The ends of the boiler plate are roughly machined to taper out to a knife edge along the foundation ring. this is to allow the side plate to sit on the outside face without a step from the inner plate stopping.
The ends of the boiler plate are roughly machined to taper out to a knife edge along the foundation ring. this is to allow the side plate to sit on the outside face without a step from the inner plate stopping.
Credit: L.Thorp, 7th Dec 2008