Norms and Tolerances

1. Sheets and coils:
2. chemical composition according to EN 10088-2,
3. tolerances for hot-rolled sheets, plates and coils EN 10029,
4. tolerances for cold-rolled sheets, plates and coils EN 10259,
5. tolerances for cold-rolled narrow strips ISO 9445,
6. surface quality and other EN 10028-7
7. BA/2R surface minimum gloss 700GU

• Tolerances and rules for sheets, plates and coils
• for orders for custom-cut width and length, tolerances are -0,00 / +5mm
• for orders for polished or foiled coils, the standard is that the first 5 metres and the last 14 metres are with no foil or polishing.
• for sheet and plate orders with paper spacer only, the Seller does not guarantee surface free of scratches
• Side B of the material may have scratches: the Seller never guarantees the other side,
• for orders for polished sheet, plate and coils , the standard is:

–  partly polished edges up to 15 mm from each side of the sheet / plate,

– foil protruding off the outline of the sheet / plate.

• Profiles, pipes, flat bars
• chemical composition according to EN 10088-2
• standard of execution for welded profiles EN 10219-2 i/lub ASTM A554,
• standard of execution for welded pipes for structural and decorative use  EN 10296-2 i/lub ASTM A554,
• standard of execution for welded pipes for industrial installations EN 10217-7,
• standard of execution for welded pipes for the food industry EN 10357 (this standard replaced DIN 11850),
• dimensions, tolerances and calculated mass for stainless steel pipes ISO 1127
• tolerances for cut flat bars EN10028-7/EN10088-2/EN10088-4, DIN1017
• the standard is that polished materials may have thickness off the standard parameters due to the machining technology, and the first and last 10 cm up to 80% less than the assumed thickness of the material.

• Angle sections and rods
• chemical composition according to EN 10088-3,
• tolerances for angle sections DIN 1028,
• tolerances for cold-finished round rods EN 10278,
• tolerances for hot-finished round rods EN 10060,
• tolerances for hot-finished square rods EN 10059
• the standard is that polished materials may have thickness off the standard parameters due to the machining technology, and the first and last 10 cm up to 80% less than the assumed thickness of the material.

Protect stainless steel from rust using proven cleaning methods

Stainless steels are highly corrosion resistant—however, stainless steel applications can still remain at risk to surface damage. Oxidation, corrosion, rusting, or staining can occur over the long-term in harsh environments without routine cleaning and maintenance. Repeat mechanical damage also contributes to a faster degradation of the metal.

All stainless steels contain at least 10.5% chromium by weight. It is this chromium content that creates a shield called the passive layer, which protects stainless steel from corrosion—unlike other steels. The higher the chromium content, the greater the corrosion resistance. Stainless steel rusting occurs when the passive layer is damaged and there is not enough chromium for it to reform.

How does the passive layer work?

The passive layer is created as the chromium content in the stainless steel’s surface reacts to oxygen. The passive layer acts as a protective barrier, preventing further oxidation of the stainless steel. In comparison, ordinary carbon steel surfaces form ferric oxide when exposed to oxygen. Ferric oxide does not form a continuous layer, so it eventually spalls off, leaving raw steel exposed and prone to a destructive rusting cycle.

The passive layer of stainless steel is self-repairing. If it is damaged, chromium in the exposed stainless steel will react with oxygen to form new chromium oxide. As long as there is sufficient chromium present, the chromium oxide layer will continue to reform and protect the stainless steel surface.

Causes of stainless steel corrosion

Chromium can protect stainless steel if the localized concentration is 12% or higher. Anything reducing the localized chromium concentration below the 12% threshold will cause staining or rust. Common causes of stainless steel corrosion include chlorides, hydrochloric acids, sulfuric acids, iron or carbon steel contact, and high temperatures. There are over 150 grades of stainless steel, and some are more prone to corrosion than others. The corrosion resistance and other useful properties of stainless steel are enhanced by increasing the chromium content, or by the addition of other elements such as molybdenum, nickel, and nitrogen.

Handling stainless steel

The service life of stainless steel can be extended by preventing contact with corrosive substances. Follow best practices when working with stainless steel:

• Always wear clean gloves.
• Always use stainless steel tools and components.
• Avoid any contact with carbon steels or iron.
• Do not weld, cut, drill, or grind carbon steel near stainless steel.
• Avoid contact with concrete detergents.
• Avoid contact with chloride solutions.
• Do not use steel wool or other abrasive scrubbing pads.

The most common mistake people make is using a corrosive product to clean stainless steel surfaces. Never use the following products on stainless steel:

• Chloride cleaners
• Abrasive cleaners
• All-purpose cleaners
• Chloride bleach

Routine stainless steel cleaning

Stainless steel must be cleaned regularly to preserve the metal’s integrity and maintain a pristine appearance. With proper care, and by selecting an appropriate grade, stainless steel can be saved from corrosion. When stainless steel maintenance is neglected, corrosive substances can accumulate on vulnerable surfaces.

Routine cleaning steps (perform every 6 months)

1. Use a soft nylon brush to remove accumulated dirt.
2. Wash with mild soap or detergent.
3. Follow with a clean-water rinse.
4. Wipe dry with a soft cloth, disposable wipe, or air blower.

Stainless steel care and maintenance may require the use of harmful chemicals. Follow all safety instructions provided with cleaning or polishing agents. Ensure personal protective equipment is worn in accordance with occupational health and safety guidelines.

Specific stainless steel cleaning

When stainless steel has become extremely dirty with signs of surface discoloration or corrosion, routine cleaning may no longer suffice. Cleaning methods designed to tackle specific types of damage are listed below.

·        Fingerprints

• Clean with soap or detergent and warm water.
  • Commercially-available solutions or hydrocarbon solvents can also be used.

·        Oil and grease marks

• Use isopropyl alcohol, acetone, or methylated spirit.
  • Apply solvent several times with a clean, non-scratching cloth until all marks are removed.

·        Localized rust stains

• Use a soft cloth to apply an oxalic acid solution.
  • Leave the solution on the surface for a few minutes to dissolve contaminating particles.
  • Rinse away all residual solution with clean water.

Cyt. Za:  https://www.reliance-foundry.com/blog/cleaning-stainless-steel#gref