Stainless Steels

Information on stainless steels

Stainless steel is defined as a steel alloy with a minimum of 11,5% chromium content. This chromium part forms a passive film of chromium oxide, which prevents further surface corrosion and blocks corrosion from spreading into the metal‘s internal structure. The stainless steel might discolor when heated (i.e. along the welds, iron impurities, mixed iron crystals). The products made of stainless steel are not passivated.

Stainless Steel V2A

V2A refers to the below mentioned quality or a comparable stainless steel within the same category.

Material Nr. 1,4301 / X 5 CrNi 18-10 (DIN EN 10 088-2, USA: ASTM 304).
Standard : matt surface 2B (ex III C).
Special upon request: shiny surface 2R (ex III D).

Maximum Operating Temp.: 300°C (temporarily: 450°C).
Data also depend on the gasket and the flow medium.
Applications: Food and pharmaceutical industries, chemical equipment.
V2A is not suitable for swimming pool applications, as this material does not resist to chloride concentrations above 150-200 mg/l.

Stainless Steel V4A

Standard: V4A usually refers to the stainless steel 1.4404 (ASTM 316L).
Alternatives: grade1.4571 (ASTM 316Ti) or a comparable quality within the same category.

Maximum Operating Temp.: 300°C (temporarily:450°C).
Data also depend on the gasket and the flow medium.
Applications : Higher resistance against corrosion.

Access Doors in Stainless Steel V2A and V4A

The springs, screws, bolts and the metal knobs for the high temperature versions are made of stainless steel V2A.

Assembly Instructions for Products made of Stainless Steel

Stainless steels are harder and more difficult to machine. That creates a rough surface which, in conjunction with the chromium oxide layer, increases the friction dramatically. Unless a suitable lubricant is used, the bolts and nuts are seized : we cannot further tighten and even untighten them. They are as welded. A lubricating, anti-seize compound for stainless steel parts (i.e. TECCEM AHT415) should be used on stainless steel nuts and bolts. The tightening should be carried out carefully and by hand. Common oil and grease are rarely enough and seizure still takes place.

Work Safety

Please be aware that the edges of products made of stainless steel can be much sharper than the ones made of galvanized steel. We therefore recommend to always use protective gloves when handling our products.

Protective Foil

The stainless steel material comes with a self-adhesive protective foil, which also facilitates its processing. Foil residues are unavoidable and do not constitute a reason for a claim.

The above picture shows an example of METU-FORM ducts made of stainless steel (V2A) with a matt finish. Marks on the surfaces are not excluded and are linked to the manufacturing processes and cannot be avoided. Complaints about the appearance of the products are therefore excluded.