aircraft, with passivation as one step. ISO 15730 covers electropolishing, which smooths the steel and leaves it passive. ISO 13485 is the quality system many medical device makers use.

That surprises a lot of engineers. In the ASTM world, one document covers passivation for almost any stainless part. ISO splits the ground differently, so a single "ISO" note on a drawing is not enough to tell you what to do.

Each has its own job. Three are written for narrow groups of parts, either fasteners or aerospace parts. One is a finishing process that also leaves the steel passive, and the last is a system for running the business. It asks you to prove your processes work, but it does not tell you which chemistry to use.

Our guide to ASTM A967 covers the ASTM side in full. This guide stays with ISO.

What Does ISO 16048 Cover?

It covers stainless steel fasteners, such as bolts, screws and nuts. ISO's catalog says the standard "specifies the methods most often used for passivation of corrosion-resistant stainless steel fasteners." It is short, at four pages, and it deals only with this one kind of part.

The status is the part most buyers miss. ISO published ISO 16048 in February 2003, and it is still on its first edition. ISO's page says it "was last reviewed and confirmed in 2024. Therefore this version remains current" (ISO 16048). So a 2003 date on a drawing does not mean the standard is out of date.

ISO says it reviews a standard every five years. After a review, a standard can stay the same, be changed or be dropped. "Confirmed" means the experts looked at it again and kept it as it was.

The narrow scope matters more than the date. ISO 16048 targets fasteners. If someone cites it for a tank, a pipe loop or a pump casing, ask why. The method may still be sound for that job. The standard just was not written for it, so the scope is worth agreeing in writing.

What About ISO Standards for Aerospace Parts?

Two newer standards cover them. ISO 8074 and ISO 8075 both came out in May 2025. They set out how to treat the surface of stainless parts made for aircraft. Passivation is one step, done before the parts are checked, and each standard covers a different family of steel.

ISO 8074 is for austenitic grades, the family that holds the 300 series. Its catalog page lists "surface passivation" as one step, before the parts are tested (ISO 8074). ISO 8075 is for hard grades such as 17-4PH, and it lists the same step before the parts are inspected (ISO 8075).

Both are second editions. They replaced editions from 1985, which ISO lists as withdrawn. So an aerospace drawing that still quotes the 1985 versions needs updating.

Where ISO 15730 Fits

ISO 15730 is about electropolishing, and it counts a passive surface as part of the result. ISO's abstract says it covers "electropolishing as a means of smoothing and passivating stainless steel alloys". It also lists what the buyer must tell the finisher, what the work must meet and how to test it.

The current edition is ISO 15730:2023, published in May 2023 as the second edition (ISO 15730). It replaced the 2000 edition, which ISO lists as withdrawn. If an older document names ISO 15730:2000, it points at a version that ISO has replaced.

It names the steel families it covers. These are the S2, S3 and S4 number series, which group the main stainless steels, plus the precipitation hardened alloys, a set of high-strength grades. For the makeup of each grade, it points to ISO 15510, ISO's list of stainless steel compositions.

Reach for this standard when a part must be smooth and bright as well as passive. Electropolishing takes off a very thin layer of metal, so it changes the surface in a way a chemical soak does not. Our guide to electropolishing explains when that extra step is worth paying for.

Is ISO 13485 a Passivation Standard?

No. ISO 13485 is a quality system for medical devices. It does not tell you which acid to use, how long to soak a part or which test to run. Instead, it asks a device maker to control and validate the processes that affect the product. For many devices, that includes passivation.

ISO compares it with ISO 9001, the general quality system used in most trades. It says ISO 13485 puts more weight on "risk management, and effective process validation" (ISO 13485). The current edition is ISO 13485:2016, and ISO's page says it "was last reviewed and confirmed in 2025."

It also matters in the US market. The current text of 21 CFR Part 820, the FDA's quality system rule for devices, refers to "ISO 13485 (incorporated by reference, see § 820.7)". In plain words, the FDA rule adopts the ISO text as part of the rule. Section 820.7 names ISO 13485:2016 as the edition.

So a device maker who works to ISO 13485 picks a separate method for the passivation step, such as ASTM A967. ISO 13485 then asks for proof that the step works, a written record, and tight control over how it is done. Our note on medical device surface finishing shows how those pieces fit together.

How Do ISO Standards Compare With ASTM and AMS?

They cover less ground. ASTM A967 sets the treatments and the pass tests for most stainless steel parts. ASTM A380 sets out how to clean, descale and treat them. AMS 2700 is for aerospace. The ISO passivation steps are written for narrow groups, fasteners in ISO 16048 and aerospace parts in ISO 8074 and 8075.

For general plant equipment, buyers often name ASTM A967 and ASTM A380 together. Our guide to ASTM A380 explains how it works as a pair with A967. Aerospace buyers often name AMS 2700, which our AMS 2700 guide covers, and some aerospace orders quote ISO 8074 or ISO 8075.

An ISO number tends to appear for one of four reasons. The part is a fastener, or it is an aerospace part. The part needs electropolishing. Or the customer runs ISO 13485 and wants the passivation step to sit inside their quality system.

Which ISO Standards for Passivation Should a Purchase Order Name?

The one that matches the part, with its year. Name ISO 16048 for fasteners, ISO 8074 or 8075 for aircraft parts, and ISO 15730 for electropolished parts. For other stainless kit, an ASTM method is usually clearer. Then add the test and the papers you need.

A short checklist helps you write it down:

1. Name the standard and its year. Write "ISO 15730:2023", since the 2000 edition has been withdrawn.
2. State the part and the steel grade. Say what you want treated and what it is made of.
3. Name the test. Agree how you will check the result before the work starts.
4. Ask for the records. List the documents you expect back, so nothing is missing at an audit.
5. Say where the work happens. Some jobs are done at your site and some at the supplier's premises.

ISO 15730 itself sets out the information the purchaser has to give the finisher, so the buyer's side of the order matters. A vague order leaves the choices to someone else, and they may not choose what you would.

Our team can passivate or electropolish your steel at your site or ours. We hand you the job records at the end. Our mechanical and electropolishing services page lists what we cover.

Where to Start

ISO has no single rulebook for passivating stainless steel. Of the ISO standards for passivation, use ISO 16048 for fasteners and ISO 8074 or 8075 for aircraft parts. Use ISO 15730 when the part is electropolished. For most other work, name an ASTM method.

This week, pull up one drawing or order that says "passivate to ISO". Check which standard it names, and if the year is there. If it is not clear, fix it before the next job goes out.

If you would like a second view, talk to our team. We reply within 24 hours.

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