[tempesax]

My repairman told me that when you hammer a piece of metal you cause the molecules in the metal to "anneal", meaning that the molecules in the lattice become better aligned, forming a more perfect lattice, and thereby allowing the bell to vibrate more like a single crystal, rather than like several different pieces of metal soldered together. Whereas when you hydroform the metal, annealing does not occur. Therefore, horns made by hand hammering vibrate better than those made by hydroforming.

On researching his answer, I think he is only partially correct. Annealing does not occur due to the hammering. Annealing is caused by heating the metal which softens the metal. (https://en.wikipedia.org/wiki/Annealing_(metallurgy)).

In fact hammering the metal causes the metal to harden and can cause imperfections to develop in the lattice.
(https://www.halsteadbead.com/articles/work-hardening-annealing).

However, it seems that metal workers alternate hammering the metal which causes it to harden, with heating the metal which causes it to soften and therefore anneal.

So I think that what my repairman was trying to say was that the process of alternating the hammering with the heating causes the metal to anneal, whereas hydroforming does not require heating and therefore does not anneal the metal, and this is why horns made by hand hammering vibrate better than those made by hydroforming.

 

[Alain Gen]

My repairman told me that when you hammer a piece of metal you cause the molecules in the metal to "anneal", meaning that the molecules in the lattice become better aligned, forming a more perfect lattice, and thereby allowing the bell to vibrate more like a single crystal, rather than like several different pieces of metal soldered together. Whereas when you hydroform the metal, annealing does not occur. Therefore, horns made by hand hammering vibrate better than those made by hydroforming.

On researching his answer, I think he is only partially correct. Annealing does not occur due to the hammering. Annealing is caused by heating the metal which softens the metal. (https://en.wikipedia.org/wiki/Annealing_(metallurgy)).

In fact hammering the metal causes the metal to harden and can cause imperfections to develop in the lattice.
(https://www.halsteadbead.com/articles/work-hardening-annealing).

However, it seems that metal workers alternate hammering the metal which causes it to harden, with heating the metal which causes it to soften and therefore anneal.

So I think that what my repairman was trying to say was that the process of alternating the hammering with the heating causes the metal to anneal, whereas hydroforming does not require heating and therefore does not anneal the metal, and this is why horns made by hand hammering vibrate better than those made by hydroforming.

"Molecules" in a metal? I agree, your tech is only partially correct!

 

[milandro]

a little knowledge is dangerous

 

[turf3]

My repairman told me that when you hammer a piece of metal you cause the molecules in the metal to "anneal", meaning that the molecules in the lattice become better aligned, forming a more perfect lattice, and thereby allowing the bell to vibrate more like a single crystal, rather than like several different pieces of metal soldered together. Whereas when you hydroform the metal, annealing does not occur. Therefore, horns made by hand hammering vibrate better than those made by hydroforming.

On researching his answer, I think he is only partially correct. Annealing does not occur due to the hammering. Annealing is caused by heating the metal which softens the metal. (https://en.wikipedia.org/wiki/Annealing_(metallurgy)).

In fact hammering the metal causes the metal to harden and can cause imperfections to develop in the lattice.
(https://www.halsteadbead.com/articles/work-hardening-annealing).

However, it seems that metal workers alternate hammering the metal which causes it to harden, with heating the metal which causes it to soften and therefore anneal.

So I think that what my repairman was trying to say was that the process of alternating the hammering with the heating causes the metal to anneal, whereas hydroforming does not require heating and therefore does not anneal the metal, and this is why horns made by hand hammering vibrate better than those made by hydroforming.

Wow, that's not even wrong. I don't even know where to start correcting the misconceptions of metallurgy presented.

 

[Gordon (NZ)]

Of course a hydroformed bell could still subsequently be annealed if that were important.

However experts say it makes no differenced to a sax, any difference being inaudible.
Possibly a slight difference for a brass family instrument.
And quality cymbals have all manner of secrets associated with their manufacture.

 

[Dr G]

My repairman told me that when you hammer a piece of metal you cause the molecules in the metal to "anneal", meaning that the molecules in the lattice become better aligned, forming a more perfect lattice, and thereby allowing the bell to vibrate more like a single crystal, rather than like several different pieces of metal soldered together. Whereas when you hydroform the metal, annealing does not occur. Therefore, horns made by hand hammering vibrate better than those made by hydroforming.

On researching his answer, I think he is only partially correct. Annealing does not occur due to the hammering. Annealing is caused by heating the metal which softens the metal. (https://en.wikipedia.org/wiki/Annealing_(metallurgy)).

This is not a terrible reference. Please read it.

Annealing is heating. Which processes (dislocation recovery, recrystallization, etc.) occur due to heating depend on temperature and time.

Either case may leave residual stresses in the material, either case may result in grain texture and spatial variations in morphology (ex. pancake grains vs equiaxed).

Thanks for showing an interest in materials science. It is a fascinating field that many of us here have enjoyed as a career.

 

[Mark Fleming]

What I found most interesting in the video posted by milandro was at 3:10. After all of that careful craftsmanship, the high F key is finally adjusted by torquing on it with a pair of pliers. It is a quick clip, but it shows that even precision construction sometimes needs a little tweak. The only unique part of of the clip is that they kept it in the video. I don't know why key bending bothers some, especially after watch in a video of hand hammering the body tube and claiming that controlled bashing makes for a better sax.

