Aerospace and Automotive: Unexpected Uses for Spray Forming HSS

When most engineers hear "high speed steel" (HSS), they picture drill bits, end mills, and lathe tools — the workhorses of the machine shop. For decades, HSS lived almost exclusively in the cutting-tool aisle. So it is genuinely surprising that this same material class, made by an unconventional route called spray forming, is now showing up deep inside jet engines, landing-gear assemblies, transmissions, and turbochargers.

This post looks at how spray forming HSS quietly migrated from the tool crib to the vehicle and the aircraft — and why its unusual microstructure made that migration possible.

Aerospace: Where Spray Forming HSS Shows Up

Bearing and Actuator Components

Aircraft depend on bearings and actuators that survive millions of load cycles, often under lightly lubricated or start-stop conditions. Spray forming HSS — especially high-cobalt, high-vanadium grades — delivers bearing-grade hardness and fatigue resistance with a microstructure that resists the subsurface cracking that plagues coarser alloys. Used as rings, races, and precision preforms, it trims both weight and machining time versus solid-forged alternatives.

Landing Gear Wear Surfaces

Landing gear endures brutal fretting, corrosion, and impact. Rather than building an entire strut from an exotic alloy, manufacturers deposit an HSS wear layer onto a lower-cost substrate. The result is a true bimetallic part: tough and cheap inside, wear-proof outside.

Turbine and Hot-Section Hardware

Here is a genuinely counterintuitive use: because HSS retains hardness at elevated temperatures (its hallmark hot hardness), spray-formed variants are finding roles in auxiliary turbine components, compressor preforms, and valve or actuator parts that run hot but do not need full superalloy temperature capability. Spray forming lets engineers hit the sweet spot of cost, wear resistance, and heat tolerance.

Cryogenic and Structural Tubing

Spray forming can produce seamless thin-wall tubes and rings with uniform chemistry — useful for structural and fluid-system components where cleanliness and consistency matter more than peak strength.

Automotive: The Bigger, Quieter Revolution

The automotive sector consumes far more HSS tonnage than aerospace, so the savings scale accordingly. The use cases are also more numerous than most people expect.

Transmission Gears & Shafts

Spray forming HSS preforms cut machining scrap and deliver a finer, more fatigue-resistant microstructure — longer life in a smaller package for performance and heavy-duty drivetrains.

Valve Train & Turbo Parts

Valves, rocker arms, and turbo shafts run hot and wear fast. An HSS clad layer on a low-cost steel core keeps them alive as downsized, turbocharged engines push harder.

Diesel Injection Hardware

High-pressure fuel pumps and injector bodies demand extreme wear resistance. Spray forming HSS gives the needed surface durability without making the whole part from expensive stock.

MMC Edges

Inject ceramic particles (SiC, WC, TiC) into the spray to build an HSS-matrix composite in one step — material tailored for pump plungers and seat faces that destroy ordinary steel.

The Sustainability Bonus Nobody Talks About

A less-obvious but important benefit: spray forming is material-efficient. Wrought HSS can lose 70–90% of its mass to machining chips. Spray forming HSS is near-net-shape, so you discard far less expensive, energy-intensive alloy. For a high-alloy steel, that is a meaningful carbon and cost story — and one more reason the "unexpected" uses keep multiplying.

Where It's Headed

Expect spray forming HSS to keep creeping into places tool steel "shouldn't" go:

Additive-style repair & build-upFunctionally graded partsHybrid EV drive componentsBimetallic wear cladsOne-step MMC manufacture

• Repair and build-up of worn powertrain and aero components, extending part life.
• Functionally graded parts — HSS where it wears, ductile steel where it bends.
• Hybrid electric-drive components that need compact, durable, heat-loving materials.

From landing-gear wear layers to turbocharger shafts to injection plungers, a material once confined to the cutting-tool catalog is now quietly carrying loads, heat, and friction in the machines that move us.