{"id":16341,"date":"2026-02-03T08:00:00","date_gmt":"2026-02-03T14:00:00","guid":{"rendered":"https:\/\/blog.misumiusa.com\/?p=16341"},"modified":"2026-02-03T16:05:27","modified_gmt":"2026-02-03T22:05:27","slug":"zinc-plating","status":"publish","type":"post","link":"https:\/\/blog.misumiusa.com\/zinc-plating\/","title":{"rendered":"What Is Zinc Plating? Benefits, Finishes, and Types"},"content":{"rendered":"\n
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Zinc plating delivers a corrosion-resistant, long-lasting metal finish that offers a cost-effective solution compared to other part materials, especially for fasteners.<\/p>\n\n\n\n

But if only zinc plating was that straightforward. There are four different types of zinc plating processes, multiple finishing options, and even alternatives. Let that \u201czinc\u201d in!<\/p>\n\n\n\n

This article dives into everything you need to know about zinc plating, so you can make the right choices when sourcing fasteners and other parts for your application.<\/p>\n\n\n\n

What Is Zinc Plating?<\/h2>\n\n\n\n

Zinc plating is a surface treatment<\/a> that involves an electrochemical process that adds a layer of zinc onto metal (often steel). The metal then takes on properties that the zinc has. Zinc plating is flexible as it can be applied at different thicknesses.<\/p>\n\n\n\n

4 Main Benefits of Zinc Plating<\/h2>\n\n\n\n

Not only does it make metal parts corrosion resistant, but it can also extend the part\u2019s lifecycle and is generally more cost effective to other materials, such as stainless steel.<\/p>\n\n\n\n

But hold up! Keep in mind that not all types of zinc plating are created equal. Some may offer great corrosion resistance but have a higher risk of toxic exposure \u2014 more on this later.<\/p>\n\n\n\n

1. Corrosion Resistance<\/h3>\n\n\n\n

Zinc creates a protective barrier by blocking moisture and oxygen from reaching the metal.<\/p>\n\n\n\n

2. Extended Life<\/h3>\n\n\n\n

Zinc plating extends the life of steel parts by providing sacrificial corrosion protection with the zinc corroding first while keeping the underlying steel protected.<\/p>\n\n\n\n

3. Cost Effective<\/h3>\n\n\n\n

Zinc-plated metal is cheaper than steel. It\u2019s also easy to apply in high volume.<\/p>\n\n\n\n

4. Versatile<\/h3>\n\n\n\n

Along with zinc plating being cost-effective, it\u2019s suitable for a wide range of environments, appearances, and fastener applications.<\/p>\n\n\n\n

Zinc Plating Finishes<\/h2>\n\n\n\n

There are two terms that tend to be used interchangeably: \u201cpassivation\u201d and \u201cchromate.\u201d The benefits are the same: to create a protective layer. But it\u2019s important to understand that the chemical processes of each are different and using them interchangeably may impact consistent quality.<\/p>\n\n\n\n

Passivation<\/h3>\n\n\n\n

Passivation, often referred to as \u201ctrivalent chromate,\u201d which is the process of applying a thin trivalent chrome coating over the zinc finish. This provides an added layer of protection.<\/p>\n\n\n\n

Zinc Chromate<\/h3>\n\n\n\n

Zinc chromate, often referred to as \u201chexavalent chromate,\u201d uses hexavalent chrome to create a thin layer above the zinc plating. This type of finish also creates an added layer of protection from corrosion.<\/p>\n\n\n\n

Different Types of Zinc Plating<\/h2>\n\n\n\n

As mentioned earlier, there are different types of zinc plating. Not all options are the same \u2014 some offer stronger corrosion-resistant properties, while others are highly toxic and not RoHS-compliant.<\/p>\n\n\n\n

1. Zinc Hexavalent Chromate Plating<\/h3>\n\n\n\n

Also known as \u201cyellow zinc,\u201d \u201czinc yellow chromate,\u201d or \u201chex chrome,\u201d this type of plating consists of a two-step system in which zing plating is applied to the base steel, and the hexavalent chromate conversion coating is formed on top of the zinc.<\/p>\n\n\n\n

This process produces a yellowish color but can also appear green, iridescent, or clear.<\/p>\n\n\n\n

This type is common because it\u2019s historically known for its high corrosion resistant and low cost. However, it is heavily regulated and not RoHS-compliant due to its toxic properties.<\/p>\n\n\n\n

