Steel

Labor

  • Labor (Arumukha) - 30 / sqft
  • MS grill with materials and installation - ~ 450/sqft
  • Highly finished door (hollow?) steel - Rs 700/sqft (IndiaMart) - Rs 14.7k.

Mild steel (MS)

  • Aka Carbon steel
  • rusts when exposed to air and moisture. This iron oxide film is active and accelerates corrosion by forming more iron oxide.
  • stiff and strong
  • exhibit ferromagnetism (i.e. they are magnetic). This means they are extensively used in motors and electrical appliances.
  • Welding: Welding carbon steels with a carbon content greater than 0.3 % requires that special precautions be taken. However, welding carbon steel presents far fewer problems than welding stainless steels.
  • no more than 2 % carbon and no other appreciable alloying element.

Cost

  • Sold in “lengths” of 6m or 19.6ft
  • Price fluctuates daily based on steel price.
  • 72mm x 72mm (2.8" x 2.8") rectangular pipe - 5100 Rs per length
  • 80mm x 40mm (3.14" x 1.5") rectangular pipe - 2000 Rs per length
  • 50mm x 50 mm (~2" x 2") rectangular pipe - 1700 Rs per length
  • 25mm x 25mm (~1" x 1") rectangular pipe - 669 Rs per length

Stainless steel

  • Corrodes and stains less, but not stain-proof.
  • 12% + Chromium added for corrossion resistance.
  • very expensive. Hence items are often made hollow.
  • 202 grade
  • 304 grade - 8% nickel and 18% chromium, making it ultra resistant to corrosion and oxidation.
  • 316 grade - higher corrosion resistence.

Cast Iron

  • 2% carbon. Brittle.

  • Most cast iron plumbing systems had at least one leak within 20 years of installation

Galvanized Iron

  • Galvanized steel has zinc layer on the surface level, which when there is scratch, it tends to corrode.
  • GI pipes - zinc layer may leach lead.

GI sheet cost 2021

  • Market dominated by u3s in sahakAranagara bengaLUru.
  • 1mm 8x4 - 6000 or 166 / sqft
  • 2mm 8x4 - 9360

Ribbed sheets

  • Aka profile Sheets.
  • Has ribs every few inches apart. Sheets are joined with screws in these raised parts - reduces water leakage.
  • Tata Durashine sheet (47mm?) thick
    • Layers - Color, Zn-Al, Core steel, Zn-Al, Color
    • Better standards - thickness, shaping to reduce leaks at joints.
    • Reduces temperature by 5 degrees - relative to plain sheet?
    • Also comes in tile widths - 3.2ft.