Tool for crimping/swaging 1/4" steel wire with couplers

[BBadger]

I'm trying to build part of an art piece using some 1/4"-diameter stainless steel wires (solid core) formed into hoops connected by 0.4"-diameter stainless steel couplers (see pictures below), essentially creating hoops like these myself.

I've purchased the wire and the couplers, but I'm unsure of the proper tool to crimp these couplers. From my research on the web, there are steel cable swaging tools for steel cable ferrules, but those are usually for cables, not solid-core wire. I've also seen references to hydraulic crimpers, but these appear to be mostly for softer metals.

Can anyone advise on what I could use for crimping these couplers? Here are some pictures of the wire and one of the crimpers for reference. The wire is 0.25" in diameter, and the coupler is 0.4" in diameter uncrimped.

Thank you for any advice on this!

coupler1.jpg

coupler2.jpg

[Joeln]

This is the kind of thing you need.
Swage tool
Not cheap at $230. If you only need to make a few it might be cheaper to find a vendor that does this work. Most larger cities will have someone who makes this kind of stuff for industry.

[ygmir]

if the hoops are not in a life and death/injury situation, I've had fine luck with a hammer and sometimes a chisel type thing. Or just a hammer.

[some seeing eye]

Why not weld it?

[Meat Hunter]

Try the mechanic at a small airport.

Probably more important than the swagging tool, is the cable slicer. A bar cutting tool or a hacksaw just will not to the job.

For a few bucks, they most probably will do the slicing and swagging for you.

[LukyPhil]

Badger I dunno if crimping this will work you may have to weld, the dudes in the tool room say 1/4" rod bullet ends and eyelets are forged.

I had a look at the bench mounted hydraulic swager out in the workshop and the stainless steel wire rope crimping dies only go up to 5.5 millimeters (7/32") and that's a 4 ton press. I'm not sure how much pressure is required but I expect the hydraulic assist needed for a 6.35 millimeter (1/4") crimping die would be a substantial increase over that needed for 5.5 mm.

You need to also take into account that stainless steel wire rope compresses and deforms when it takes the crimp, where 1/4 inch stainless steel rod will not. If you do crimp to solid rod it can be decorative only and can not be put under load.

[LukyPhil]

Just showed the images to the toolmaker:

Have you considered threading them together?

[Traveller in Time]

I am with the hammer.

Indeed all crimp tools I know of are intended for steel cable. Even the tube crimper of the central heating workers at 1" only has tubes.

Use edge on anvil and heavy hammer to dent on opposite sides, rotate 90 deg and make another set of dents at some distance.

[BBadger]

Thank you all for your advice. It is really helpful!

It seems the swaging tool may not work since these are not actual cables and may not hold a crimp. If the swaging tool is sufficient, $230 will probably be a workable investment. I'm trying to build two sets of hoops: 12x that are 3.5-foot in diameter, and another 12x that are 2-ft in diameter. The coil of wire I received is 2.5-feet in diameter which causes the larger diameter hoops to push inwards, while the 2-ft diameter hoops will pull outwards.

I might be able to get away with swaging or hammer-crimping (I've been wanting a nice anvil anyway), as suggest above, for the larger hoops. The only stress they'll be under (and it won't be that much) is compression. Having some additional friction just to make sure they don't accidentally pop out might be enough.

I'm not so sure about the 2-foot diameter hoops. They'll want to pull out of the coupler because of the spring forces. If the crimps end up as decorative, as suggested by LukyPhil, they may not stay in position. Will they hold?

Would some kind of epoxy work? I don't know how to weld, and don't have access to a welder (doing all this out of an apartment). I could probably enlist the services of people in the local burner community or find a welding service somewhere. If possible, I'd like to be able to do it myself, but given the resources at my disposal that may not be possible.

Probably more important than the swagging tool, is the cable slicer. A bar cutting tool or a hacksaw just will not to the job.

I've been able to successfully cut the cables using a bolt cutter (originally for some cheap chain loops for lag screws). So far, the bolt cutter seems to have held up. That steel is pretty damn hard!

Have you considered threading them together?

Hmm, there's an idea. I could tap them for 1/4-20 and see if they can be coupled together that way. The wire/rod has curvature, but maybe for short lengths it could. Another problem is that the couplers help keep the ends of the wire parallel (end-to-end) with each other, otherwise they would buckle. I don't know if short lengths of threaded couplers would work. Maybe I can rig something to bend that part of the wire to straighten it out though.

Would putting some threading on the ends and then crimping to them improve the grip enough?

Thank you all again for your help. This is much appreciated!

[ygmir]

if you could drill it, you could just pin each one into the coupler.

[ygmir]

if you're in Portland, I'll be up there next week, and a bunch of us are meeting at
http://www.radioroompdx.com/
on the 14th for dinner and drinks. You'd be welcome.
If Espresso Dude is there, he is a brilliant fabricator, so may be able to advise/help.
Also Foxfur. I'll ping them both and see.

[BBadger]

Ah dammit, I wish I could! I'll be visiting the folks that weekend and a few days before.

