On Shanks

I want to clear up a few things about mouthpiece shanks and give my actual dimensions I use.

1 - There are a lot of european horns that use American-style (or american-compatible) leadpipe receivers.  These include Engelberg Schmid, Paxman, and Rico Kühn.  For these models of horn we recommend the G or C series in American shank.

2 - There are a few models of horn for which we've noted extensive variation in leadpipe fit.  For these they should be checked specifically when ordering.  On most Yamahas American shank horns fit better, but we've seen some variability with the dual taper receivers and if you think your mouthpiece goes in unusually far it's worth reaching out.  Hans Hoyer in recent years has been putting receivers that are much smaller than other makers on their instruments.  If you have a recent Hoyer and feel like your piece isn't going in very far it's definitely worth reaching out.

3 - Mostly only Alexander uses a true "Euro" shank; ie one with a metric taper angle.  That's why we call it a "Mainz" shank and not a "European" one.  If you have an Alex, you'll definitely want an M shank over a G series.  C series come both ways.

Now on to the actual specs; what is a european shank?  It's one that uses approximately a 1 degree rate of taper on the walls (vs vertical so 2 degrees for both).  The "choke" (the dimension of the piece just above the end of the leadpipe) is similar on M and American shanks but the tip is much bigger on M shanks because of the slower rate of wall convergence.  This has some implications for back bore design (they're naturally more open with the same curves because they have a bigger tip opening) and that's one area where we can improve the playing of a piece when moving between shanks.

An American shank mouthpiece uses approximately a 1.5 degree taper angle.  Regardless of the shank, we want our mouthpieces sitting around 17mm deep (15-19 is the acceptable range).  We specify them for the measurement 15mm from the tip of the shank (because it's easiest to specify the small end of the range.  So if you're recreating our shanks in CAD you want to use the following setup.

M shank - walls are 89 degrees from horizontal, 15mm up from the tip you want 8.25mm at the smallest "choke".  We specify the shanks to be 25mm long aesthetically, but any more than 19mm is to personal preference.

American / Morse Shank - walls are 88.5 degrees from horizontal, 15 mm up from the tip you also want an 8.25mm "choke".  (You'll notice this gives you a smaller tip than an M shank.  You should get 7.47mm if you've done it right).

French - Same 88.5 degree taper of the Morse shank, but with an 8.17mm choke.  You'll want a longer shank length (we use 30mm) to accomadate varying fits of historical crooks.