A plain gasket which can be fabricated in any required configuration. With adequate bolting, #340 is effective and economical, especially on flanges with concentric serrations. In addition to exceptional mechanical strength, other characteristics of #340 include heat conductivity and excellent resistance to high pressures, high temperatures and chemical attack. If gasket is not finished machined, minimum width should be 50% more than the thickness of the metal. The only limitation on dimensions of the flat metal gasket is the width of metal sheet commercially available.

Offers the desirable characteristics of the solid gasket plus the advantage of reduced contact area supplied by V-shaped rib surface. #341 is used where a solid gasket is required due to pressure, temperature or the intensely corrosive effect of the confined fluid, and bolting would not be adequate to seal the #340 gasket. Another applications of #341 is in the case of screwed, or attrition, closures in which the relatively small contact area reduces friction to a level sufficiently low to seal the joint.