I like the pin idea though. I'd really prefer something like threading or welding, but It might give just enough hold with possible crimps to prevent the ends from coming out and having the hoop fall apart.

[Traveller in Time]

Threaded

Inner diameter of the tube should be less then outer diameter of rod (they are not as OP writes)

Now I can ont get it out of my head trying to comprehend the mechanics.

Cutting a thread inside in some tubes, ferrules OK.
Cutting a thread outside of a rod OK.

Here I get knotted up: both the tubes and the rod are to be curved. I can not cut thread in a loop!

Imaginary thread on the ends of a rod curved to make a circle, now I screw on the tube on one end.
It will lock at the end of the cut about halfway in the tube.
Screwing the other end will unscrew the first.


(not sure screw is the right word: turn, drive??)

[Jackass]

Threaded

Inner diameter of the tube should be less then outer diameter of rod (they are not as OP writes)

Now I can ont get it out of my head trying to comprehend the mechanics.

Cutting a thread inside in some tubes, ferrules OK.
Cutting a thread outside of a rod OK.

Here I get knotted up: both the tubes and the rod are to be curved. I can not cut thread in a loop!

Imaginary thread on the ends of a rod curved to make a circle, now I screw on the tube on one end.
It will lock at the end of the cut about halfway in the tube.
Screwing the other end will unscrew the first.


(not sure screw is the right word: turn, drive??)

No, you're right. The threading together idea could only work if the two ends of the coupler were able to turn independently of one another, like a swivel. Otherwise as you screw one side on, the other side will unscrew... If it were me, I'd have those welded. It won't take much at all, just a good tack weld on each end of the coupler.

[LukyPhil]

No, you're right. The threading together idea could only work if the two ends of the coupler were able to turn independently of one another, like a swivel. Otherwise as you screw one side on, the other side will unscrew... .

Not exactly, the ends are threaded independently, one left one right then the tube is one half left one half right in a configuration called a "turnbuckle". As the tube is turned the ends are drawn together.

........Would some kind of epoxy work? ..........!

Yep, Epoxy this product will do it. https://www.jbweld.com/collections/meta ... -twin-tube

On relaying the new information to the grey coats next door in manufacturing the consensuses is cut a circle to the diameter desired in a sheet of marine plywood board then calculate the circumference (C=2π r) measure cut and clean the rod, ruff up the ends to be glued with a file, lay the rod into the wooden form with the joiner and bond. leave to set for a minimum of 10 hrs.

Strength of the join will not be a problem tensile strength is 27,000 kpa that's about 4,000 psi but as the hoops haven't been rolled they maybe prone to buckling so they may not lay totally flat when nocked free of the wooden form.

[Jackass]

No, you're right. The threading together idea could only work if the two ends of the coupler were able to turn independently of one another, like a swivel. Otherwise as you screw one side on, the other side will unscrew... .

Not exactly, the ends are threaded independently, one left one right then the tube is one half left one half right in a configuration called a "turnbuckle". As the tube is turned the ends are drawn together.

Well shit, all I have are RH threading tools. Now you're getting kinda fancy, the tendency to cross-thread might be a factor as well...

[Traveller in Time]

You are both right

I know the two handed threaded tubes as stay tensioners, they are possible.

I also only have right hand bits (for inner) and discs (for outer)

[BBadger]

Not exactly, the ends are threaded independently, one left one right then the tube is one half left one half right in a configuration called a "turnbuckle". As the tube is turned the ends are drawn together.

Yeah I was thinking that turnbuckles achieve these kinds of results (couldn't remember what they were called off the top of my head), though it'd be a pain to get right on these hoops, and a bit overkill as I don't need them to tension-adjustable.

Yep, Epoxy this product will do it. https://www.jbweld.com/collections/meta ... -twin-tube

On relaying the new information to the grey coats next door in manufacturing the consensuses is cut a circle to the diameter desired in a sheet of marine plywood board then calculate the circumference (C=2π r) measure cut and clean the rod, ruff up the ends to be glued with a file, lay the rod into the wooden form with the joiner and bond. leave to set for a minimum of 10 hrs.

I think this will work for me, given the resources I have. The 3.5-foot diameter hoops should be able to hold shape and won't need the form, but I'll definitely need something for the smaller 2-foot diameter hoops.

All this has been very helpful! Thank you all for your help with this!

[motskyroonmatick]

I'm thinking braising or soldering right now since it doesn't need to be that structural...and honestly I've never braised or soldered stainless steel. Ive always welded it with a MIG or TIG welder. For larger pieces welding would be appropriate but for smaller pieces welding the wire to the coupler could introduce a stress riser that would make the wire break with only a few flexes.

Or

Stainless gets very soft when heated red hot. You could heat the coupler with a map or propane torch, insert the wire ends and then hammer on the coupler as Ygmir suggests. If not overheated the stainless would shine up relatively easy after the heating and I think would yield a strong connection. Stainless stays hot for a really long time so be careful with heated pieces if you try this process.

Or

A large worn out pair of bolt cutters could be used to crush the tube on to the wire much like the cold chisel suggestion but acting from both sides.