Originally Posted by
Chris Waters
Hello from us at HBC here in Blighty!
As players and as engineers, it's been rivetingly interesting over the years to measure the threads for all the Euphoniums we make 4th HBCs for. To calculate the thread for each instrument, we measured the thread pitch, real pitch, crest flat, crest radius maximum, root radius, thread depth, flank length, major diameter, minor diameter and pitch diameter. The final calculation involves modifying those dimensions to cater for the 24 microns (μm) of silver plate we apply to each 4th HBC and from this, the thread can be cut and HBCs electro-plated. 1 mincon = 0.001 mm or in Imperial 0.00003937". God bless the Zeus Engineering Handbook - invaluable!
There are currently eleven Euphonium Brands that we make 4th HBCs for, with these Brands being sub-divided into various Models of Adams, Besson, Boosey & Co., Boosey & Hawkes, Geneva, Hirsbrunner, John Packer, Sterling, Wessex, Willson and Yamaha. Within the Brands/Models there are also sub-divisions of thread size; for example there are no less than three different threads for the current Besson range, with the Prestige 2051 being different to the Prestige 2052. Equally so the Yamaha Professional and Neo Models have a different thread to the Custom.
There's no surprise of course that most Chinese manufacturers like Jinbao copied the Bauerfeind valve group dimensions for Euphoniums and other brass instruments, as evidenced through our thread measuring of their instruments.
An astonishing find was that from 1923 to 1994+, the Boosey & Co/Boosey & Hawkes 4th Euphonium thread remained the same! We measured a Boosey & Co Class A Solbron Imperial Euphonium serial number 112137 made in November 1923 and not only was it the same as a 1982 Boosey & Hawkes "Round Stamp Globe" Sovereign but as a 1994 Edgware production Besson Sovereign too! Obviously in 1923 it was an Imperial thread and the same dimensions used through to 1994/possibly a bit beyond (sensible engineering). ISO metric threads then took-over with German production of Besson.
We also make 3rd HBCs for Sopranos, Cornets, Flugel Horns (3rd & 4th) and Tenor Horns, varyingly for Adams, Bach, B&S, Besson, Boosey & Hawkes, Couesnon, Courtois, Eclipse, Geneva, John Packer, Schilke, Sterling, Stomvi, Taylor and Yamaha. 'twas the same calculation process for each, so we now have a very detailed database of virtually all casing/bottom cap thread dimensions. It's taken years, but has been and continues to be great fun and we feel we're helping fellow brass musicians worldwide. High quality and good customer service are our cornerstones. It won't make us rich and that's not the object of the exercise, but we're helping - and that's the object of the exercise.
In development are HBCs for Baritones (a REAL challenge due to the minimal gap between the lower face of the standard bottom cap and the pipework) and for Tubas.