Cutting excess barb threads

I just got some new barbs in from McMaster and the threaded ends are about 4x longer than I need. For looks, I'd rather not have the barbs sticking out that far from my WB's. Is it ok to cut the threads down with a dremel tool, or is there a better way?

Try to run a nut all the way on before you cut the threads, just to be safe. When you back it off, it will make sure the threads arent too messed up. Most likely just cutting the threads will mess them up some.

That is unless you have thread dies.

Edit: I would use a die grider, but a dremel would work.

Edit2: Those are probably tapered threads so the nut idea might not work. Its worth a try though.

If you're talking about tapered (NPT) threads, then you have no recourse except to use a die (as in tap-and-die) to narrow the fitting, and then a saw and file to cut it short and smoothe the end.

I've cut the threads off NPT barbs by putting the barbed end into the chuck of a drill press, and sliding a hacksaw blade along the table of the drill press to do the cutting. I got a nice clean cut that didn't need any cleanup. Wrap some tape around the barbed end to keep the chuck from biting into the brass.

Be aware though, that if the thread is tapered, (e.g. NPT) then the top of the block is going to have to be tapped deeper to accomodate the wider threaded portion. If the top is copper, that tapping is going to be a real chore.

(Or, you could use a die on the barb as omaticrail said. If you need to get the tap anyway, you can save the price of the die though, and tap deeper.)

Thx for the advice. I'll just wait till I'm home over Thanksgiving. I'm sure my dad will have the right tools to do it.

Just incase my dad doesn't have the die and/or tap, could someone give me a link to what I'd ned to buy? The barbs are 1/4" NPT and the threaded part is litttle over 1/2" long. I'd need to cut it down to the length that the barbs on DTek blocks are.
I got the barbs from McMaster, they're on p218. They grip extremely well.

Yeah!!! you got the right barbs!!!

Finally, someone will be able to validate these using PushOn barbs!!

Yes, you can cut them down. I've done that exact thing.
If you have to use a 1/4 NPT tap, tap it down to where there
are 3 1/2 threads showing. You should be ok then. Then what I did was thread in my barbs, cut them off with a die grinder and sand them smooth on the belt sander.

I have to disagree that it will be a chore to tap the top if it is copper. Just use some type of lubricant when using the tap and you'll be just fine. I used CRC 626. The copper is like butter when
using CRC. Also, I used a 1/2" bit instead of 37/64" bit.
A tip when tapping, turn the tap handle 1/8 to 1/4 at a time clockwise when cutting then go 1 full turn counterclockwise to remove the burrs. Do that all the way until the 3 1/2 threads are showing.

Now with those barbs, you won't need clamps....but I'm sure you
already found out since it sounds like you tried them out.

Ok, I'm a little confused. So I'm going to have to cut down and re-thread the barbs, and also re-thread the top of my WW? The top of my WW is annodized aluminum. My father has a die and tap set, so I've got what I need.

Yeah!!! you got the right barbs!!!

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Ya, those things are awesome. They're extremely secure. Once I put them on all the way I have a feeling I'll have to cut them off. No more messy silicon and metal clamps for me

no you won't have to 're-thread' just 're-tap' your top. You'll want to 'chase' the threads on the barbs with the 1/4 NPT die so they are free of any burrs. Especially since they are brass and the top is aluminum...you don't want to cross-thread them in the top then you'll never be able to seal it.

remember to use cutting oil and go down with the tap until about 3 1/2 threads on tap are left. you should be ok then. You'll be able to see how deep the barbs thread in so you can make adjustments as needed.

If you have use of a die grinder with cutoff wheels, they work great for shortening the barbs.

I just cut my threads completely off and butt-brazed the barbs

squeakygeek said:

I just cut my threads completely off and butt-brazed the barbs

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Hows that work on aluminum? Id bust out the bench grinder...heh actually i did this exact same thing the other day. bzzzzzz

Mikeonatrike said:

Hows that work on aluminum? Id bust out the bench grinder...heh actually i did this exact same thing the other day. bzzzzzz

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I'm not sure if it would work with aluminum. I would try it on a scrap piece first. It kind of peeves me when manufacturers put aluminum tops on copper blocks instead of copper tops. You're just asking for trouble putting an aluminum top on a copper block.

squeakygeek said:

I'm not sure if it would work with aluminum. I would try it on a scrap piece first. It kind of peeves me when manufacturers put aluminum tops on copper blocks instead of copper tops. You're just asking for trouble putting an aluminum top on a copper block.

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Ditto to that, its either copper or lexan for my blocks.

I think I saw a thread somewhere were someone was selling aftermarket copper top blocks for the DTek WWs.

feyd83 said:

I think I saw a thread somewhere were someone was selling aftermarket copper top blocks for the DTek WWs.

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Hmm sounds profitable.