TromboneChat

Where do you measure the bore size on your horn? I have a vintage Holton Model 63 Tenor with a dual bore slide. I have never been able to find any of the specs on this horn other that a few vague "I think it's this or that". So, where do you measure the bore size? Thanks.

If there are soldered-on stockings you can measure the end of the inner slide. Extruded stockings may not be as accurate.

Failing that, you can measure the lower tube at the joint with the bell section.

Best way is a deep reach inside caliper.

BGuttman wrote: ↑Tue Oct 23, 2018 1:51 pm If there are soldered-on stockings you can measure the end of the inner slide. Extruded stockings may not be as accurate.

Even with soldered-on stockings, having inner tubes that don't go all the way to the end of the stockings is not uncommon.



You can mesure the outside diameter and substract twice the wall thickness (but then you need to measure the wall thickness which might not be much easier...)

Model 63 should be a dual bore 0.480-0.495" with a 7-1/2" bell.