U.S. statutory iron / steel gauge
Sheet Gauge and Thickness
Gauge is a named lookup system, not a length unit. This table transcribes selected approximate thicknesses from the historical U.S. statutory iron-and-steel gauge in 15 U.S.C. § 206. It is not MSG, stainless sheet gauge, or aluminum gauge.
Content reviewed 2026-11-02. Verify the applicability of each source before using a value in a quote.
Input to record
Identify the gauge system and material before using a number. For purchasing and CAM, use the decimal thickness stated by the drawing or supplier.
Output to carry forward
An approximate nominal thickness for the explicitly named gauge system, followed by a decimal mm or inch value confirmed for the actual stock.
System check
| Label on order | Action | Do not assume |
|---|---|---|
| U.S. statutory iron/steel gauge | Use this table only when that system is explicitly intended. | Do not treat the historical statutory values as current supplier MSG stock sizes. |
| Manufacturers’ Standard Gauge / MSG | Use the supplier’s steel gauge chart and quoted decimal thickness. | Do not substitute values from 15 U.S.C. § 206. |
| Stainless steel gauge | Ask for the stainless chart and actual ordered thickness. | The same gauge number need not match carbon steel. |
| Aluminum gauge / Brown & Sharpe | Confirm the named chart or order directly in mm/in. | Do not copy iron/steel gauge thickness into aluminum CAM. |
Decimal conversion
Once the actual thickness is known, convert inches to mm by multiplying by 25.4; convert mm to inches by dividing by 25.4. For example, 0.0625 in × 25.4 = 1.5875 mm. Gauge-to-mm requires a named table first; it cannot be calculated from the gauge number alone.
A nominal conversion does not define stock thickness tolerance, coating thickness, or measured sheet thickness. Preserve the original supplier designation and the decimal dimension in the quote record.
Sources and scope
Content reviewed 2026-11-02. A documentation reference supports the stated method or data only; it does not approve settings on another machine.
- 15 U.S.C. § 206 — Standard gauge for sheet and plate iron and steel
Historical U.S. statutory gauge. These approximate thicknesses are not Manufacturers’ Standard Gauge (MSG), stainless sheet gauge, or aluminum/Brown & Sharpe gauge.
Showing 11 of 11 rows
| Gauge number | Approximate inches | Approximate mm | System / material scope | Source | Confidence | Reviewed |
|---|---|---|---|---|---|---|
| 8 | 0.171875 | 4.365625 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 10 | 0.140625 | 3.571875 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 12 | 0.109375 | 2.778125 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 14 | 0.078125 | 1.984375 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 16 | 0.0625 | 1.5875 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 18 | 0.05 | 1.27 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 20 | 0.0375 | 0.9525 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 22 | 0.03125 | 0.79375 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 24 | 0.025 | 0.635 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 26 | 0.01875 | 0.47625 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
| 28 | 0.015625 | 0.396875 | U.S. statutory iron/steel gauge (15 U.S.C. § 206) | 15 U.S.C. § 206 table | Verified source transcription; approximate nominal thickness | 2026-11-02 |
Reference workflow
- Match the job, material, machine head, and quality requirement to a row.
- Confirm the source, review date, and confidence before copying the value into a quote worksheet.
- Use a measured result or current OEM record when the row is marked as required or unverified.