5251 Aluminum Sheet
A medium-strength alloy with good formability is aluminum alloy 5251. It is well known that alloy 5251 has great ductility and is easily cold worked in the annealed condition. Additionally, it has a strong resistance to corrosion, particularly in marine conditions. This alloy has magnesium in it and is strengthened by cold working, with common tempers H22, H24, and H26.
Common applications for 5251 aluminum sheets and plates are:
- Boats
- Marine structures
- Aircraft parts
- Vehicle panels
- Furniture tubing
- Containers
Properties of 5251-H26
Proof Stress | >170 MPa |
Tensile Strength | ~ 250 MPa |
Brinell Hardness | 69 |
5251 Aluminum Sheet Fabrication
KDM manufactures numerous OEM items for various purposes using high-grade 5251 aluminum. Our engineers can design, fabricate, and deliver custom aluminum products for any application. Your 5251 aluminum sheet fabrication product will be available in various surface treatments like powder-coating, anodizing, and more.

The 5251 aluminum alloy has an ultimate tensile strength of 230-270 MPa, making it moderately strong when compared to other aluminum alloys.
Magnesium, with 1.7-2.4% content.
NS4 aluminum is another way of denoting 5251 aluminum.
H24 is the tempered type. In H24, the material is hardened by rolling, then annealing to half hard. In H26, it is hardened by rolling, then annealing to three-quarter hard. In H22, it is hardened by rolling, then annealing to quarter hard.
The specified strength of 5251 is less in the typical H32 and H34 tempers than it is in 5052 for the same tempers. The yield strength of 5251 is also significantly lower than that of 5052 because it has lower magnesium content.