2. Zinc Trivalent Chromate Plating<\/h3>\n\n\n\n

Also known as \u201czinc blue\u201d or \u201cRoHS zinc,\u201d this type consists of electroplated zinc followed by trivalent chromium (Cr\u00b3\u207a) conversion coating. Unlike yellow zinc, it\u2019s RoHS-compliant and less toxic. But the process comes with a higher cost, and it\u2019s not as corrosion resistant as yellow zinc.<\/p>\n\n\n\n

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Pan Head Screw with Flash Washer – Zinc Trivalent Chromate Plating<\/a><\/figcaption><\/figure><\/div>\n\n\n\n

3. Zinc Black Hexavalent Chromate Plating<\/h3>\n\n\n\n

More commonly known as \u201cblack zinc” or “black chromate,” this type has a hexavalent chromium (Cr\u2076\u207a) conversion coating. A small amount of silver nitrate is added to the chemical conversion treatment creates its black color.<\/p>\n\n\n\n

Some applications require black zinc because of its superior corrosion performance.<\/p>\n\n\n\n

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Pan Washer Head Phillips Drive Screw – Black Chromate<\/a><\/figcaption><\/figure><\/div>\n\n\n\n

4. Zinc Black Trivalent Chromate Plating<\/h3>\n\n\n\n

Also referred to as \u201ctrivalent black” but with a trivalent chromium (Cr\u00b3\u207a) conversion coating. It is not as corrosion-resistant as hexavalent but is less toxic, which makes it RoHS-compliant.\u00a0<\/p>\n\n\n\n

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Hex Socket Cap Screw – Trivalent Black<\/a><\/figcaption><\/figure><\/div>\n\n\n\n

Zinc Plating vs. Zinc Flake Coating<\/h2>\n\n\n\n

An alternative to zinc plating is zinc flake coating. Flake coating doesn\u2019t involve electroplating; instead, tiny flakes of zinc are applied to the base material. This creates a barrier that strongly prevents corrosion.<\/p>\n\n\n\n

This is a great option since it offers high corrosion resistance and no hydrogen embrittlement risk, making it a great choice for high-strength fasteners. The downside is that it costs more than zinc plating.<\/p>\n\n\n\n

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Hex Socket Cap Screw – Zinc Flake Coating<\/a><\/figcaption><\/figure><\/div>\n\n\n\n

Zing Plating \u2013 Side-by-Side Comparison<\/h2>\n\n\n\n

Here is an overview of the characteristics, strengths and weaknesses of each zing plating option.<\/p>\n\n\n\n

Finish<\/strong><\/td>Chemistry<\/strong><\/td>RoHS<\/strong><\/td>Corrosion Resistance<\/strong><\/td>Strengths<\/strong><\/td>Weaknesses<\/strong><\/td><\/tr>
Zinc trivalent (blue\/clear)<\/strong><\/td>Cr\u00b3\u207a<\/td>Yes<\/td>Medium<\/td>Cost-effective, widely available, RoHS compliant, predictable torque behavior<\/td>Lower corrosion resistance than hexavalent systems, often requires sealers for extended life<\/td><\/tr>
Zinc black hexavalent<\/strong><\/td>Cr\u2076\u207a<\/td>No<\/td>High<\/td>Excellent corrosion resistance, deep uniform black color, strong self-healing behavior<\/td>Non-RoHS, toxic chemistry, declining availability, regulatory restrictions<\/td><\/tr>
Zinc black trivalent<\/strong><\/td>Cr\u00b3\u207a<\/td>Yes<\/td>Med-High<\/td>RoHS compliant, safer chemistry, acceptable black appearance, compatible with sealers<\/td>Slightly reduced corrosion resistance vs hexavalent, color consistency can vary, higher cost<\/td><\/tr>
Zinc flake coating<\/strong><\/td>Zinc flakes in binder<\/td>Yes<\/td>Very High<\/td>Outstanding corrosion resistance, no hydrogen embrittlement risk, ideal for high-strength fasteners<\/td>Higher cost, thicker coating, limited color options, more industrial appearance<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
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Learn what zinc plating is, its key benefits, common finishes, and more.<\/p>\n","protected":false},"author":69,"featured_media":16342,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"footnotes":""},"categories":[1136],"tags":[],"class_list":["post-16341","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mechanical-design"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t