Forged pistons are made by heating aluminum to 400°C+ and forming it under high pressure. The metal grain flows along the shape, creating a denser, stronger part. Cast pistons use molten aluminum poured into a mold — the grain structure is random and can have porosity. Forged strength is 30-50% higher, at a higher cost.

We use hot forging. 2618 aluminum is heated to 400-500°C, forged under high pressure, then T6 heat treated (solution + artificial aging), followed by full CNC machining to final dimensions. Every step has quality checks.

Forged rods: 4340/4140 steel bar → forged to shape → heat treated (quench + temper to 38-42 HRC) → CNC machining → shot peening → magnaflux inspection. Cast rods: molten steel poured → cooled → normalized → rough machining. Forging aligns the grain flow along the rod shape, giving far better fatigue strength.

Piston outer diameter: ±0.005mm. Pin bore: ±0.003mm. Skirt profile: CNC elliptical turning. Rod big end bore: ±0.005mm. Rod small end: ±0.003mm. Center-to-center: ±0.025mm. All finished parts are CMM verified.

Yes, every rod. Shot peening creates a compressive residual layer 0.2-0.5mm deep on the surface, which can increase fatigue life by 100%+. Many budget rods skip this step — we never do.

2618 aluminum (heat resistant to ~300°C, high strength, for high boost/RPM) and 4032 aluminum (12% silicon, low expansion, tighter clearance, for street/mild builds). We primarily recommend 2618 for performance applications.

OEM pistons are mostly cast aluminum (A380/332) — lower strength, heavier, lower heat tolerance. 2618 is aerospace-grade forged aluminum, originally used in aircraft engines. It retains 80% of room-temperature strength at 400°F. This is why we can support 500+ whp reliably.

4340 chromoly steel (most popular, high strength/toughness) — 300-1,200 HP. 300M steel (40% stronger than 4340) — 800-2,500+ HP. Titanium Ti-6Al-4V (44% lighter than steel) — 500-1,500 HP, high-RPM NA builds. See our Material Selection Guide.

OEM rods are typically cast ductile iron or forged 40Cr/40MnB. 4340 is aerospace-grade ultra-high-strength steel with 1,800-2,000 MPa tensile (2-3x regular carbon steel). It won't fatigue at high RPM like OEM rods will.