The difference between winning and losing a fabrication tender often comes
down to one thing: the accuracy and professionalism of your quotation.
Underquote, and you lose margin. Overquote, and you lose the job. This guide
walks through the key components of an accurate steel tank estimate.
WHY MOST ESTIMATES ARE WRONG:
The three most common estimation mistakes in tank fabrication are:
1. Forgetting consumables — welding wire, shielding gas, cutting discs,
and abrasives are often missed entirely or grossly underestimated.
2. Undercosting labour — fabrication shops typically estimate cutting and
forming time accurately but forget contingency hours for rework,
re-fitting, and quality checks.
3. Missing testing costs — pneumatic leak testing, DFT paint thickness
checks, and lifting load tests all consume time and consumables that
must be factored into the quote.
THE COMPLETE COST BREAKDOWN FOR A STEEL STORAGE TANK:
MATERIAL COSTS:
- MS Sheet (shell, roof, base) — priced per kg based on certified
ASTM A36 / S275JR plate
- Structural beams and base frame — SHS/RHS sections
- Fittings — sockets, ball valves, mushroom vents, emergency vents,
camlock adapters, level gauges
- Manhole assembly — gasket, fasteners (M18 Grade 8.8)
- Lifting eyes and ladder
- Name plate and safety stickers
FABRICATION CONSUMABLES:
- MIG wire rolls + shielding gas
- Cutting and grinding discs
- Welding contingency (minimum 15% buffer recommended)
PAINTING MATERIALS:
- Two-coat Epoxy Primer — budget per litre coverage rate
- PU Top Coat — White RAL 9010
- Thinners and abrasive paper
MANPOWER COSTS (per process):
- Cutting — laser or manual, costed per metre of cut
- Forming/bending — costed per sheet
- Fabrication welding — costed per metre of weld path
- Assembly — manhole, fittings, ladder
- Painting — cleaning, priming, top coating
- Always add 15-20% contingency across all labour categories
OVERHEAD ADDITIONS:
- VAT 5%
- Transportation, facility and storage — typically 5%
- Design, admin and warranty — typically 5%
GRAND TOTAL FORMULA:
Total Material Cost + Total Manpower Cost + Overheads =
Your Minimum Viable Quote
Add your profit margin (typically 15-25% for fabrication work) on top
of this figure to arrive at your final quoted price.
THE PROFESSIONAL ADVANTAGE:
Corporate clients and government tenders judge suppliers not just on
price but on the professionalism of the quotation itself. A structured,
itemised Bill of Materials submitted alongside your quote signals
competence and builds confidence before the job even starts.
Our Industrial Storage Tank Estimation Tool & Bill of Materials
spreadsheet handles all of the above automatically — enter your
quantities and rates, and the total calculates instantly.
Download it and submit your next quote in hours, not days.