7075 aluminum plate is selected for high-strength structural components, aerospace tooling, molds and precision-machined parts. T651 and T7351 are both stress-relieved plate tempers, but their aging treatments target different balances of strength, toughness and resistance to stress-corrosion cracking.
Understanding T651 and T7351
The T6 and T7 temper families refer to solution heat treatment followed by artificial aging. The additional 51 suffix indicates stress relief by controlled stretching for plate. This reduces—but does not eliminate—residual stress and machining distortion.
- T651: solution heat-treated, stretched for stress relief and artificially aged toward a high-strength condition.
- T7351: solution heat-treated, stretched and overaged/stabilized to improve stress-corrosion resistance.
7075-T651 vs T7351 Comparison
| Factor | T651 | T7351 |
|---|---|---|
| Primary priority | High strength | Improved stress-corrosion resistance |
| Aging direction | High-strength artificial aging | Overaged/stabilized |
| Typical evaluation | Machined parts and high-load structures | Thick sections and corrosion-sensitive structures |
| Buyer must confirm | Strength, toughness and distortion limits | SCC requirements and approved design values |
Strength Versus Stress-Corrosion Resistance
Peak-aged 7075 offers very high strength, but sustained tensile stress in a corrosive environment can increase susceptibility to stress-corrosion cracking. The T73 aging family trades part of the peak-strength level for improved SCC resistance. The correct choice depends on applied stress, grain direction, environment, protective finish and inspection plan.
Do not compare tempers using a single tensile value. Yield strength, elongation, fracture toughness, fatigue, exfoliation and SCC requirements may all influence an aerospace or critical structural decision.
Machining and Dimensional Stability
The 51 stress-relief designation helps control residual stress in plate, but distortion can still occur when removing large volumes of material or machining asymmetrically. Buyers should define plate thickness, machining allowance, flatness, ultrasonic quality and grain direction. Balanced rough machining and intermediate stabilization may be needed for precision parts.
Application Selection
Aerospace Structures
Use the temper explicitly approved by the drawing and material specification. Strength, toughness, SCC resistance, fatigue and traceability requirements must be satisfied together.
Molds and Precision Tooling
T651 is frequently evaluated where strength and machinability are priorities. Thick plates require attention to through-thickness properties and distortion control.
Corrosion-Sensitive High-Load Parts
T7351 may be preferred when sustained stress and environmental exposure make SCC resistance a major design factor.
Standards and RFQ Checklist
ASTM B209/B209M covers aluminum-alloy sheet and plate. ANSI H35.1/H35.1M defines alloy and temper designations. Aerospace orders may require additional specifications and purchaser-defined tests.
- 7075-T651 or 7075-T7351
- Standard, revision and required approvals
- Thickness, width, length and tolerances
- Grain direction and mechanical-property requirements
- Ultrasonic inspection and acceptance class
- Fracture toughness, corrosion or SCC requirements when applicable
- Surface finish, protective film, marking and traceability
- MTC, third-party inspection and packaging
For product details, review 7075-T651/T7351 aluminum plate.
Frequently Asked Questions
Is T7351 stronger than T651?
Normally the selection advantage of T7351 is improved SCC resistance, not higher peak strength. Use certified requirements for the ordered thickness and standard.
Can T651 be substituted for T7351?
No substitution should be made without engineering approval. The tempers have different aging objectives and design allowables.
Does stress relief eliminate machining distortion?
No. Stretch stress relief reduces residual stress, but stock removal, part geometry and machining sequence still affect distortion.
Send temper, dimensions, quantity, inspection class and documentation through the SASA ALUMINUM 7075 plate page.
Post time: Aug-11-2026