410 stainless steel may not be the biggest star among metal materials. As a low-cost, general-purpose stainless steel, it’s more of a solid choice than a sexy one.

But 410’s down-the-middle properties make it useful for lots of different applications. And as with all stainless steels, it has its fair share of heat treating challenges.

So let’s take a closer look at heat treating 410 stainless steel in this guide for getting great DIY heat treating results.

What Is 410 Stainless Steel?

410 stainless steel is a magnetic, martensitic stainless steel (composed of at least 50% iron) that’s corrosion resistant in mild atmospheric conditions, with moderate strength and hardness.

More info: Different Types of Stainless Steels

Important Properties

Wear resistance: Good edge retention after hardening, thanks to carbon content.

Corrosion resistance: Suitable for non-extreme conditions (non-acidic). For maximum corrosion resistance, choose a non-hardenable steel (without carbon), such as 304 stainless steel.

Machinability: After annealing, it’s relatively easy to machine and form (particularly compared to the harder 440C stainless steel).

Composition

The figures below are approximate and will vary slightly by supplier.

Common Applications

410 stainless steel is good for a wide range of projects that need mild corrosion and heat resistance, as well as high strength:

• Knives and other kitchen utensils
• Jewelry
• Hand tools
• Mechanical parts
• Pump shafts
• Valves and other engine components

410 Stainless Steel Heat Treatments

Heat treating 410 stainless steel includes annealing, hardening, and tempering.

The following is an overview of these processes. The right parameters for your project may vary. Always consult with the material manufacturer on the specific recipes for your application.

Annealing

Reduce internal stresses and improve machinability and formability.

1. Heat to 1525-1625°F and hold for a half-hour per inch of thickness.
2. Cool in the furnace at up to 45 °F per hour, down to 1100°F.
3. Remove from the furnace and cool to room temperature.

Hardening 

Maximize the tensile strength of your material.

1. Heat in the furnace to 1700-1850 °F.
2. Hold / soak for 30 minutes per inch of thickness.
3. Oil quench for slow, even cooling.

Tempering

Relieve internal stresses and improve toughness after the hardening process.

1. Reheat the workpiece in the furnace to one of two tempering temperature ranges: 400-700 °F or 1050-1125 °F.
2. Hold for at least two hours, plus 1 hour per inch of thickness over 2 inches.
3. Remove from furnace and allow to cool in ambient air.
4. The lower range will result in higher hardness (~45 HRC) but less toughness, while the higher temps will yield lower hardness (~27 HRC) but higher toughness.
5. Avoid tempering between these ranges because studies show negative effects on resistance properties at this level.

Key Considerations & Best Practices

Here are a few pointers to keep in mind as you get to know heat treatments for 410 stainless.

Keep it clean. Prepare your workpiece before heat treating by sanding off any scale and removing dirt and oil from the surface with a degreaser.

Also, consider using an argon gas kit with your furnace for easy cleanup after heat treatment. Argon treatments can prevent scaling and carbon buildup. This makes it so that your workpiece will be easier to clean up and your material will not need to be ground down.

Take the time to temper. It can be tempting to skip the temper and call your work done, but don’t overlook this process to reduce the brittleness of the metal and improve its toughness and ductility.

Test and verify. Since circumstances and parameters are different for every project, always check your hardness levels with a hardness tester after heat treating to make sure you get the results your application requires.

Be safe. It always bears repeating: heat treating is a hazardous process. Wear your personal protective equipment and choose tools that help keep you and your shop safe, such as Hot Shot's Cool-Touch technology.

Use purpose-built equipment. Temperature control is key to successful heat treating. Use a furnace designed for hobby heat treating needs, like Hot Shot heat treating ovens with precision temperature control.

Now that you have the 411 on 410 heat treating, it's time to test your skills, make something awesome with metal and ensure it’s built to last!