Stainless Steel Shims vs Carbon Steel Shims

Choosing the right shim material is essential for pipeline longevity and safety. The two most common shim materials in pipeline construction are stainless steel and carbon steel. Each has distinct advantages depending on the application, environment, and project specification.

Stainless Steel Shims

Stainless steel shims offer superior corrosion resistance and are required when shimming stainless steel piping to prevent galvanic corrosion. Common grades include:

• 304 stainless steel — general purpose, good corrosion resistance
• 316 stainless steel — superior corrosion resistance for marine and chemical environments
• 301 stainless steel — high strength, good for spring applications

Carbon Steel Shims

Carbon steel shims are the most economical option and are suitable for non-corrosive environments or where protective coatings are applied. They offer:

• Lower cost per shim compared to stainless
• Higher hardness in some grades
• Easy to weld and fabricate
• Suitable for indoor or protected environments

When to Use Each Material

• Use stainless steel shims when: shimming stainless piping, in corrosive environments, near saltwater, in chemical processing, or when the specification requires it
• Use carbon steel shims when: shimming carbon steel piping in protected environments, cost is a primary concern, or where coatings will be applied
• Use galvanized shims when: moderate corrosion protection is needed at lower cost than stainless

Other Shim Materials

• Brass shims — for electrical isolation between dissimilar metals
• Aluminum shims — lightweight, corrosion resistant, low cost
• Copper shims — excellent thermal conductivity
• Plastic/composite shims — for electrical isolation and vibration dampening