# -4 Thickness of plates.

- **operation:** document
- **citation:** 49 CFR 179.202-4
- **title:** -4 Thickness of plates.
- **source type:** regulation
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** current
- **official:** true
- **published on:** Not available
- **effective on:** 2026-08-18
- **summary:** The wall thickness after the forming of the tank shell and heads must be, at a minimum, 9/16 of an inch AAR TC-128 Grade B, normalized steel, in accordance with § 179.200-7(b).

[80 FR 26749, May 8, 2015]
- **machine formats:** - **json:** https://regulus.evalyn.ai/document/49-cfr-179-202-4.json
- **markdown:** https://regulus.evalyn.ai/document/49-cfr-179-202-4.md
- **app url:** https://regulus.evalyn.ai/document/49-cfr-179-202-4
- **source url:** https://www.ecfr.gov/on/2026-08-18/title-49/section-179.202-4
**body:**

The wall thickness after the forming of the tank shell and heads must be, at a minimum, 9/16 of an inch AAR TC-128 Grade B, normalized steel, in accordance with § 179.200-7(b).

[80 FR 26749, May 8, 2015]
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- **body characters:** 204