Is the Carbon Steel Flange Connection Kit, DIN 931 suitable for outdoor use in corrosive environments?

Carbon Steel Flange Connection Kit, DIN 931 — suitability for outdoor use in corrosive environments: The kit is made from high-quality carbon steel with an electro-galvanized finish, which provides enhanced corrosion resistance compared to bare carbon steel. This makes it generally suitable for outdoor use and for environments with moderate corrosive exposure (e.g., occasional moisture, mild industrial atmospheres). However, electro-galvanization has limits: in highly corrosive environments (marine/coastal atmospheres with salt spray, chemical plants with aggressive acids/alkalis, or continuous wet/damp conditions) the zinc coating can degrade faster and may not provide adequate long-term protection. For such severe conditions stainless steel (e.g., A4/316) or more robust coatings (hot-dip galvanizing, duplex systems, or specialist corrosion-resistant treatments) are normally recommended. Conclusion: Carbon Steel Flange Connection Kit, DIN 931 is acceptable for outdoor use in moderate corrosive environments, but for high-corrosion or marine/chemical exposures choose stainless steel or heavier protective coatings for reliable long-term performance.

Can the Carbon Steel Flange Connection Kit, DIN 931 be used with stainless steel flanges without causing galvanic corrosion?

Short answer: Possibly, but with precautions. The Carbon Steel Flange Connection Kit, DIN 931 is made of electro‑galvanized carbon steel (bolts DIN931, nuts DIN934, washers DIN125A). When mated to stainless steel flanges, a galvanic couple can form: carbon steel (less noble) will corrode preferentially in the presence of an electrolyte, potentially causing accelerated corrosion of the carbon steel fasteners and undermining the joint. Factors that determine risk: - Environment: wet, salty or chemically aggressive environments greatly increase galvanic corrosion risk; dry/purely indoor air has much lower risk. - Area ratio: small carbon steel fastener area vs large stainless flange area increases corrosion rate of the carbon steel. - Coating condition: electro‑galvanization offers some protection, but if the zinc coating is damaged or worn, corrosion accelerates. - Electrical continuity and presence of electrolyte: insulated or sealed joints reduce risk. Mitigation measures: - Use isolation (non‑conductive washers/gaskets/coatings) to prevent electrical contact. - Apply protective coatings or corrosion inhibitors on fasteners and contact surfaces. - Use sacrificial protection or sacrificial zinc/galvanic anodes if appropriate. - Prefer matching materials: use stainless steel fasteners (recommended) for long‑term resistance to galvanic corrosion in aggressive or wet environments. Recommendation: For indoor, dry, non‑aggressive conditions the Carbon Steel Flange Connection Kit, DIN 931 may be acceptable with routine inspection. For outdoor, marine, chemical or long‑term installations, use stainless steel fasteners or implement isolation/corrosion control measures to avoid galvanic corrosion.

Set for connections flange, steel carbon, DIN 931

All products, Flange couplings/

Additional information

Set for connections flange (EN 1092), type SZ1. W set: screws DIN931 – 4 pcsi, a nut DIN934 – 4 pcsi and washer DIN125A – 4 pcsi. Class properties mechanical: 5.6 – screws; 8 – a nut; 140HV – washer. Selection of bolts and nuts for flanges according to the table in the attachment. Material: steel carbon, galvanized galvanically.

List of product variants

Article number	Product variant name	DN	BAR	Availability	Actions
TK-SZ1-M12-050-A-PG	Set (4 pcs) bolts M12x50, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M12-055-A-PG	Set (4 pcs) bolts M12x55, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M12-060-A-PG	Set (4 pcs) bolts M12x60, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M12-070-A-PG	Set (4 pcs) bolts M12x70, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M12-080-A-PG	Set (4 pcs) bolts M12x80, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-060-A-PG	Set (4 pcs) bolts M16x60, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-065-A-PG	Set (4 pcs) bolts M16x65, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-070-A-PG	Set (4 pcs) bolts M16x70, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-075-A-PG	Set (4 pcs) bolts M16x75, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-080-A-PG	Set (4 pcs) bolts M16x80, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-085-A-PG	Set (4 pcs) bolts M16x85, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-090-A-PG	Set (4 pcs) bolts M16x90, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-095-A-PG	Set (4 pcs) bolts M16x95, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-100-A-PG	Set (4 pcs) bolts M16x100, nuts, washers,galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-110-A-PG	Set (4 pcs) bolts M16x110, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M16-120-A-PG	Set (4 pcs) bolts M16x120, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M20-070-A-PG	Set (4 pcs) bolts M20x70, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M20-075-A-PG	Set (4 pcs) bolts M20x75, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M20-080-A-PG	Set (4 pcs) bolts M20x80, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M20-100-A-PG	Set (4 pcs) bolts M20x100, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M20-120-A-PG	Set (4 pcs) bolts M20x120, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M24-090-A-PG	Set (4 pcs) bolts M24x90, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M24-110-A-PG	Set (4 pcs) bolts M24x110, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M24-120-A-PG	Set (4 pcs) bolts M24x120, nuts, washers, galvanized steel	-	-	In stock	Enquiry
TK-SZ1-M24-140-A-PG	Set (4 pcs) bolts M24x140, nuts, washers, galvanized steel	-	-	In stock	Enquiry

Do you need a larger quantity of products or a bespoke quote?

Call us: +91 8 925 918 796 or email us: chennai@tubes-international.com

SEND ENQUIRY

Set for connections flange (EN 1092), type SZ1. W set: screws DIN931 – 4 pcsi, a nut DIN934 – 4 pcsi and washer DIN125A – 4 pcsi. Class properties mechanical: 5.6 – screws; 8 – a nut; 140HV – washer. Selection of bolts and nuts for flanges according to the table in the attachment. Material: steel carbon, galvanized galvanically.