Tapered hole on end of shanks

Just if anyone knows if the tapered slot on the end of shanks is for any other purpose that for the plunger of the faucet to slide into?

I'm going to be manufacturing a SS shank and that's about the only portion I can replicate.

If it is crucial to flow I'll be SOL but if not, I'll make it a round hole

Hazarding a guess, I would say it's purpose is two fold.
Clearance, and directing the flow, to cut down on turbulence.

Are you a Machinist, or have access to machine tools?
Looks like you could rough it in with a twist drill, and then chuck up a ball mill of the appropriate radius to get the recess.


Edit: Looks like the beer flow would exit from the plunger almost perpendicular to it's intended path, and could use some "re-directing".

I've got access, I'll be doing the trying myself.

I've got some ball mills but nothing with a taper that deep.

For as simple of a part as it is I think I'll make it and try it and see how it goes.

I'm leaving off the knurling on the shank to, I don't think it serves a purpose for my application.

Here's a shot of what in after.

Edit: I might be able to get in there with a chamfer tool and cut a small taper

It looks to me as if that is just the drill point angle. Since the hole is clearance only it was probably drilled and not bored or milled out.

Personally I would take bar stock, drill out that counterbore, drill though, chamfer the right end, OD turn the right half and put in the groove in a first operation. Then flip end for end and turn the larger OD and thread that side. Don't know about the spline without custom tooling.

That's pretty much exactly how i made it yesterday.

I'm omitting the spline because I don't think it's required.

The taped on my purchased shank is way beyond a drill point. But after making it that's what I left it as. Went 1/2" deep after the bit was fully engaged so I ended up with something like 5/8" or so

I wasn't happy with the part so I'm going to try another one at lunch.

I don't know how to single point, running a die over 316 is a B&)!?

The spline is what keeps the faucet from rotating.

Mmm ya I agree....

But I would also argue I can hold the tap stable with my hand and tightened the nut to sufficient torque to hold without the gnarling

Time will tell, planning to have it read to try this weekend