What Anchor Shackle to get? Galvanized anchor shackle with G4 chain and stainless swivel

jssailem · May 3, 2021

@skunther I would not be too concerned. Perhaps the chain has been put away wet. The rust is not abnormal. So far it does not appear, in your image, to be eating away at the chain link.

Know that it is there and monitor it regularly. The link at the chain end gets a bit more action. If it appears to wear, cut the link back and reattach to your swivel. The links and the swivel are a consumable item. When they have significant wear they are replaced.

The rust appears to be surface rust and while unsightly the chain thinkness does not appear compromised. I can not see what it looks like under the swivel.

On my boat I would continue to use the rig while at the same time monitoring the parts.

Hayden Watson · May 3, 2021

To your original question, I have been very happy with my Mantus swivel.

dlochner · May 4, 2021

Get rid of the swivel, it is a weak spot in your ground tackle. While the swivel looks beefy if side loaded the tangs are pretty weak and will break. Also SS will fatigue and break without warning, galvanized steel won't, it will show sings of fatigue.

Terry Cox · May 4, 2021

skunther said:
I picked up a galvanized shackle as I understand it's better to use that with G4 chain, but what about the swivel?

Our 1991 boat came with 5/16" G4 hot dipped galvanized chain connected to a hot dipped galvanized swivel. Two years ago, after anchoring hundreds of times over the years, I noticed the swivel was showing some pin wear so replaced it with a new galvanized swivel from Defender. No sign of rust and very pleased with the corrosion resistance performance.

Shopped local stores for a USA made hot dipped galvanized swivel, but all were made in China and suspect. Defender confirmed they had the product I wanted. Also purchased a new rope thimble to swivel shackle to replace the old one, which was still serviceable, but felt it had served its job well; time to retire.

Rich Stidger · May 4, 2021

dlochner said:
Get rid of the swivel, it is a weak spot in your ground tackle. While the swivel looks beefy if side loaded the tangs are pretty weak and will break. Also SS will fatigue and break without warning, galvanized steel won't, it will show sings of fatigue.

I agree that with this pictured swivel there is a danger of side-loading. I bought one of these and then after reading about the side-load issue I returned it.

I have just purchased a Mantus swivel and the design of that swivel will not allow a side load. The reason I want a swivel is to allow the anchor to spin and orient itself right-side-up to be pulled onto the bow roller. Without a swivel the anchor always seems to come up backwards and requires a boat hook to spin it to the correct position. This will be my first year trying the Mantus swivel- I will find out if it works as I hope.

dlochner · May 4, 2021

Terry Cox said:
Shopped local stores for a USA made hot dipped galvanized swivel, but all were made in China and suspect. Defender confirmed they had the product I wanted.

The Brand is Crosby. Make sure you buy a size that is one size larger than the chain. Be sure to put the bow in the anchor and the pin in the chain. This helps prevent side loading the shackle.

thinwater · May 4, 2021

Get rid of the swivel. I have had that specific model crack due to side loading.

If you align the chain correctly and back slightly when loading the anchor (anchors align with the water flow--if you are going forward the anchor will always come up backwards) you won't need the swivel.

Matching stainless to galv always increases corrosion of the galv. The solution is to trim the chain every few years, as needed. Easy.

cptjak · May 4, 2021

You can keep the swivel if you put 6 inches of chain between the swivel and anchor there by eliminating the side load shear problem

Rich Stidger · May 4, 2021

I bought the Mantus S2 to use with my G4 5/16" chain. Until now I was unaware of the issue between galvanized and stainless but I will keep an eye on it.
A friend who has the Mantus S3 told me that one of the two seizing wires on the cup of the swivel had broken. Like me, he visually checks the seizing at every deployment and retrieve. I have never had any seizing wire fail in any application, but I will keep a close watch on these too.

Rich Stidger · May 4, 2021

skunther said:
How do you like your S2 so far? It seems like the most robust option, and also keeps the swivel right at the anchor by not necessitating a few links be added there to avoid side load strain. I will be very curious to hear how well it performs.

Still on the hard. Won't launch until the end of May. Stay tuned....

