---
kind: "section"
citation: "49 C.F.R. § 179.100-10"
title: "49"
number: "179.100-10"
heading: "Postweld heat treatment."
url: "https://uscodex.org/cfr/49/179.100-10"
---

# §179.100-10. Postweld heat treatment.

- (a) After welding is complete, steel tanks and all attachments welded thereto must be postweld heat treated as a unit in compliance with the requirements of AAR Specifications for Tank Cars, appendix W (IBR, see [§ 171.7](/cfr/49/171.7.md) of this subchapter).
- (b) **For aluminum tanks, postweld heat treatment is prohibited.**
- (c) Tank and welded attachments, fabricated from ASTM A 240/A 240M (IBR, see [§ 171.7](/cfr/49/171.7.md) of this subchapter), Type 304L or Type 316L materials do not require postweld heat treatment, but these materials do require a corrosion resistance test as specified in [§ 179.100-7(c)(2)](/cfr/49/179.100-7.md?p=c-2).

## Notes

### Amendments

[Amdt. 179-10, 36 FR 21345, Nov. 6, 1971, as amended by Amdt. 179-47, 58 FR 50238, Sept. 24, 1993; Amdt. 179-52, 61 FR 28679, June 5, 1996; 67 FR 51660, Aug. 8, 2002; 68 FR 75758, 75759, Dec. 31, 2003]

### Authority

Authority: 49 U.S.C. 5101-5128; 49 CFR 1.81 and 1.97.

### Source

Source: 29 FR 18995, Dec. 29, 1964, unless otherwise noted. Redesignated at 32 FR 5606, Apr. 5, 1967.

### Amendments

[Amdt. 179-10, 36 FR 21345, Nov. 6, 1971, as amended by Amdt. 179-47, 58 FR 50238, Sept. 24, 1993; Amdt. 179-52, 61 FR 28679, June 5, 1996; 67 FR 51660, Aug. 8, 2002; 68 FR 75758, 75759, Dec. 31, 2003]