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Sheet metal · U.S. Standard Gauge · USG

0000000 Gauge U.S. Standard Thickness in Inches and Millimetres

0000000 gauge U.S. Standard sheet is 0.5000 in thick — 12.700 mm. A square foot weighs 20.00 lb (97.65 kg/m²). The gauge number indexes the USG system, so the same number is a different thickness in another material — the comparison is below. Thicknesses are nominal, before mill tolerance.

Gauge
0000000 ga
Material
U.S. Standard Gauge
Inch
0.5000
mm
12.700
System
USG

0000000 Gauge U.S. Standard · nominal thickness

0.5000 in

Millimetre
12.700mm
Weight
20.00lb/ft²
Weight
97.65kg/m²

Nominal thickness on the USG system. Gauge numbers are material-specific — "0000000 gauge" on its own does not name a thickness.

0000000 Gauge U.S. Standard Sheet Thickness

0000000 Gauge U.S. Standard is defined by the 15 U.S.C. 206 (wrought iron basis), not by a measurement — the gauge number is an index into that system, which is why the same number means a different thickness in another material.

0000000 Gauge U.S. Standard — thickness and weight
PropertyValue
Thickness, decimal inch0.5000 in
Thickness, millimetre12.700 mm
Weight per square foot20.00 lb/ft²
Weight per square metre97.65 kg/m²
Gauge systemUSG

Nominal thickness. Mill tolerance on sheet is typically a few thousandths of an inch either way and varies with width and process; measure the stock when the fit matters.

Gauges Either Side of 0000000 Gauge U.S. Standard

A higher gauge number is thinner sheet. The steps are not equal — the gauge systems are geometric, so the difference between two gauges shrinks as the sheet gets thinner.

U.S. Standard Gauge gauges adjacent to 0000000 gauge
PropertyThickness
Gaugeinmm
0000000 ga0.500012.700
000000 ga0.468811.906
00000 ga0.437511.113

Sources and Method for 0000000 Gauge U.S. Standard Thickness

0000000 Gauge U.S. Standard thicknesscomputed

15 U.S.C. 206 (Act of Mar. 3, 1893, ch. 221, 27 Stat. 746) — U.S. Standard Gauge for sheet and plate iron and steel; 15 U.S.C. 206 statutory weights; MSG (41.82 lb/ft2 per inch), galvanized zinc allowance, and Brown & Sharpe formula per docs/research/data-sourcing.md §3.7

Verified against Wikipedia Sheet metal, Standard sheet metal gauges table (CC BY-SA 4.0) — 137/137 checks passed at 0.05 mil

Computed from the standard's formulas, then checked against published tables.

Formula

Weight per square foot, sheet steel

lb/ft²  =  thickness (in) × 41.82

  0.5000 × 41.82  =  20.00 lb/ft²

41.82 lb/ft² per inch of thickness is the Manufacturers' Standard Gauge basis for steel. The U.S. Standard Gauge of 1893 uses a wrought-iron basis of 40 lb/ft² per inch, which is why the two systems differ.

Assumptions
  • Thicknesses are nominal. Mill tolerance varies with width, process and material and is not part of the gauge definition.
  • Gauge is an index into a material-specific system, not a unit. A gauge number without a material is ambiguous by construction.
  • Dataset scope: EXCLUDED: stainless steel (genuinely ambiguous convention, only one source in hand), zinc, copper, brass, steel tube wall.
Data last verified
August 1, 2026
How this data is built and checked →

How to Cite This 0000000 Gauge U.S. Standard Reference

Citation

ShopMath. "0000000 Gauge U.S. Standard Thickness in Inches and Millimetres." ShopMath, verified August 1, 2026, https://shopmath.org/gauges/us-standard/0000000

BibTeX

@misc{shopmath-gauges-us-standard-0000000,
  title        = {0000000 Gauge U.S. Standard Thickness in Inches and Millimetres},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/gauges/us-standard/0000000}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/gauges/us-standard/0000000

Common Questions About 0000000 Gauge U.S. Standard

How thick is 0000000 gauge U.S. Standard?

0000000 gauge U.S. Standard is 0.5000 in thick, which is 12.700 mm. A square foot weighs 20.00 lb (97.65 kg/m²).

What is 0000000 gauge U.S. Standard in mm?

12.700 mm. The gauge number is an index into the USG system rather than a measurement, so it converts to a fixed thickness rather than a round metric figure.

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