GMW3399M-ST-S CR 690T/550Y-DP Dual Phase — Cold Rolled Steel

GMW3399M-ST-S CR 690T/550Y-DP is a dual phase grade cold rolled steel conforming to the gm material specifications. At 550 MPa minimum yield strength, this is ultra-high-strength steel for door intrusion beams, bumper reinforcements, and tunnel structures, with high tensile capacity for safety-critical crash path components requiring controlled collapse behavior.

This specification carries the dual-phase (DP) designation under GMW3399M with ferrite-martensite microstructure for energy absorption in crash structures.

GMW3399M-ST-S CR 690T/550Y-DP is classified as a Dual Phase steel at 550 MPa yield and 690 MPa tensile. With 550 MPa yield and 690 MPa tensile, GMW3399M-ST-S CR 690T/550Y-DP targets high-energy crash structures where controlled deformation and energy absorption are critical design parameters.

Ameristeel stocks GMW3399M-ST-S CR 690T/550Y-DP in production-ready gauges and widths suited to high-strength stamping applications. As a 550 MPa yield cold rolled product, this specification is available in coil, sheet, and precision-blanked formats. Our ISO 9001:2015 certified facility triple-tests every coil (ID, OD, and center) to verify mechanical properties remain consistent throughout the entire length.

GMW3399M-ST-S CR 690T/550Y-DP is supplied with the following coating options: hot-dip galvanized (zinc) for general corrosion resistance; galvanneal (zinc-iron alloy) for superior paint adhesion and weldability; electrogalvanized for precise coating weight control and smooth surface finish. At 550 MPa yield, the coating selection for GMW3399M-ST-S CR 690T/550Y-DP should account for forming severity and post-stamping corrosion exposure in the final application.

GMW3399M-ST-S CR 690T/550Y-DP at 550 MPa yield and 690 MPa tensile compares to GMW3032M-ST-S HR550LA (0 MPa lower yield at 550 MPa) and GMW3399M-ST-S CR 980T/550Y DP (0 MPa lower yield at 550 MPa and 690 MPa vs 980 MPa tensile). Selecting the right grade depends on the balance between strength requirements and forming complexity for your specific stamping application.

GMW3399M-ST-S CR 690T/550Y-DP is an OEM-specific grade developed to meet General Motors engineering requirements for vehicle body and structural applications. Ameristeel supplies General Motors-specified steel grades directly to Tier 1 and Tier 2 automotive suppliers throughout Southeast Michigan, with full material traceability and third-party test reports on every coil. Our Fraser, MI steel processing facility maintains dedicated inventory of GMW3399M-ST-S CR 690T/550Y-DP to support just-in-time delivery schedules, and our ISO 9001:2015 quality system ensures that every shipment meets the exact mechanical property, surface quality, and dimensional tolerances required by General Motors production standards.

Ameristeel offers in-house processing for GMW3399M-ST-S CR 690T/550Y-DP at our Warren and Fraser, Michigan facilities. Available processing capabilities include precision slitting to custom widths on our multi-cut blanking line, cut-to-length sheet processing for exact dimensional requirements, laser cutting of high-strength profiles on our TRUMPF fiber laser with up to 4kW power, press brake forming on our TruBend series with up to 110-ton capacity and 120" bend length. From raw material sourcing through finished part delivery, Ameristeel provides a single-source solution — eliminating the need to coordinate between separate steel suppliers, service centers, and fabrication shops. Learn more about our laser cutting capabilities, production steel sales, or request a quote for processing GMW3399M-ST-S CR 690T/550Y-DP to your exact specifications.