Guidelines for Selection of Fasteners Based on Galvanic Action

®Fastener Metal®

Zinc & Galvanised Steel

Aluminium & Aluminium Alloys

Steel & Cast Iron

Brasses, Copper, Bronzes, Monel

Martensitic Stainless Type 410

Austenitic Stainless Types 302 / 304, 303, 305

¯Base Metal¯

Zinc & Galvanised Steel

A

B

B

C

C

C

Aluminium & Aluminium Alloys

A

A

B

C

NOT Recommended

B

Steel & Cast Iron

A D

A

A

C

C

B

Terne (Lead-Tin) Plated steel sheets

A D E

A E

A E

C

C

B

Brasses, Copper, Bronzes, Monel

A D E

A E

A E

A

A

B

Ferritic Stainless Type 430

A D E

A E

A E

A

A

A

Austenitic Stainless Types 302 / 304

A D E

A E

A E

A E

A

A

A

The corrosion of the base metal is NOT increased by the fastener

C

The corrosion of the base metal MAY be markedly increased by the fastener

E

The corrosion of the fastener is INCREASED by the base metal

B

The corrosion of the base metal is MARGINALLY increased by the fastener

D

The plating of the fastener is RAPIDLY consumed, leaving the bare fastener metal

NOTE:
Surface treatment and environment can change activity.