Fastener Guide / Engineering & Failure Analysis

Vibration Loosening

Bolts self-loosen when the joint slips sideways under vibration, letting the nut rotate backwards. Maintaining preload is the main defense.

Last reviewed 2026-09-10 · Governing standard: DIN 65151; ISO 16130 · reference FG-D98384 · Report an error on this sheet

Loosening at a glance

MechanismTransverse slip releases thread friction and the nut backs off
TestJunker transverse vibration test (DIN 65151 / ISO 16130)
Best defensesAdequate preload, longer bolts, wedge-lock washers, threadlocker, prevailing-torque nuts
Weak defenseSplit lock washers provide little resistance

Governing standards: DIN 65151; ISO 16130. Editions shown are the latest confirmed as of September 2026. The drawing and the governing standard always take precedence over this sheet.

These tables carry the same figures as the printed sheet below.

The printed sheet

Vibration Loosening

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Text version of this sheet

Vibration loosening

What it is

FAILURE MODE

Bolts self-loosen when the joint slips sideways under vibration, letting the nut rotate backwards.

Maintaining preload is the main defense.

Transverse vibration self-loosens nuts

Loosening at a glance

Mechanism

Transverse slip releases thread friction and the nut backs off

Test

Junker transverse vibration test (DIN 65151 / ISO 16130)

Best defenses

Adequate preload, longer bolts, wedge-lock washers, threadlocker, prevailing-torque nuts

Weak defense

Split lock washers provide little resistance

Governing standards: DIN 65151; ISO 16130. Editions shown are the latest confirmed as of September 2026. The drawing and the governing standard always take precedence over

this sheet.

torquing any fastener. Verify the current governing standard, project documents, OEM requirements, size, thread, coating and lot certification. To the fullest extent permitted by law, The Fastener App disclaims liability

arising from reliance on this reference.

Fastener Guide reference FG-D98384 · thefastenerapp.com/fastener-guide/failure-analysis/vibration-loosening · © The Fastener App. Reference only — verify the current governing standard, drawing and manufacturer data before specifying or installing.

Related sheets

← Torque / Preload FailureHydrogen Embrittlement Failure →

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