I assume you mean "cork". As a general rule of thumb 1/16" cork is used for the key feet of the upper and lower stacks of saxophones as well as the palm and side keys. In my experience rarely does the foot cork need to exceed this thickness, however in some instances it is advantageous to add a felt pad on the body of the instrument under this foot cork for silencing or to reduce key bounce.habschi2 said:
When the 1/16" cork doesn't allow enough key opening, it can easily be sanded to adjust. Adjustments for lost motion in the stack keys can also be made by sanding the feet cork.
John
