King Mouthpiece Identification

[CharlieB]

I have three King M21 mouthpieces.
One is a 12ish piece with no decorative (coin edge) knurling. Bore = 0.227
Another is a 7ish piece with knurling at the rim and at 1 3/4" from the stem end. Bore = 0.227
All pretty standard stuff.

The third mouthpiece is a mystery to me. It has a 12ish rim, a bore of 0.232, and two rows of knurling, with the lower knurling only 1 1/2" from the stem end. I can't find any reference to a King M21 with a 0.232 bore. Also, I thought that only the 7ish M21 had knurling, and this one is a 12ish. All the silver factory plating is still intact, including in the throat, so it hasn't been re-bored. It is marked with only the standard King logo.

This piece sure looks factory original. Any ideas about its history ?

[MuscleMouth]

I’ve got a King 28, 12C, M21, M31, and 11M. There’s a #24 out there. I’d have to grab some calipers to get specific, but I’ve had a very hard time finding any true specs for King mouthpieces. Chris Charvat at the H. N. White store on eBay (hnwhitecompany) may be the only person I know who might be qualified enough to answer this. I don’t think they really sell mouthpieces, but they keep a stock of them to sell with the instruments. They do however have a lot of the original specs as they’ve kept everything in the family. If he has the time to answer you, he might know.

[CharlieB]

I'll check that out.
Thanks for the lead.

[jbeatenbough]

I have one King M21 mouthpiece. It came with a 1946 2b that I'm the second owner of and is in really good shape. It matches to your second description "7ish piece with knurling at the rim and at 1 3/4" from the stem end. Bore = 0.227". Perhaps that will help you date yours?

The variance in mouthpieces of the same brand/size bothers me, but apparently many brands have either been sloppy with quality control or changed their own specs from time to time.

[Nobbi]

If you can find out details about series and dimensions of King mouthpieces, CharlieB, please post it since I am very interested as well.
Thanks.