Originally Posted by
tomtomtom123
The old shims were made of bronze but the new ones are stainless steel. However I've used shims that are made up of stacked layers of 0.5 mm sheets that you peel off to reduce the thickness. That's probably weaker than a single homogenous sheet so I'm not sure if it would deform or thin out over time.
I now recall the discussion years ago. Softer alloy is good to take the imperfections. SS might be hard and may mark the frame making the imperfection worse. the reason I went for the 3M stuff is that it compresses and fills the gaps. as it is for automotive hot/cold purpose, it is durable and as it is organic, it does not creak.