Steel · 5 thicknesses

G90 Galvanized Steel

G90 HDG · ASTM A653 G90

Hot-dip galvanized with a 0.9 oz/ft² zinc coating. Outdoor-grade corrosion resistance straight off the laser — HVAC, ductwork, and exterior brackets.

Representative steel parts

Thickness & specs

Pick a thickness. Every number below is for that exact gauge.
TRUMPF air bend, this gauge
Bend deduction at standard angles inches
Notes, fine print and guides for this gauge ↓
Design rules, this gauge
How we cut it, notes and guides ↓
Self-clinching hardware, this gauge
Countersinking, this gauge
Tap & clearance drill chart, this gauge
Hardware fit, notes and guides ↓
Deburring, Weber 1350 through-feed
Finishing this material, notes and guides ↓

Working with G90 Galvanized Steel

Notes for the selected gauge
Values marked † are derived from our V-die geometry (die contact width) rather than measured on the brake: hole/cutout distance = the die contact region from the bend line; Z-bend spacing = minimum flange + material thickness + inside radius (45° offsets add the die lean-over). The ACB Laser minimum leg applies when optical angle measurement is required on your bend. Shorter flanges bend fine, measured with standard methods. All bend data is air-bend reference in inches. We verify on a test bend before production runs.
Corner relief is part-specific. Open Corner relief for recommendations and PDF example photos for the selected gauge. Seam gap, relief-opening size and distance from a bend line are separate dimensions; confirm the flat pattern and forming sequence.
Hardware hole sizes and part numbers are our own catalog figures. Hole sizes differ between PEM series, so don't cross them with another shop's chart. The mounting hole tolerance the clinch depends on is ±0.002″. Countersink fits require at least 0.010″ of material land under the cone; anything less leaves a knife edge that burrs and never seats square. Tap drills shown are the standard shop pick (75% thread inch, D−pitch metric); dial the percentage to your material on the tap & clearance drill chart.

Material properties

Reference values for the alloy family

Compare grades in the metal density chart when estimating weight. For strength specifications, read yield strength vs tensile strength before choosing a design value.

Mechanical & physical

Reference values per the listed specification. A basis for design comparison, not guaranteed minimums for certification work. Material certs available on request.

Supported services

G90 Galvanized Steel bend data by thickness

K-factor, inside radius and bend deduction for a 90° air bend
Every gauge in one table · 5 thicknesses
G90 Galvanized Steel K-factor, inside bend radius, V-die, bend deduction and bend allowance by thickness
ThicknessGaugeV-dieInside radiusK-factorBD 90°BA 90°Min. flange
0.024″ 0.61 mm24 ga8 mm0.050″0.380.0552″0.0929″0.198″
0.036″ 0.91 mm20 ga8 mm0.050″0.380.0721″0.1000″0.198″
0.048″ 1.22 mm18 ga8 mm0.050″0.380.0887″0.1072″0.198″
0.060″ 1.52 mm16 ga12 mm0.076″0.360.1185″0.1533″0.298″
0.135″ 3.43 mm10 ga30 mm0.189″0.400.2663″0.3817″0.744″

Values come from our TRUMPF tooling tables for the die and punch that run each thickness. Bend allowance is calculated as π/2 × (R + K × T). Select a thickness above for every bend angle and the forming limits. How the K-factor works, and every material compared → K-factor chart for G90 Galvanized Steel →

Feature chart

Scored 1–5 against the other alloys we stock
Material composition — chemistry, temper and what they change

Material science / educational reference

Material composition

G90 describes the amount of zinc coating on sheet steel. It is not the chemical grade of the steel substrate.

Inside the material

Expand to explore

Qualitative composition overview. G90 specifies a minimum triple-spot average coating weight of 0.90 oz/ft² total across both sides; this is not 90% zinc.

IronSteel substrate

The bulk of the sheet is steel. Its exact chemistry follows the ordered base-steel designation.

CarbonGrade dependent

A small but influential constituent. Carbon content and thermal history affect the balance of strength, hardness and ductility.

ZincHot-dip surface coating

Zinc provides a barrier and sacrificial corrosion protection. Its coating mass is specified separately from the base steel.

Only selected constituents are shown. Weight percent is mass fraction × 100. “Balance” is the remainder after all other elements; ranges and maximum limits are not amounts to add together.

Industry references & further reading

Sources explain the reference basis; they do not certify the material supplied. Reviewed September 19, 2026.

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