---
kind: "section"
citation: "49 C.F.R. § 230.24"
title: "49"
number: "230.24"
heading: "Maximum allowable stress."
url: "https://uscodex.org/cfr/49/230.24"
---

# §230.24. Maximum allowable stress.

- (a) **Maximum allowable stress value.** The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate tensile strength of its material.
- (b) **Safety factor.** When it is necessary to use the code of original construction in boiler calculations, the safety factor value shall not be less than 4.

## Notes

### Authority

Authority: 49 U.S.C. 20103, 20107, 20702; 28 U.S.C. 2461 note; and 49 CFR 1.89.

### Source

Source: 64 FR 62865, Nov. 17, 1999, unless otherwise noted.