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Sheet metal · U.S. Standard Gauge · USG

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

000 gauge U.S. Standard sheet is 0.3750 in thick — 9.525 mm. A square foot weighs 15.00 lb (73.24 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
000 ga
Material
U.S. Standard Gauge
Inch
0.3750
mm
9.525
System
USG

000 Gauge U.S. Standard · nominal thickness

0.3750 in

Millimetre
9.525mm
Weight
15.00lb/ft²
Weight
73.24kg/m²

Nominal thickness on the USG system. Gauge numbers are material-specific — "000 gauge" on its own does not name a thickness.

000 Gauge U.S. Standard Sheet Thickness

000 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.

000 Gauge U.S. Standard — thickness and weight
PropertyValue
Thickness, decimal inch0.3750 in
Thickness, millimetre9.525 mm
Weight per square foot15.00 lb/ft²
Weight per square metre73.24 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 000 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 000 gauge
PropertyThickness
Gaugeinmm
00000 ga0.437511.113
0000 ga0.406310.319
000 ga0.37509.525
00 ga0.34388.731
0 ga0.31257.938

Sources and Method for 000 Gauge U.S. Standard Thickness

000 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

  0.3750 × 41.82  =  15.00 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 000 Gauge U.S. Standard Reference

Citation

ShopMath. "000 Gauge U.S. Standard Thickness in Inches and Millimetres." ShopMath, verified August 1, 2026, https://shopmath.org/gauges/us-standard/000

BibTeX

@misc{shopmath-gauges-us-standard-000,
  title        = {000 Gauge U.S. Standard Thickness in Inches and Millimetres},
  author       = {{ShopMath}},
  year         = {2026},
  howpublished = {\url{https://shopmath.org/gauges/us-standard/000}},
  note         = {Data verified 2026-08-01}
}

Permanent URL

https://shopmath.org/gauges/us-standard/000

Common Questions About 000 Gauge U.S. Standard

How thick is 000 gauge U.S. Standard?

000 gauge U.S. Standard is 0.3750 in thick, which is 9.525 mm. A square foot weighs 15.00 lb (73.24 kg/m²).

What is 000 gauge U.S. Standard in mm?

9.525 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.

Is 000 gauge U.S. Standard thicker than 0000 gauge?

No — a lower gauge number is thicker sheet. 0000 gauge us standard is 0.4063 in (10.319 mm) against 0.3750 in (9.525 mm) for 000 gauge U.S. Standard, a difference of 0.0313 in.

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