If you’ve ever worked with components that take a beating—think crusher jaws, bucket teeth, or rail crossings—you’ve probably run into Hadfield steel. Known for its ability to get tougher the more you abuse it, Hadfield steel is one of the most unique and misunderstood materials in the welding world.

In this post, we’ll break down what Hadfield steel is, why it performs like no other, and how to weld it correctly to avoid cracking, brittleness, and premature failure.

What Is Hadfield Steel, and Why Is It So Tough?

Back in 1882, a British metallurgist named Sir Robert Hadfield discovered something revolutionary: a type of steel that thrives under impact. He combined high levels of manganese (10–14%) and carbon (1.0–1.4%) and created a steel that hardened the more it was pounded or hit. That’s how Hadfield steel, also known as austenitic manganese steel, was born.

Unlike regular steel, Hadfield steel doesn’t get harder through heat treatment—it actually becomes brittle when overheated. Instead, it gets stronger through work hardening, a process where the surface hardens under repeated impact or stress.

How Hadfield Steel Behaves in Service

Hadfield steel comes from the mill in either rolled or cast form. Initially, it’s relatively soft—about 187 Brinell in hardness. But with use, especially under high impact, its surface hardens up to 550 Brinell while the core stays tough and ductile.

That self-renewing toughness makes it ideal for components exposed to severe impact and wear. Every time the outer layer wears down, a new layer work-hardens from underneath.

Where is Hadfield Steel Used

Hadfield steel is used where impact resistance is critical:

• Power shovel bucket lips and teeth
• Crusher jaws and mantles
• Railroad frogs, switches, and crossings

It excels in environments with pounding or gouging wear, often lasting 10 times longer than mild steel under those conditions.

Key Properties of Hadfield Steel

Hadfield steel isn’t like your typical carbon steel. Here’s how it stands out:

• Thermal Expansion: Expands ~50% more than carbon steel when heated
• Thermal Conductivity: Only about 1/7 as efficient as carbon steel
• Electrical Conductivity: Roughly 1/7 that of carbon steel
• Melting Point: ~2,450°F (1,343°C)
• Magnetism: Non-magnetic unless heavily cold-worked

Caution: Hadfield steel becomes brittle if exposed to temperatures over 500°F without proper post-treatment. Extended heating between 500–800°F can degrade its toughness.

How to Weld Hadfield (Austenitic Manganese) Steel

Welding Hadfield steel is different than regular low carbon mild steel —and mistakes can be costly. There are two main types of welds you’ll encounter with Hadfield steel:

1. Build-Up Welds – For restoring worn surfaces (e.g., bucket lips, rails)
2. Strength Welds – For structural joints (e.g., repairing cracked buckets or joining manganese parts in production)

Use Only Arc Welding—Avoid Oxyacetylene

Arc welding is the only recommended method. Common processes are:

• Shielded Metal Arc Welding (SMAW)
• Submerged Arc Welding (SAW) with an alloy flux
• Gas Metal Arc Welding (GMAW)

Avoid oxyacetylene welding—it keeps the material hot for too long.

Electrodes for Hadfield Steel

Electrodes depositing 11–14% manganese are available in:

• Bare rods – Rolled or drawn from manganese steel, or tube rods filled with metal powders
• Shielded rods – Coated manganese rods or wires with alloying metals in the coating

Despite advancements in welding technology, bare rods still have a place in Hadfield steel welding due to their unique behavior.

Welding to Build Up Worn Surfaces

When rebuilding surfaces:

• Use high manganese electrodes that include molybdenum and copper for impact resistance
• If the part won’t get enough impact to naturally harden, cap it with a high-carbon chromium electrode for immediate abrasion resistance
• For large build-ups, use manganese steel applicator bars. Tack them down with coated electrodes, then fill in with bare rods

Peening (light hammering while the weld is hot) isn’t required for every job, but it:

• Helps control warping and cracking
• Hardens the top layer
• Reduces finishing work by smoothing the final pass

Note: A pre-hardened, peened surface may resist further work hardening during service. That’s good or bad depending on the application.

Welding to Join Manganese Steel Parts

When performing structural or strength welds, follow these best practices:

Keep Heat Input Low

• Most Hadfield steels contain over 1% carbon—excess heat will embrittle the metal
• Use low current and fast travel speeds to limit heat input
• Let the part cool frequently—after every half electrode if needed
• Keep the workpiece cool with water, but don’t quench the weld itself

Choose the Right Electrodes

• Use high manganese electrodes with molybdenum and copper
• For max strength, you can use 18-8 stainless steel electrodes—but keep in mind these welds can’t be cut with a torch (you’ll need plasma or powder cutting)

Welding Technique Recommendations

• Make wide, short beads to reduce heat concentration
• At the end of each weld, move the arc off to the side to create the crater, then fill it—this prevents crater cracks
• Peen multi-pass welds while hot to control distortion and avoid cracking

Hadfield steel is unlike any other alloy. It’s tough, self-hardening, and ideal for components that take a pounding. But that toughness comes with strict rules for welding and fabrication. Treat it like regular steel, and you risk ruining your part. Follow proper procedures, and you’ll get a component that performs far beyond what most steels can handle.

Have you ever welded this special type of steel alloy? What was your experience with it?

Reference: Metals and How to Weld Them