What is chemical etching?

Chemical etching is a metal engraving process that uses a chemical spray to remove material and create a permanent etched image. It's also known as chemical milling, photo etching, photo chemical, or chemical machining.
Chemical etching is a multi-step process:
1.A mask or resist is applied to the surface of the material.
2.The metal sheet is sandwiched between photo-tools and exposed to ultraviolet light.
3.The ultraviolet light hardens selected areas of the laminate into an acid-resistant surface.
4.The sheet is developed and any unexposed laminate is washed clear.
5.A corrosive chemical (etchant), which is normally some form of acid, is used to dissolve unwanted material away to produce the final design.
Chemical etching can create complex and highly accurate precision components from almost any metal. The strength of the acid determines the speed of the etching process. For example, ferric chloride may be used for etching copper or zinc plates, whereas nitric acid may be used for etching zinc or steel plates.

We have been at the forefront of etching technology for almost 20 years. This is because our unmatched chemical etching process know-how enables us to offer a fast, economical, quality-assured etching service for the widest range of metals.

Chemical etching benefits

With chemical etching, manufacturers are enabled to create metal parts even with the most difficult and intricate of designs, all while achieving high repeatability and consistent production quality.
We use low-cost, automated digital tooling which can be created and changed extremely quickly and cost-effectively. This ensures risk-free prototyping without financial penalty.
Photo-etched components are burr and stress-free with no mechanical force or heat used, leaving material properties unaltered.
Because component features are etched all at the same time, we can offer almost limitless part complexity to micron accuracy. Company logos, part numbers or serial numbers can also be etched into the surface of the component during manufacture at no additional cost.

Our full range of service benefits include:
  • Unlimited complexity – you only pay for the first hole
  • No expensive hard tooling
  • Low-cost design iterations
  • Burr and stress-free – metal properties unaffected
  • Lead-times in a few days – quicker on request
  • Almost any metal, including those typically hard to machine
  • Micron accuracy
  • Company logos, part numbers or serial numbers etched at no additional cost

What materials can be chemical etching?

We process more than 100 tonnes of sheet metal from over 2,000 metal types each year – more than any other chemical etching supplier. Our customers benefit from these purchasing economies and the wide variety of metals we hold in stock. Typical materials include:

Chemical etching process: 10 frequently asked questions

Want to ask a question about chemical etching or share a component drawing for technical review?

Q1. What is the chemical etching process?
The chemical etching process is a sheet metal machining process that is used to manufacture complex components with high levels of accuracy.Comprising nine steps, it works by printing the component design onto a photoresist mask which is laminated onto the metal.
The areas of photoresist which have not been printed are developed, exposing the metal, which is subsequently etched away.
Q2. What metals can be chemically etched?
Almost any metal and metal alloy can undergo chemical etching. This includes steel and stainless steels, nickel, copper, aluminium.
What makes photochemical etching so effective is that it works well on hard-to-machine metals, including highly corrosive-resistant metals such as titanium and its alloys.
Q3. What chemical is used in etching?
Most metals are etched using ferric chloride, a safe to use, recyclable etchant. Ferric chloride can be regenerated and reused.
Other proprietary etchants such as nitric acid, are used for specialist metals and alloys.
Q4. What sheet sizes and thicknesses can be etched?
Sheet metals between 0.010mm and 1.5 mm thick can be etched. The thicker the sheet the longer it takes to etch, meaning metals above 1.5mm are uneconomical to process.
Q5. How accurate is chemical etching?
Excellent accuracy can be achieved with photochemical etching. Standard minimum etching tolerances are ±10% of the metal thickness being etched, to a minimum of ±0.025 mm.
With development, greater accuracy can be achieved so it is encouraged that customers partner with TONGJIN Etching early in the design phase so an appropriate etching method can be developed.
Q6. What are the benefits of chemical etching?
Chemical etching is highly advantageous and offers many benefits. This process does not use mechanical force, unlike stamping which subjects sheet metals to extreme pressures. Nor does it put thermal stress on the cutting edge, unlike laser cutting.
Alongside this, chemically etched parts remain flat, burr- and stress-free, leaving the material properties unaffected.
Chemical etching can also produce very accurate engraved features at the same time the material is being profiled, such as fluidic channels, logos or part numbers. These features come at no additional cost.
Q7: What level of detail can chemical etching achieve?
The minimum standard etched opening achievable is 0.1 mm, but with development, etching can achieve even finer features.
Q8. How much does chemical etching cost?
Chemical etching uses digital tooling which is inexpensive, very easy to adapt and does not wear out, unlike presswork tooling.
Material thickness and component size are key cost drivers as you pay by the sheet, not by the part – the more parts per sheet, the lower the unit price. Thicker sheets take longer to etch and this is reflected in the cost of the component.
Q9. What are the maximum quantities chemical etching can produce?
There is no maximum quantity that chemical etching can produce.  Low-cost digital tooling ensures prototype quantities can be supplied quickly and economically.
As one of the largest sheet metal etching companies in the world, TONGJIN Etching supplies its customers with component quantities measured in the millions.
Q10. How long does chemical etching take?     
Chemical etching lead times are measured in days, not weeks or months, unlike traditional metal machining technologies.
Subject to quantities required and capacity, standard components which require no additional post-processing can be supplied in less than two working weeks. Urgent demands can be supplied even quicker.

Customer Reviews

I am extremely impressed with the precision...
Swapnil from United StatesWednesday, Jan 26, 2019
"I am extremely impressed with the precision and quality of the chemical etching performed by your team. The intricate designs on our metal components were etched flawlessly, exceeding our expectations. Thank you for delivering such a high-quality product."
Your chemical etching service has significantly improved the durability...
Sarah from United KingdomWednesday, Jan 20, 2020
"Your chemical etching service has significantly improved the durability and functionality of our products. The etched patterns not only enhance the aesthetics but also provide excellent grip and tactile feel. Our customers are thrilled with the results, and we couldn't be happier with your exceptional craftsmanship."
We have been relying on your chemical etching expertise for several projects...
Eduardo from ItalyWednesday, Mar 16, 2022
"We have been relying on your chemical etching expertise for several projects, and each time, you have consistently delivered outstanding results. Your attention to detail, quick turnaround time, and excellent customer service make you our preferred choice. Your commitment to excellence is commendable."
has given our brand a unique edge in the market...
Taner from TurkeyFriday, April 26, 2023
"The chemical etching performed by your team has given our brand a unique edge in the market. The intricate logos and designs etched onto our products have attracted significant attention and set us apart from our competitors. We appreciate your professionalism and skill."

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