Nasty nipples

[waltermrich]

I bought stainless wires from Wag Aero a few years back and they threaded easily onto the old nipples.

[astjp2]

The internal are cut. You can't roll an internal thread (to my knowledge!).

Bruntons (Scotland) are the company who took over streamline wires from Macwhyte wire company; every streamlined wire in the world comes from Bruntons now. Maybe round wires come from others, but I doubt it.

burls and wag aero make a round wire, supposedly burls has an adapter to roll threads on a lathe. Not sure about wag.

[Robert Lees]

When I purchased ten sets of round tailbrace wires from Bruntons about 15 years ago, they told me that streamline wires were easier to get to the correct length.

This is because they all start as round wire, and once the round wire has the rolled threads added, that's it! The length is fixed.

But for streamline wire, after rolling the threads, they then pass the round wire through rollers to give the streamline shape. There is enough tolerance on the width & thickness of the streamline cross-section to fine tune the finished length very accurately!

But the process of rolling the shape introduces "waviness" in the wires; these are corrected by hand with a soft mallet and a lead-shot bag. That's a lot of work for long wires for vintage aircraft like a Stearman or Butler Hawk.

Rob

By the way, Bruntons made all new nipples, half-moons and lock nuts too, all certified. They do all the drag/anti-drag wires too.

[Woody]

Here is an excellent short video showing rolled vs cut threads

https://www.youtube.com/watch?v=rwArBBcUNr4

[Robert Lees]

Thanks, Woody. That shows it exactly!

Rob

[Scott]

It's pretty easy to tell if the wires have cut or rolled threads. Rolling extrudes the metal and the threads are larger in diameter than the base wire.

Precisely, this is why the cut wires will screw into stock nipples (with how much clearance?) but the aftermarket/stainless nipples won't go on the original wires.

[Woody]

I haven't seen the wires from wag aero, but I think they are rolled. I got the number of their supplier and he made me some special length drag wires for my clip wing. They are rolled threads. I'm not sure the theory about the nipples is right. All of the threads are the same diameter. The base stock is smaller for rolled threads. The nipples should fit either.

[Woody]

It may be a misprint but one vendor shows nipples as 8-32. The wires are 8-36. That would explain it.