Imperial rigging wire and metric turnbuckles

[cutlass]

I'm just about to get the rigging replaced on my 39' catamaran and the rigger has said he will use imperial gauge wire with metric gauge turnbuckles

Is this ok? I'm just concerned the crimp won't be a perfect fit

Thanks!

[cutlass]

actually I got it the other way around! Its metric wire with imperial turnbuckles.

The rigger suggests:

14mm wire with 7/8" turnbuckle
12mm wire with 3/4" turnbuckle
8mm wire with 5/8" turnbuckle
10mm wire with 5/8" turnbuckle

with the fit be good enough once crimped?

I really appreciate everyones opinion

[Stumble]

Get a new rigger!

The parts aren't the same size,they are close, and may work, but absolutely not the same size. And any decent rigger should know better.

Swagging relies on the parts cold forming (or cold welding) together to form a continuious mass of steel to function properly, a mis-sized part can do one of two things.

1) doesn't allow for enough compressive force to properly form the parts together, which will allow free space in the swag. This can allow eithe the roots of crevice corrosion to take over and destroy the part, or for the two parts to slip past each other under load and separate.

2) over compressing the part, which can cause micro fracturing of the part, and will lead to premature failure.

If he insisted it will work, ask for the manufacturer of the parts he is using, and call them to ask if they will stand behind a warranty if it's done this way. I don't know of a company that will (we certainly won't).

[cutlass]

Thanks!

[barnakiel]

IMHO metric wire / imperial turnbuckles are a perfectly valid way to go.

I have seen swage type terminals of at least one top notch brand that were quoted in metric/imperial wire with imperial thread.

Blue Wave Marine 2011

The opposite (imperial wire/metric thread) I have not seen though.

BTW Our boat is metric wire/imperial turnbuckles too.

b.

[Stumble]

When a manufacturer makes a part that is designed to fit both, then sure it's fine. When a manufacturer doesn't doing so is a mistake.

Blue wave designes their parts to fit both metric and standard wire, in which case it isn't a metric swag fitting.

Personally I still don't think they are as good as ones that are specific to the wire size being used, since by necessity the tolerances have to be different.

[roverhi]

My old boat has done more than 30,000 miles with metric norseman terminals on imperial wire. It's no big thing.

In any case, it's not the turnbuckles that could be an issue but the swage studs that will connect the wire to the turnbuckles. If it was me, I'd use Norseman/StaLok terminals. 6mm=1/4", 7mm=9/32", 10mm=3/8". Would have to verify what the other sizes of metric fittings convert to in imperial wire. Do the rigging yourself and save a few bucks. It's really easy to fit Norseman/StaLok terminals.

[david samuelson]

My 2 cents worth: What does your rigger mean by "metric guage turnbuckles"? What part is matric?
Today, most of the reputable turnbuckles produced have a right-hand thread (swage or swageless stud) at the top and left-hand (toggle or fork) at the botton. By far the most common have imperial threads and imperial clevis pins.
Now we come to the terminal that joins the wire to the turnbuckle (that's the stud): if the wire is metric the swage or swageless stud MUST be made for metric wire. If the wire is imperial the stud MUST be made for imperial wire. (The exception: 8mm and 5/16" are usually interchangable). So you can have a stud for metric wire that has imperial thread and vice versa. But try to avoid metric threads if you are travelling - you may have a hard time to find replacements.
The corresponding sizes that you mentioned in your second post Cutlass are good.
I believe your rigger is OK, we were just confused in the interpretation.
Happy sailing.

[cutlass]

Thank you so much everyone!