Hayden Watson · May 4, 2021

I really like my S2. I used to have problems with the anchor coming up onto the roller inverted but now it flips as soon as the shank starts up the roller.

Terry Cox · May 4, 2021

skunther said:
Which specific hot dipped galvanized swivel did you get from Defender (I assume 3/8")? I've looked over their website and am unable to find such a model. Does it swivel well, or does it tend to bind?

It swivels well, does not bind. Here is part of an article that I wrote awhile ago about the new swivel.

"Brought the anchor, swivel and shackle home yesterday after changing the oil in both engines, so that I could get a better read on the various components. A bit of a struggle removing the frozen pin from the shackle. Some WD-40, a hammer and a large wrench did the trick. So what I actually have is a 3/8" swivel, not 5/16". Time to also replace the shackle, which is also 3/8". Both have a 2,200 pound working load. Titan out of Canada makes the shackle and Chicago Hardware makes the swivel. Both are drop forged, heat treated and hot dipped galvanized. I trust Canadian made products. Hopefully, Defender will refund the 5/16" swivel."

Here is a link to the 3/8" shackle: TITAN Screw Pin Bow / Anchor Shackle - 3/8"

Here is a link to the 3/8" swivel: Chicago Hardware Jaw To Eye Swivel - 3/8"

Chicago Hardware manufactures USA made products. I've only anchored a few times with the new shackle/swivel, so hard to tell how well they hold up to corrosion, but so far look like new after a few anchorings. The 2,200 pound working load is sufficient for our boat in most all weather conditions, which is about half the breaking load.

The original 3/8' shackle/swivel show no signs of stress, even after weathering some pretty strong winds at anchor; just normal wear and some surface corrosion after almost twenty years of use.

Defender did give me credit for the swivel that I returned. Nice company to do business with.

The shackle/swivel below still had some service life, but opted to replace. The pin that connects to the chain link had the most wear, albeit very little, but felt it was time to replace.

You can see that the swivel pin is somewhat worn from long term use. Although it has the appearance of corrosion, most of it is superficial.

capta · May 4, 2021

In the first place, the swivel is improperly attached to the anchor. There should be a bow shackle that connects the swivel to the anchor, with the pin through the anchor. That avoids any side load on the swivel, as the swivel slides along the bow shackle's bow.
I won't use a swivel because, as mentioned above they become the weak link in your anchor tackle, and really don't do all that much good. I will not combine SS with galvanized chain or shackles on my #1, but might use SS shackles on my #2, as it rarely is in the water long.

dlochner · May 5, 2021

Terry Cox said:
The shackle/swivel below still had some service life, but opted to replace. The pin that connects to the chain link had the most wear, albeit very little, but felt it was time to replace.

Wear on shackle pin can be deceptive. It takes surprisingly little wear to cause a large decrease in strength. Strength is more highly correlated to cross-sectional area than it is diameter. Last year I wrote about this in Good Old Boat Magazine. The discussion about wear, pin diameter and strength is at the end of the article.

The Grind | Good Old Boat

goodoldboat.com

Terry Cox · May 5, 2021

Thanks for the article, Dave. Interesting read. Must pay more attention to these devices and will in preparation for our summer cruising. I have inspected our mainsheet traveler car and shackles in the past, as well as keeping them secured when not in use, but with less a trained eye than your article suggests. I do the same with our standing rigging and such.

Davidasailor26 · May 5, 2021

Terry Cox said:
The shackle/swivel below still had some service life, but opted to replace. The pin that connects to the chain link had the most wear, albeit very little, but felt it was time to replace.

You can see that the swivel pin is somewhat worn from long term use. Although it has the appearance of corrosion, most of it is superficial.

My yacht club used that style swivel on its three racing marks last year. After about 6 months into the season two of the marks were seen floating away. We took out the third one and found this -

Upon closer inspection, the cotter pin retaining the clevis pin was a bit rusty.

We suspect on the other two marks failed, dropping the anchor chain.

We replaced the chain and anchors, but decided to skip the swivels.

What Anchor Shackle to get? Galvanized anchor shackle with G4 chain and stainless swivel

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