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Lots of threads on stem thickness behind the button, but I see nothing on thickness on the other end.

When using delrin, how thin can you go around the tenon?

For starters, I'm sure this depends on whether or not you bend the stem.
input?

That's going to depend on the diameter and depth of your tenon as well as whether your stem is tapered or a saddle. Basically, you want it to be thin enough that you don't sand through to the tenon on your stem. Other than that, it's about what makes sense with the diameter of the shank. Also, some kinds of acrylic are translucent, which makes delrin visible when you get too thin. You don't want that.

But mainly, you just want to be sure your tenon won't fail. If you really want to test the limits, glue up a stem and rough shape it. Stick the delrin into a vise and see if you can break the area around the delrin by pulling on it.

I drill the tenon end with 4mm for the airway... And my tenon diameter is is 7 mm

I do this on both delrin and integrated tenons ... Unless they are army mounts.. Then no delrin and the tenon diameter varies from 9 to 11 mm depending in my bit used to drill the mortise

James

I think I wasn't quite clear. What I'm wondering is what is the limit on 'stem' thinness around the tenon. Whether 5/16" or 3/8" or whatever the delrin diameter, how tight to the delrin can you get before you risk kinking or cracking the stem when you bend it?

This is a TIAFO matter.

sounds more like a TIAFUYS matter

Too thin is when it breaks. The answer is subjective because only you can decide how much abuse you want your pipe to stand up to before this happens. More is better, with aesthetics being the limiting factor. Make it so it dont break.

I saw a real thin cumberland stem where the cumberland had sort of cracked around the delrin. It was only a mm or 2 thick.

calsbeek wrote:
When using delrin, how thin can you go around the tenon?

For starters, I'm sure this depends on whether or not you bend the stem.

input?

The fact that you're asking means you either don't have a sense of the proper proportions between a stem and its tenon, OR you don't have the right tools and/or materials to make a pipe with a small diameter shank and tenon and want to know how far you can "push" it.

There is no lower limit, size-wise, as long as the proper proportions are maintained. (I've re-tenoned any number of Group 1 Dunhills & similar without problems.)

As for pushing it, that's a categorically bad idea for a beginner. There's enough fish to be fried as is. No need to make things harder than they already are.

LatakiaLover wrote:you either don't have a sense of the proper proportions between a stem and its tenon, OR you don't have the right tools and/or materials to make a pipe with a small diameter shank and tenon and want to know how far you can "push" it.

Or both.



I'm not trying to push my own stems. I'm looking at beautiful stems on other people's pipes (e.g., Yeti) and wondering how far they push it.
I know Yeti is makes integral tenons (at least on some) but this is what raised the question for me in terms of those using delrin. That, and the fact that I didn't sand into the tenon on my last stem, but when I bent it, the stem buckled around the tenon, so clearly it was too thin.

Integral tenons mean you don't have to worry about these things as much. Yet another reason why I limit how often I use delrin.

I use 6mm almost exclusively and make stems down to around 10mm at times, though I don't recall if I have bent any that thin.

I use 1/4 inch as a general rule. Tenon size can change that. Large tenon, thicker walls.