I've got two nearly identical Martins. Maybe they are hand hammered, I don't know. Maybe I could try hammering on one and report any perceived changes. I know that my hand-yanked keys improved them.

Mark

 

[pknight]

My repairman told me that when you hammer a piece of metal you cause the molecules in the metal to "anneal", meaning that the molecules in the lattice become better aligned, forming a more perfect lattice, and thereby allowing the bell to vibrate more like a single crystal, rather than like several different pieces of metal soldered together.

Are we talking about a saxophone bell? Why would you want a saxophone bell to be vibrating? Even if we are talking about sympathetic vibrations, the necessary frequency to cause such vibrations would depend on the overall length of the instrument, and the frequencies of most (all?) notes on a sax, determined by the effective length of the vibrating air column within the instrument, would not be adequate to set up such sympathetic vibrations. The sax is not a mallet percussion instrument.

Now, if you are talking about a hand bell, or a tubular bell, then perhaps.

this is why horns made by hand hammering vibrate better than those made by hydroforming.

I guess you were talking about saxes.

 

[Pete Thomas]

Are we talking about a saxophone bell? Why would you want a saxophone bell to be vibrating?

I would wonder about that also. If something on my saxophone/s feels like it is vibrating, then my first thought ios to take it to my tech to get it fixed.

 

[tempesax]

I’m not saying that I agree with my repairman, as I have read all the scientific reports that say that the material a horn is made of does not matter. However, he is a very good repairman and I hadn’t seen anyone bring up the “hand hammering + heating causes annealing” argument on this thread, so I thought I would report what I had heard.

 

[turf3]

Hammering (whether by hand, or by machine) causes WORK HARDENING, by distorting the grain structure of the metal. After too much work hardening, further stretching or bending will cause the material to fracture. Before that point's reached, the metal will be heated to ANNEAL it, which causes the grains to re-form with reduced distortion and reduced residual stress.

Hammering is the work hardening part. Re-heating (usually to a red heat, then permitting slow cooling - but I am not an expert on the forming of brass) is the annealing part. The degree of "annealed state" versus "work hardened state" in a finished part of formed metal depends on when the last anneal cycle was performed and how much work hardening occurred after that. This would be driven by the manufacturer's process details.

Furthermore, I suspect that the vast majority of saxophone bells go through a final die forming process to reach final dimensions and smoothness.

Your repair guy has the basic metallurgy all fouled up.

 

[Dr G]

Here's the Selmer video:

 

[BH9]

Hand hammering causes the brass to form artisanal molecules.

 

[Gordon (NZ)]

... Your repair guy has the basic metallurgy all fouled up.

I guess somebody had to tell it straight.
But he still maybe a great adjuster of saxes.

 

[mijderf]

My repairman told me that when you hammer a piece of metal you cause the molecules in the metal to "anneal", meaning that the molecules in the lattice become better aligned, forming a more perfect lattice, and thereby allowing the bell to vibrate more like a single crystal, rather than like several different pieces of metal soldered together. Whereas when you hydroform the metal, annealing does not occur. Therefore, horns made by hand hammering vibrate better than those made by hydroforming.

Wow, you just can't make this stuff up (except I guess, in this case)! :twisted:

 

[turf3]

I guess somebody had to tell it straight.
But he still maybe a great adjuster of saxes.

I see no reason why a saxophone repairer HAS to understand metallurgy and the microstructure of brass. In some situations (repairing severe dent damage when there are multiple previous repairs), a practical understanding of work-hardening and annealing would be helpful, I think.

I would suggest, however, that it behooves all of us, if we don't know the technical details of how something works, not to just make something up.

 

[milandro]

another example of one whom has great credit and expertise for one thing but commenting about another of which he knows just as much as the next man.

This is like the vibrationalists quoting great players whom have ideas about the physics of what they play and while they are great players they maybe having no idea of what they are talking about.

Unless one is a metallurgist or an acoustician ( I am neither and would always take the advise of an expert over my own words) his guess is just as good as anyone else’s.

 

[Canadiain]

Also, a cursory google on the topic of actual bells (the ones that ring) indicates that they are far from single crystal, and that over time the cast materials used have evolved to become harder and harder, which happens to be something that annealing would typically have the opposite effect on by relieving any work hardening that had occured... I found it quite an interesting read.

Definitely NOT single crystal microstructure!^^^^^

http://www.foundryworld.com/uploadfile/20094132737377.pdf

Maybe we should be casting the bell from tin bronze, enough of this hammering or hydroforming!

 

[turf3]

It is exceptionally difficult and expensive to make large objects as single-crystal. It's only done where the demands for hot strength are extreme, as in exotic jet engine turbine blades. Bells (the ringing type) are ordinary castings and the grain structure is a function of the alloy, the casting process, any minor alloying elements added to control grain structure, cooling rate, and various other matters.

It's going to be basically impossible to draw any useful parallels between as-cast and machined cast brass/bronze, and rolled sheet brass subjected to various stamping and forming processes with occasional annealing in between the forming steps to prevent cracking. They're not even the same alloys. As far as I know saxophone tubes are made from rather ordinary and common brass alloys, just like anyone can go down to the metals distributor and buy.

 

[whaler]

When the Chinese stuff sounds like an old Selmer, you’ll convince me. I always hear the talk about about some Selmers being dogs but I’ve never experienced that. Maybe you played one that wasn’t in the greatest repair.
It’s difficult to compare the work of a few master craftsman to a company cranking out saxes.