HDG Calculators
Free hot-dip galvanizing calculators built from real plant data — no sign-up needed. The full versions, with exports and every option, are in the members area.
Steel Reactivity Checker
Will this steel galvanize well? Enter Si, P, Al off the mill certificate — Sandelin & Sebisty ranges, appearance, and advice.
Open the checker → FreeZinc Coating Unit Converter
µm ↔ g/m² ↔ mils ↔ oz/ft², synchronized live — ISO 1461 Annex D density basis with a pure-zinc toggle.
Open the converter → FreeDuplex Life Estimator
Galvanizing plus paint outlasts the sum of both. Enter zinc thickness, environment and paint life — see the range.
Open the estimator → FreeCoating Thickness Finder
The coating thickness your spec actually requires — ASTM A123 & ISO 1461 side by side, local vs mean included.
Open the finder → FreeInspection Sampling Planner
How many articles must you test for this lot, and how many measurements on each? ASTM A123 cl. 7.3 & ISO 1461 Table 1.
Open the planner → FreeGalvanizing Lifetime Estimator
Years to first maintenance from coating thickness and ISO corrosivity category C1–CX, per ISO 14713-1.
Open the estimator → FreeGalvanizing Cost Calculator
Estimate galvanizing cost per tonne of steel from thickness and zinc price — zinc consumption, process cost and margin.
Open the calculator → FreeZinc Consumption Calculator
Estimate kg of zinc consumed per tonne of steel — coating plus dross and ash. The biggest variable in galvanizing cost.
Open the calculator → FreeVent & Drain Hole Calculator
Size vent/drain holes for hollow sections (CHS, SHS, RHS) before the kettle — so air vents and zinc drains.
Open the calculator → FreeSteel Weight Calculator
Profile weights & standard sections (IS 808, EN, BS, JIS) — weight per metre and per piece. Full version adds grating, wire & reference.
Open the calculator → FreeRepair & Renovation Allowance Checker
Repair the bare spot or re-galvanize? Uncoated-area limits and repair thickness under ASTM A123-24, A780 and ISO 1461:2022.
Open the checker → FreeSpecification Clause Builder
Copy a coating clause into your order: standard, sample, gauge, referee, repair limits and inspection — ASTM A123 or ISO 1461.
Open the builder → FreeKettle Envelope & Double-Dip Checker
Will it fit the kettle? Working dimensions, hot length, tilted fit, progressive dipping and the distortion risk.
Open the checker → FreeFlux Bath Optimizer
Salt in g/L, iron, temperature and pH for a zinc ammonium chloride flux — the additions, the dross your flux iron makes, and the peroxide to clear it.
Open the optimizer → FreeZinc Reconciliation Scorecard
One month of plant numbers: level-corrected consumption, dross and ash against the ceilings, net zinc cost and the cost of excess microns.
Open the scorecard → FreeFastener Overtapping & Embrittlement Checker
How far to tap a galvanized nut oversize (ISO 10684, ASTM A563), the bolt's coating class (A153), and the hydrogen precautions for its strength (A143).
Open the checker →Planning a new plant?
HDG Plant Design sizes a complete galvanizing plant from your output target: kettle, chemical line, building and cranes, with a first capital-cost estimate. It runs on its own site, free and with no sign-up.
Open HDG Plant Design →The full tool suite
Plant design, service cost, steel products, pickling optimizer, HCl converter and the vent & drain hole planner — with PDF/drawing exports and every option unlocked.
See membership — $149/yr