How to go about Bending this God forsaken 316l chainplate

[montenido]

I read somewhere that filling the pipe with sand before bending makes it less likely to crack or crimp.

Cheers, Bill

[OS2Dude]

Do you have a fixed vice? Perhaps you could put it in and use a pipe for leverage to bend it?

[foufou]

I just bent a chain plate same dimensions as yours. What Dave s said. Short end in a large vise and long lever or cheater pipe on the long part. Took some force but doable. Good luck.

[Eastward ho 24]

Got it !short end in a vice,pipe over the long end for leverage, put a little heat on it maybe 800degrees but I think that was a non factor.

And the sand in the pipe trick I've seen done

[oleman]

I would take it to a machine shop. They could have used an iron-worker to punch the holes and a hydraulic break to form the bar at a cost lower than the price of the bits you destroyed.
In the future use cobalt bits [in a drill press] on hard metals. On the cheap use a masonry bit.
Good luck with your project!

[hpeer]

Harbor Freight hydraulic conduit bender. Put a piece of wood on the center pin, use a hole saw to make a 1/2” Delancey hole for it to sit in. If you get fancy cut the wood on a bevel to match your bend. Then you can go slow and bend it easy. The bender is about $200. I made a bow pulpit railing last summer. It came out OK. Not like a professional job but you have to use your hands to “see” the difference. I just broke the radius up into 32 segments and made about a billion tiny, even bends. Took about 2 hours including all measuring practice on some similar size EMT to get the hang of it.

That’s a LOT tougher ban your project.

Then again ain't much a motivated man with a hammer and good vice can’t accomplish.

[ZULU40]

Originally Posted by Eastward ho 24

Made the rest of my chainplates with silicon bronze and boy do I love working with that stuff! Time constraints and lack of material I had to regrettably make my back stay out of 316l. it’s gonna have to go through my caprail and mount to the inside of the stern due to my placards ( nameplates.?) . I weld stainless pipes, and work with it quite often ( uaslly 308 or 410 or 309) I’m aware of heating it to much and cooking the chrome out and weakening it and causeing it to rust. To be honest as much ss I’ve welded cut and fabricated it, I’ve never had to bend it. So I’ve cut and drilled my piece and now I need to put maybe a 45 or 30 degree bend on it. Don’t have time to get it to a shop so I’m gonna clamp it down and beat it with a an 8 pound hammer.I've Got an acetylene speeed torch and a little map gas torch too. I’m worried it’s gonna crack if I just bend it. Has anyone bent. A piece or 3/8 316l flat bar it’s 2”x 3/8” by beating it? Should I put some heat on it? Or just beat it over?

take it to a boilermaker or job lot steel shop and get it pressed
3 minute job tops. And it will be accurate ... or

Hold it somehow be it vice. or in the frame of a shed (steel) or a tube in a trailer etc. The take a length of pipe or tube, insert the appropriate distance and bend the end over. U can do same if u have a giant shifting spanner or stilson, or make a plate dog with a welder out of plate.

Remember SS is around twice the strength of mild steel, so the equivalent of 3/4" steel. Save some worry go to a steel fabrication job shop.

[Dave22q]

A minor job like this will be a minimum charge vat a decent metal shop. Using a break makes this a 5 minute job. My local shop would charge a minimum $45 and would include any holes required. Sometimes DIY is neither smart nor economic.

[Cheechako]

DO NOT use a torch. You can bend it without heat. That's 3/8"? For some reason it doesnt look it. anyway, as mentioned by others , put the short end in a vice and bend holding the long end. If it's 3/8 it will take some effort and the vice will need to mounted on something heavy and secure! The bend will have a pretty good radius doing it this way, Hopefully you can live with that radius in the bend, but it wont crack any way you do it. The other option is most any auto shop has a hand hydraulic arbor press, they can bend it quick and easy if you can get them to do it.

[gbowen]

You can cut grooves with a cutting wheel on a small grinder and then weld the grooves after bending. I bought a plasma cutter instead of a gas outfit so needed to get a more creative in my metal working and used this technique as my last resort. Seems to work though!

gbowen

[Rick Williams]

I just redid all our chain plates and we did them all with a very inexpensive press from Harbor freight. It's a simple metal frame with a bottle jack attached. It's cheap enough that you give it away when you're done and so much easier than a vise.

[Mike Banks]

If it were I--I would cut it and weld it and put in a brace (or two--one each side of the strap) on the inside (or outside) of the corner if the bend has to fit around a permanent fixture. I do not like anything closely touching stainless steel in a saltwater environment. Crevice corrosion is often hard to detect.

Have you considered using twin back stays to dodge the extra stuff you have there? They can be mounted diagonally each side of the stern and be bolted to strengthening mounted inside the hull. Where they join the mast you will need to have a triangular plate to take the two stays, or a short length of chain to each stay with a common shackle to the mast fitting.

[Cheechako]

Welding something as simple as that is crazy. The act of welding will create a condition that invites corrosion... unless you Solution Heat Treat it afterwards returning the micro structure to the pre welded condition. Just sayin'.

[groundtackle]

Without the correct tools or a strong vise...For one bend like that I'd set it up properly on the floor on hardwood or aluminum blocks so it doesn't mar. Just a little separation between those blocks like 1/2" to get a crisp bend. Find pushing die like some shaft, maybe 1/2 - 3/4", lay it parallel on the bend line and tape it there with duct tape. Grab your big sledge hammer and hit it square. Its softer than you think. Tape the whole thing together to stop things flying if you miss...or don't miss.
No heat required, have a look at a formed stainless turnbuckle toggle that goes on that chainplate. There are acceptable min bend radius specs that materials have before deformation/tearing, your not even close to an issue.
Then cheers to your dockside metal fab afterward.
Chris

[fabricator-ken]

I make and bend ss all the time. If your chain plate is made from flat bar it will be very hard or cut out of plate easier. Cold or hot bending either way should not be a problem. 30 degree bend easy. If you are concerned about excessive heat passivate it after before polishing. eg you apply pickeling gel or paste to the surface. let it work for ten minutes or so . Completely wash off and polish. When drilling ss start with a small bit and work up.Slow speed lots of preasure. Coolant oil will assist. Don't fret take it easy.