Maxwell chainwheel, different chain standards

[LifesBetterWhenYoureBeating]

My boat came with a maxwell windlass and chain that I've used pretty regularly for several months, but the chain is old and needs to be replaced. I've measured it and I'm pretty confident it's 5/16 HT. It has G4 markings and these are the dimensions I got:

Wire diameter: 8.5mm
Inside Length (pitch): 26mm
Inside Width: 12mm

Just to be on the safe side I contacted maxwell who told me my chainwheel (3173/108) supports only 8mm DIN766 chain. Unfortunately, that chain is hard to get here and would cost almost $500 more than 5/16 HT.

I know that some windlass manufacturers make chainwheels that accept both ISO and DIN766 chain, so I'm wondering if maybe maxwell is just overly cautious? Does anybody have first hand experience using maxwell chainwheels with a different chain standard than they're made for?

Thanks in advance

[wrwakefield]

Here is a good source of concise chain info:

Chain – Cox Engineering

Here are the dimensions [mm] for 5/16" G43 and 8mm G40 chain links:

5/16": 8.4 | 26.2 | 12.95 [ISO G4]
8mm: 8 | 24 | 10.5 [DIN 766 and ISO4565]

If your gypsy truly is calibrated for 8mm DIN chain, then chances are the 5/16" ISO may slip, jamb, and/ or cause premature wear.

On the other hand, if it has been working acceptably with the old 5/16" G4...

In case this is helpful.

Cheers! Bill

[Pete7]

How about buying 3m of it, put a load on one end and test it going in and out over the gypsy?

[LifesBetterWhenYoureBeating]

Originally Posted by Pete7

How about buying 3m of it, put a load on one end and test it going in and out over the gypsy?

The supplier I'd use doesn't stock it and takes a month to bring. Maybe for a short length like 3m I can find someone who has it in stock

[s/v Jedi]

Originally Posted by LifesBetterWhenYoureBeating

The supplier I'd use doesn't stock it and takes a month to bring. Maybe for a short length like 3m I can find someone who has it in stock

They don’t have 5/16” G4? Find another supplier