How Environmental Exposure Affects Screw Performance

Environmental conditions often dictate the lifespan of screws more than mechanical load. Exposure to moisture, salt spray, chemicals, and temperature fluctuations accelerates material degradation and increases failure risk.

Screw failures caused by environmental factors are common in marine, chemical, construction, and outdoor infrastructure applications.

Uniform Corrosion vs. Localized Corrosion

Uniform corrosion gradually reduces the cross-sectional area of a screw, weakening its load-bearing capacity. Localized corrosion, such as pitting or crevice corrosion, is far more dangerous because it concentrates stress in small areas.

Localized corrosion often leads to sudden fracture under normal service conditions.

Stress Corrosion Cracking (SCC)

Stress corrosion cracking occurs when tensile stress and corrosive environments interact. Stainless steel screws exposed to chloride-rich environments are particularly vulnerable.

SCC failures are difficult to detect and can occur at stress levels far below the material’s yield strength.

Coating Degradation and Failure

Protective coatings such as zinc plating, galvanizing, or organic coatings can fail due to mechanical damage, aging, or improper application. Once the coating is compromised, corrosion can rapidly attack the base material.

Designing Screws for Harsh Environments

Selecting appropriate materials, coatings, and installation practices is essential to minimizing corrosion-related screw failures in aggressive environments.