Decision inputs
- Stud size and target preload
- Radial and axial clearances
- Temperature and corrosive environment
- Expected gasket/packing consolidation
- Maintenance interval
APPLICATION SOLUTION
Fastener anti-loosening & tensioning
Conical spring washers (DIN 6796) and disc spring live load assemblies maintain bolt preload and compensate consolidation and thermal growth; this page gives selection inputs, assembly patterns and anti-loosening verification methods.
ENGINEERING PROBLEM
Bolted joints lose preload under vibration, thermal cycling and gasket or packing consolidation, leading to leakage or loosening.
BOUNDARY
This page describes a decision pattern and does not promise size or performance for another operating condition.
Solution pattern
- Maintain elastic preload with DIN 6796 conical washers or live load assemblies (disc springs + guides + end washers)
- Bound maximum washer OD and stack height by the clearance envelope
- Control assembly by height or torque-to-load and record it
Key risks
- Wrong washer selection under-compensates preload loss
- High-temperature relaxation reduces long-term retention
- Radial slippage driven self-loosening is not suppressed
Verification plan
- Preload-displacement verification
- Vibration testing (Junker type)
- Residual preload measurement after thermal cycling
- Scheduled re-tightening with records
Source-backed correspondences
| Summary | Load | Travel | Source |
|---|---|---|---|
| 紧固件防松/张紧——按tensioning目标预选产品族；场景摘要仅供决策参考，不构成对其他工况的产品承诺。 | 按预紧力目标 | 防松补偿行程 | Source ↗ |
Evidence (library locators)
Every technical claim traces to a specific asset version and page; restricted sources show locator metadata only.
- Springer Friction 2022 Radial Slippage Self loosening Anti loosening Design PDF p.1 · mechanism(internal source; excerpt not public)
- BoltScience Why Nuts and Bolts Self Loosen PDF p.1 · mechanism(internal source; excerpt not public)
- NordLock Bolted Magazine 1 2019 Torque Preload Friction PDF p.24 · mechanism(internal source; excerpt not public)
- 434 Seal Tech 5150 Live Load Assemblies 数据表 PDF p.1 · mechanism(internal source; excerpt not public)
- 439 Belleville International Flange Live Loading Using Belleville Spring F PDF p.3 · mechanism(internal source; excerpt not public)
- 436 US3077218 Lockwasher in Form of Dish Spring 专利直链 PDF p.2 · mechanism(internal source; excerpt not public)
- 439 Belleville International Flange Live Loading Using Belleville Spring F PDF p.1 · mechanism(internal source; excerpt not public)
- 435 DIN 6796 2009 08 Conical Spring Washers for Bolted Connections 标准正文 PDF p.2 · mechanism(internal source; excerpt not public)
- Springer Friction 2022 Radial Slippage Self loosening Anti loosening Design PDF p.5 · numeric(internal source; excerpt not public)
- Springer Friction 2022 Radial Slippage Self loosening Anti loosening Design PDF p.8 · numeric(internal source; excerpt not public)
- Springer Friction 2022 Radial Slippage Self loosening Anti loosening Design PDF p.8 · numeric(internal source; excerpt not public)
- Springer Friction 2022 Radial Slippage Self loosening Anti loosening Design PDF p.8 · numeric(internal source; excerpt not public)
- Springer Friction 2022 Radial Slippage Self loosening Anti loosening Design PDF p.9 · numeric(internal source; excerpt not public)
- Springer Friction 2022 Radial Slippage Self loosening Anti loosening Design PDF p.10 · numeric(internal source; excerpt not public)
Cases illustrate decisions and do not constitute a specification promise for any other operating condition.
ENGINEERING REVIEW