14 CFR § 31.37 - Fastenings.

---
identifier: "/us/cfr/t14/s31.37"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 31.37 - Fastenings."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "31.37"
section_name: "Fastenings."
chapter_name: "FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "AIRCRAFT"
part_number: "31"
part_name: "AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 106(g), 40113, 44701-44702, 44704."
regulatory_source: "Docket No. 1437, 29 FR 8258, July 1, 1964, as amended by Amdt. 31-1, 29 FR 14563, Oct. 24, 1964, unless otherwise noted."
cfr_part: "31"
---


# 31.37 Fastenings.

Only approved bolts, pins, screws, and rivets may be used in the structure. Approved locking devices or methods must be used for all these bolts, pins, and screws, unless the installation is shown to be free from vibration. Self-locking nuts may not be used on bolts that are subject to rotation in service.