How Are Torqueing Specs Determined

I was speaking of lock washers, not regular washers but it's all good

 

That's OK, but not all lock washers are 'split' washers.. bellville, cone/spring, wave, serrated etc... and the various materials of each too...

Heck we haven't even covered pinch nuts!

Most all engineers know this but this is for the laymen out there reading this, bolts are in reality 'springs' a bolt that no longer stretches will break, so it has to stretch and relax just a bit or cycle. This is also why fasteners in some industries have a life cycle... As an old mentor told me one day "****s always moving"

A washer isn't going to alter the stretch of the bolt though as that's a function of the bolt itself. The washer will work in conjunction with the clamp load and is used when there are differing diameters or materials being clamped and 'lock' washers are also used to resist vibration loosening. It's very application specific though.

 

What I always find amusing is the misuse of washers(non locking). Say you have a block of steel and a .280 hole for a 1/4-20 bolt. Many seem to think washers are always needed and will add a washer with the same ID which in this example does nothing but waste the washer and add increased length to the bolt

 

Very true.

This can be a fun little challenge though, what about the surface finish of steel and the operating environment? Serviceability, will the joint be fixed for it's life duration or does it require periodic removal and checking?

 

Sure - if the purpose is to protect the base part from getting all chewed up that it's a good idea but I've just seen it so many times were it is not required

 

It's not the size of the bolt it's the friction!

 

I agree, I was just having a bit of geeky fun..