The list below is a running data base of the gap from mouthpieces that have passed through the shop (data collection began on 7/1/2015). The measurements were taken with a gap check tool, where the shank of the mouthpiece is inserted into the tool. If the shank is flush with the end of the tool, then the shank end diameter is 0.385". A change in diameter of 0.001" will change the insertion or gap by 0.020". A mouthpiece with a 0.384" shank end diameter will insert -0.020" into the tool, a mouthpiece with a 0.386" shank end diameter will insert +0.020" into the tool, etc. The purpose of this list is to track the industry standards and to illustrate the need for Frost Threaded Sleeves to accurately control gap. Updated 12/22/2017.
