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How to Blue Stainless Steel in 5 Easy Steps: Complete Guide

How to Blue Stainless Steel

Bluing is a process usually used by gun owners and firearms manufacturers to improve the aesthetic value of their weapons.

It provides the stainless steel surface with a layer of protection, giving rust and corrosion resistance while reducing potential glare as well.

I tried bluing one time and my gun lasted a lot LONGER than I thought! Plus, I loved its new, sleek look.

However, there are certain characteristics differences between the materials so knowing clearly how to blue stainless steel is really important.

If you want to learn how to blue a stainless steel object yourself, you’ve come to the right place.

All About Bluing Steel

First, let me go through a couple of bluing concepts that you have to know in order to achieve the desired result.

I tried restoring the bluish hue that one of my firearms had lost.

That’s when I learned that bluing steel is more or less a conversion of red iron oxide (Fe2O3) to black iron oxide (Fe3O4).

The name of the process actually comes from the blue-black appearance of the black iron oxide.

There are many methods you can use to blue the steel, including hot bluing, cold bluing, niter bluing, and so on.

In my case, hot bluing was the most accessible method as it involved heating the steel to high temperatures, which creates a deep, blackish-blue finish.

Stainless Steel

Due to the unique qualities of stainless steel, you can’t simply blue the material however you like.

Stainless steel can only tolerate hot bluing and a limited amount of chemicals.

Unless you have sufficient equipment and skill, it’s advised to let a professional perform the bluing for you.

High temperatures and dangerous chemicals mean that a moment of carelessness can make you pay a heavy price.

The use of stainless steel alloy varies a lot from one manufacturer to the other and that’s why the bluing effect won’t always be consistent.

I strongly advise that you only push through with this process if you are absolutely confident that you are able to perform the necessary precautions.

Necessary Gears and Tools

Necessary Gears and Tools

Safety first!

The ideal setup is a pair of long sleeve gloves along with splash goggles and a face mask.

I usually prepare roughly 6-8 tanks to perform bluing efficiently, but that may depend on the manufacturer’s manual.

I also have thermometers, stirrers, and something to heat up the tanks (usually gas burners).

An iron wire, stainless dipper, and part basket are required to handle the guns’ components and adjust the bluing solution as well. 

For the chemical, the bluing solution should be either Oxynate No. 84 or Du-Lite 3-0.

Besides those, you must also have water displacing oil and cleaning solution (Dicro-Clean 909).

Again, don’t mess around with these chemicals and only handle them with EXTREME attention.

Accidental exposure to the chemicals could result in serious injuries. Should something happen, seek medical help right away.

When everything is set up, put on your protective gear and then get down to business.


Step 1: Ready the Bluing Tank

Step 1

Fill the tank with a suitable amount of water then add in the bluing salt using the correct ratio.

Usually, you can find the manufacturer’s recommended ratio in the product manual.

After that, slowly and steadily stir the solution in the tank to dissolve the salt. Be careful since considerable heat might be generated in the process.

Remember to keep your gloves ON or else you’ll hurt yourself, like I did.

When you’re done, attach the thermometer to the tank and fire up the burner. 

Depending on what solution you use, the tank temperature must be maintained somewhere between 240 and 310 degrees Fahrenheit.    

It’s essential to keep stirring the tank to prevent the forming of hot and cold areas.

Once the solution reaches its boiling point, turn down the burner to about one-third of the boiling temperature and let it stay there.

Step 2: Process the Components of the Gun

Step 2

Prepare the components of the metal surface before you attempt to blue using your tools.

Excessive buffing on stainless steel could result in a grainy appearance so do it with care.

Next, suspend the components in a cleaning solution tank to get rid of dirt, oil, grease, and crud.

Keep them in that state while you heat them but be sure to NOT boil up the tank.

The temperature I used is 180 degrees Fahrenheit but it also depends on the manual.

Wait for 10 – 15 minutes and then take out the components. Rinse them in a cold water tank after.

After that, I use a soft brush to gently remove all the residue of the cleaning solution on the components.

Step 3: Suspend the Components in the Bluing Solution Tank

Step 3

Put all the components into the tank and wait for 5 – 15 minutes.

If the solution is still boiling vigorously, you can expect the bluing to happen naturally!

At first, I was unsatisfied with the bluing effect. To remedy this, I tried giving the components an acid bath (using Hydrochloric Acid).

They should start gassing up approximately 2 to 3 minutes after exposure.

You can put the components back into the bluing tank and increase the temperature until you see the blued steel.

Step 4: Rinse the Components in a Cold Water Tank Then Transfer Them to a Hot One

Step 4

Following the treatment in the bluing tank, relocate the components to a cold water tank.

Note that it has to be a DIFFERENT tank from the one you used for Step 2.

Let them cool down as you take a closer look at the bluing effect.

I always do a final check on every nook and cranny of the components to see if there is any discoloration or blemishes.

If everything appears good, then you can transfer the components into a hot water tank.

This will remove all the traces of the bluing solution and other chemicals.

Step 5: Submerge the Components in a Tank Filled With Water Displacing Oil

Step 5

For the final step, I let the components cool down in water displacing oil.

Take them out after a couple of minutes and then wipe them clean to remove excess oil. You can reassemble the gun after.

You should note that the blue layer is rather delicate so don’t treat it roughly. Wait for a day to let the bluing properly cure before you do anything else to it.


That’s about everything you need to know about stainless steel bluing. It’s a pretty straightforward process. 

Though it may seem tricky at first, you’ll be glad to have figured it out because knowing how to blue stainless steel will come in handy from time to time.

Now, using the information above, you should have little problem bluing your firearms on your own. Go on and start bluing!

FINAL TIP: You might also want to read my article on how to easily darken or blacken stainless steel or blacken stainless steel for more ways to personalize your gear.

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