Stretching chain

[winsbury]

So the saga of getting my windlass fully rigged up moves onto a new phase: a chain problem. The shackle holding the anchor to the chain was catching in the bow roller preventing a tidy loading of the anchor back onto the bow fitting. So, I have bought one of those pretty two-way swivels that have flush allen key fittings. Its arrived today and very shiny it is too.

BUT ...

the 11mm diameter pin turns out to have an M11 thread which actually makes it 11.8mm diameter at its widest. The hole in the end link of my Din 766A 8mm chain is 11.1mm at its widest point. So, the question is how to get the pin through the chain ? Please don't suggest going for a smaller swivel as there isnt one that will fit my CQR without changing down to a smaller anchor.

Options I have thought of are:

1. heat and hammer the final link to a more round shape to open up the interior space
2. as per option 1 but using a cold 2Tonne press instead (not sure if it would be powerful enough)
3. force the 316 screw thread though the link and hopefully it will cut its way into the zinc and steel of the link
4. Drill out the link
5. Force a conical spreader of some sort onto the link to open it out a little.
6. File the thread on the bolt flat on one or possibly two sides

We are only talking here of getting .8mm extra space to make this work.

So, any ideas or comments of the best method without weakening the chain and making sure the final result will be secure ?

 

[winsbury]

Sorry folks, just realised I was having a dumb moment - a 10mm flush pin shackle will solve this.

 

[vyv_cox]

Squeezing the chain a little in the vice will do no harm whatsoever, put the ends between the jaws. Heating it is completely unnecessary, Grade 30 chain is extremely ductile and soft, it will deform readily. The action of bending it, although in this case the requirement is minute, will cause some work hardening which, contrary to the opinions of many posters, will actually strengthen it. See my photos at the bottom of this page http://coxengineering.sharepoint.com/Pages/Chaindefinitions.aspx I easily bent 8 mm links using an adjustable spanner.

 

[winsbury]

Squeezing the chain a little in the vice will do no harm whatsoever, put the ends between the jaws. Heating it is completely unnecessary, Grade 30 chain is extremely ductile and soft, it will deform readily. The action of bending it, although in this case the requirement is minute, will cause some work hardening which, contrary to the opinions of many posters, will actually strengthen it. See my photos at the bottom of this page http://coxengineering.sharepoint.com/Pages/Chaindefinitions.aspx I easily bent 8 mm links using an adjustable spanner.

Before my epiphany I did try in a press in the engineering shop over the way and you're right, it deformed relatively easily but the second link in the chain then became the issue as it prevented the first link going far enough into the jaws of the swivel for the threaded pin to line up correctly. Hence a shackle seems to be the only solution.

 

[cliff]

So the saga of getting my windlass fully rigged up moves onto a new phase: a chain problem. The shackle holding the anchor to the chain was catching in the bow roller preventing a tidy loading of the anchor back onto the bow fitting. So, I have bought one of those pretty two-way swivels that have flush allen key fittings. Its arrived today and very shiny it is too.

BUT ...

the 11mm diameter pin turns out to have an M11 thread which actually makes it 11.8mm diameter at its widest. The hole in the end link of my Din 766A 8mm chain is 11.1mm at its widest point. So, the question is how to get the pin through the chain ? Please don't suggest going for a smaller swivel as there isnt one that will fit my CQR without changing down to a smaller anchor.

Options I have thought of are:

1. heat and hammer the final link to a more round shape to open up the interior space
2. as per option 1 but using a cold 2Tonne press instead (not sure if it would be powerful enough)
3. force the 316 screw thread though the link and hopefully it will cut its way into the zinc and steel of the link
4. Drill out the link
5. Force a conical spreader of some sort onto the link to open it out a little.
6. File the thread on the bolt flat on one or possibly two sides

We are only talking here of getting .8mm extra space to make this work.

So, any ideas or comments of the best method without weakening the chain and making sure the final result will be secure ?

'nuff said...