Cutting Stainless Steel

[ggray]

I am having my ss anchor tipper modified. The side plates (at least 1/8 inch thick) will need to be cut.

What is the preferred tool to do this without possibly overheating the ss and discoloring it ? The ss is now polished, and I'd like to return it to the same appearance. The shop plans to use a cut off saw that I believe utilizes a grinding wheel. They said it would not get the metal as hot as a plasma torch which, it sounded like, they had as well.

Before they get started, I'd like an objective opinion as to whether this is the way to cut it.

[Sailmonkey]

If they go slow it should be fine, if they plow through it it will get hot. The plasma is not the way to avoid discolored stainless.

[Sailndive345]

Originally Posted by ggray

I am having my ss anchor tipper modified. The side plates (at least 1/8 inch thick) will need to be cut.

What is the preferred tool to do this without possibly overheating the ss and discoloring it ? The ss is now polished, and I'd like to return it to the same appearance. The shop plans to use a cut off saw that I believe utilizes a grinding wheel. They said it would not get the metal as hot as a plasma torch which, it sounded like, they had as well.

Before they get started, I'd like an objective opinion as to whether this is the way to cut it.

I had to cut holes into and trim a 1.25" S/S extrusion in multiple places - used a Dremmel tool with reinforced cutting disks followed by the sanding attachment - it worked very well. The grinding wheel should work the same I'd guess.

As far as the welding gear goes, I'd recommend staying away from it. My stern rail has a couple of welds on it - discolored and regularly gets surface rust - The PO had this done and it may have been when they were installing the dinghy davits. In any case, it didn't work as well.

Good luck!

Sailndive

[anjou]

Ask the shop to try a few different methods with some scrap steel before you decide

[forsailbyowner]

If you use cutoff wheel I'd recommend one of the very thin ones on a 4" grinder and make successive quick shallow passes instead of one. That will keep the heat down. Bandsaw might be best way to keep it real cool.

[FSMike]

Here I go being ignorant again.
What's an anchor tipper?

[James S]

Originally Posted by FSMike

Here I go being ignorant again.
What's an anchor tipper?

Me too?

[Sailndive345]

Could it be the bow (anchor) roller?

[Machinist Mark]

I figured there would eventually be a post where I could make a small contribution. Been a longtime lurker and very appreciative of all I've learned by reviewing various threads. This question happens to be right down my wheelhouse as a cutting tool metalworking guy.

The stainless is most likely going to be 300 series - austenitic stainless steel to use the metallurgical family name. You can easily confirm this by seeing if a magnet will stick to it. It likely won't - which means it indeed is austenitic. Another giveaway is a more golden hue instead of a grayish look like say silverware. This type of stainless workhardens quite easily when cut (due to high nickel content). Often this leads to more of a rubbing action during the cutting process which can cause the burned discoloration noted above.

Best way to cut it to avoid discoloration: Carbide is ideal. High Speed Steel with added cobalt is the second choice. An abrasive cutoff wheel can be used, but would not be my first choice. A high speed steel band saw blade could also be used, but that would not be the easiest and most fool proof method. One potential problem is that you will have no way of knowing what is going on in the area where you are cutting. This "tipper" was either machined, or forged, or cast by who knows and how, and the surface could already be work hardened. Thus, you go to cut it and there could be a surprise.

So - assuming you are really really keen on keeping the cosmetics just right, ask the machine shop to mill off the side plates with a solid carbide endmill. They may tell you that's overkill, which it very well might be (not knowing what an Anchor Tipper is, nor how these side plates are located on it), but simply say "humor me" and they will chuckle, give it to "Good Ole Joe" on the milling machine, and 15 or 20 minutes later you should have your Tipper back looking the way you want it. Figure on $70 an hour plus maybe some paperwork / admin fee. So, say $30.00 would be fair (again - a professional guess here as I haven't seen the part).

There are some machine shops in your area that I've seen post on these boards - so I would not be surprised if you find someone else pops in on this thread.

[beneteau-500]

having worked in the gas industry for yrs after we either cut or welded stainless steel we always pickled and pasted it then polished it and it never discoloured or rusted

[thinwater]

I have cut 1/8" to 1/4" SS with these many times. No heating to speak of, very easy. Any contractor should have one. A standard fine (~ 18-24 tpi) blade will work.

Mark had good points, all. But I think the HS band saw will be fine for this. They are generally simply bent plate.

[paradix]

Originally Posted by FSMike

Here I go being ignorant again.
What's an anchor tipper?

Yes bow roller.

Cray (lobster) boats here have a similar fitting for pulling up the cray pots - and it's usually called a "pot tipper". Does exactly the same thing - allows you to raise the pot/anchor and when it gets to the deck it tips!

Have only rarely heard the anchor roller being called a tipper too, but it definitely happens...

[cdennyb]

Milling machine is my first choice,
Porta-Band is my second.

[S/V Antares]

I believe the "tipper" is an articulated bow roller. Bent plate so not so hard to cut / Drill with the methods mentioned above

[ggray]

Sorry, I didn't mean to confuse anyone using the terminology of the boat builder ! Sailndive and paradix have it right. I see West Marine calls it a pivoting anchor roller.

Thanks for all the guidance. I had suggested that they try cutting first on the part to be removed, but now I have some educated suggestions to offer.

It is fabricated of ss plates welded together; clearly the welding, if done properly, won't cause a problem.