Aluminum Classification: Each aluminum gate is constructed from 6061-T6 rust free wrought aluminum alloy. 6061-T6 wrought aluminum is a high-grade alloy with a yield strength of about 35,000 pounds per square inch. For comparison, this is much stronger than "mild steel" which has a yield strength at about 20,000 to 30,000 pounds per square inch (depending on quality of alloy). 6061-T6 wrought aluminum is used for the purpose of durability and resiliency, providing a quality dent resistance and lasting beauty. We chose this higher grade of aluminum for more strength, durability and lasting beauty. We take pride in the fact that our gates will stand up to the tough trials of shipping and still last a lifetime. Most aluminum gate manufacturers use 6063 aluminums, which is a weaker grade of aluminum and does not have the yield or resilience of 6061-T6. Other gate manufactures use this cheaper grade because they fail to see past the importance of the additional resiliency when driveway gates absorb the bumps of everyday life. A key test for gates is their resilience. Gates should be able to absorb pressure and then return to its original shape. To resist snapping, 6061-T6 alloy has a high level of pliability, much like an airplane wing. When pressure is exerted on the material it yields to the pressure, and when the pressure is released, it regains its original form.