Washers

Edited By Martin W on 08/12/2009 18:35:47

Edited By meyrick griffith-jones on 13/12/2009 01:00:18

Hi everyone

I am a consultant in the bolting industry, it's my job to design tools, calculate bolting requirements and provide procedures. Provided correct lubrication is applied washers are not used unless there is good reason to protect the surface of the component. On critical applications with high bolt loads thick hardened washers may be used to assist in load distribution and tightening method. Lubricants such as copperslip or coppaslip are termed anti-seize compounds, they lubricate for tightening then give corrosion prevention to assist in loosening. You have to be very careful which compounds you use depending upon bolt materials and operating condition.  Spring washers etc provide no benefit on structural applications, correctly designed and tightened joints don't need any additional feature, or locknuts or anything, There are a couple of exceptions that employ tab washers or heavy duty Belleville washers. On critical joints use anti seize compounds, normal grease and oils increase the torque required and reduce control over bolt load. Don't use molybdenum-based compounds unless you know what you are doing, you could put a critical joint into a dangerous condition.

Nigel

Edited By tractionengine42 on 13/12/2009 03:38:17

Edited By Circlip on 13/12/2009 11:58:09

Edited By Circlip on 13/12/2009 11:59:49