Corrosion Categories and Material Selection Guide
C1-C5 corrosion categories per EN ISO 12944, anchor and fastener material selection: HDG, A2, A4, A5 stainless steel comparison.
EN ISO 12944 Corrosion Categories
C1: heated interiors. C2: unheated, rural. C3: urban, moderate industrial. C4: industrial, coast 200m-1km. C5: seaside <200m, heavy industrial.
Material Selection
C1-C2: HDG sufficient. C3: HDG or A2. C4: A4 mandatory. C5: A4 or A5 Duplex. Alcodec: A4 standard outdoor, HDG option indoor.
Galvanic Corrosion
Aluminium + steel contact: EPDM isolation gasket required. Alcodec: EPDM standard on all base plates.
