What’s stronger than steel? IAA’s CEO and President John Kett examines the growing usage of advanced high-strength steel (AHSS) in vehicles. As a stronger, lighter alternative to traditional steel, it could shake up the world of automotive manufacturing.

Steel is tougher than ever. So what’s stronger than steel?

If you guessed advanced high-strength steel (AHSS), you’d be right. Though perhaps not as flashy as several of the materials that have made their way into the automotive manufacturing process of late, AHSS has been embraced by the OEMs as a stronger, lighter alternative to traditional steels.

But what is AHSS? The technical definition is fairly simple. AHSS consists of any steel alloy with a minimum tensile strength of roughly 500-800 megapascals (MPa) and a maximum of 1,500. The result is a material that’s tougher than traditional steel alloys, without being nearly as heavy as one would expect. I’ll spare you the technical details for now, but it all has to do with the microstructure that’s left behind following the annealing process.

AHSS in manufacturing

Anyone working in the automotive industry is likely very familiar with the ongoing “aluminum war” taking place via the advertising campaigns of several major manufacturers. But while the OEMs have been drawing lines in the sand over the benefits and downsides of aluminum, nearly all of them have quietly implemented AHSS into their manufacturing processes. As of 2014, the average vehicle contained approximately 254 pounds of the matel, outpacing analyst predictions by nearly 20 pounds. And we’ll be seeing more of the material over the next decade, as experts anticipate its per-vehicle usage to nearly double to 483 pounds by 2025. At this point, you’d be hard pressed to find a vehicle that doesn’t contain at least some of the material.


For all its benefits, AHSS is causing headaches for collision repair shops and insurance carriers across the country. Traditional steels were a relatively forgiving material, offering technicians a variety of options during the repair process. Take a rear end collision resulting in minor frame damage, for example. With vehicles manufactured from common steels, this would have been fairly routine. Place the vehicle on a frame machine; apply force; stop once the vehicle meets manufacturer specs. But that’s not the case with AHSS. Many manufacturers have actually mandated that AHSS parts be replaced rather than repaired. Honda’s repair bulletin for the 2016 Civic provides a perfect example:

“The use of 1,500 MPa frame rails requires that they be replaced as complete assemblies at the factory seams, with no sectioning allowed.”

The primary concern with repairing AHSS is heat, something traditional steels were often exposed to during the repair process. Indeed, one of the material’s primary benefits, aside from its strength, was the fact that damaged components could be welded or heated to a pliable state during the repair process. But with AHSS, the application of heat actually weakens the material, and can lead to dangerously unsafe conditions.

Auction Effect

Much like aluminum, the proliferation of AHSS throughout the automotive manufacturing process is leading to more questions than answers when it comes to the materials impact on auction values. P&C carriers have historically relied on real-world data when setting premiums, and there simply isn’t that much of it to go around in the case of AHSS. We do know several things for sure, however, and we can connect a few dots on our own.

More complicated processes and the need to replace major parts that historically would have been repaired will likely impact costs. As these costs rise, total loss thresholds will almost certainly be impacted. Once total loss vehicles hit the auction lanes, however, things get a bit murkier. Manufacturers are utilizing a host of advanced materials to meet their lightweighting goals, often on the same vehicle. As such, it’s difficult to isolate the potential auction impact of any one composition. As with any developing situation impacting the automotive auction industry, IAA will continue to monitor results and report our findings to our partners.

Those of us in the automotive industry find ourselves living in interesting times. For all the pomp and circumstance surrounding the launch of a new or updated model, the technology underpinning the vehicles we drive had largely remained the same for decades. But seemingly overnight, that has changed. Rather than approach this transformation with doubt, however, I encourage everyone to welcome it with open arms. Trepidation will only prevent us from adapting to, and thriving in, our new reality. In a world which seems to lack anything permanent, perhaps change is the constant we’re searching for.

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