Stainless Steel Chainplate Source

Looking to source some chainplates. I’m new to this. Is this something I can order off the shelf or do I need to send/take my old ones in as a template. Who here has had to replace any chainplates? Who supplied the original chainplates to SLM?


Ben: Hi!

Supplier of the chainplates (and gammon iron, cranse iron, and various tangs) for BCC28-116 was:

Marine Machine and Manufacturing (otherwise known as MarMachine)
719 Ohms Way
Costa Mesa CA 92627
Telephone: (949) 645 7601
Mobile phone: (949) 294 2171 (Mr Leigh Knudson)

Read the note on the Marmachine website about the consequences of the continuing closure of quality boatbuilders in Southern California. And also check out the gear that Leigh is selling on e-Bay (such as Machinist’s tool box made in oak).




Thanks for the info, I contacted Leigh, he says he doesn’t have any templates and also stated that he wasn’t the last manufacturer to make the chainplates for SLM. I wasn’t able to find that note about quality boat yards closing…


Cape George Marine works can supply probably via Port Townsend foundry.

tnx, will def check out!

According to data I got from Sumio, these items were supplied by “MarMarine” as opposed to “MarMachine”, but that could be an error, as I can’t find any trace of them on the web:

Chain Plates
Boomkin Plates
Boomkin Stay Tangs
Whisker Stay Tangs
Crance Iron
Gammon Iron W/rollrs
Hook, Anchor
Roller, Stern Anchor
Bowsprit Base Socket
Mast Base, Alum 7 X 14
Washers, Sq. 1 7/8
Bobstay Tang
Chain Plates
Boomkin Plates
Boomkin Stay Tangs
Whisker Stay Tangs
Gammon Iron
Hatch, Aft Bracket
Anti-Chafe Plate

I would imagine, however, That Port Townsend Foundry (Who have suplied chainplates to other BCC users) is the best avenue. They will probably not be predrilled,


Hi Ben, I had Port Towsend Foundry, Pete Langly, cast Manganese Bronze midship, lower bobstay, and boomkin chainplates, for my BCC 072 .

It sounds to me that you would like to use ss to replace your existing ss chainplates. The advantage of ss over cast bronze from Pete, will be weight savings.

Pete’s castings are larger than the ss ones, thicker, and heavier, and of course will need to be drilled, which needs careful attention to drill them, from the inside, while clamped in place.

If I had to do it again, for the midship chainplates, I would use aluminum nickel bronze plate, and bend them to copy your existing ss plates.

I would perfer the P T Foundry to cast the, exterior mounted lower bobstay chainplate in Aluminum - Nickel bronze, instead of Manganese Bronze .

It has been long known that P T Foundry, is slow to deliver on orders, which causes some owners problems.

I don’t know, but I suspect that Talesin midship chainplates, that were cast in aluminum nickel bronze, would not quite be the same curvature as your Morse BCC ones .

The boomkin chainplates from Pete are fine, as is, but are not drilled either.

If I were to want to replace my midship chainplates with ss, I would not choose 304L or 316L , but instead chose a ss alloy more rich in chrome and nickel, like the alloy which is used in ss rod rigging, or Aquamet (sp-?) 22 prop shaft alloy.

Most of my sources say, reguardless of which ever ss alloy you choose, polish them to mirror finish, inside, outside, and on the edges too.

Don’t forget to champhor all the holes in the f/g and ss too.

Good luck, do it right once, and you won’t have to re-do it again.

Douglas, BCC Calliste


Your suggestion to use aluminum-nickel bronze is well founded. We had a couple of bumpkin tangs made from this alloy for our last boat. The tangs never showed any signs of corrosion even though they were partially immersed in sea water. The material is very hard, hence good drill bits, such as colbalt bits, are recommended.


Aluminum Bronzes -


Aluminum bronzes are used for their combination of high strength, excellent corrosion and wear resistance. Aluminum bronze alloys typically contain 9-12% aluminum and up to 6% iron and nickel. Alloys in these composition limits are hardened by a combination of solid solution strengthening, cold work, and precipitation of an iron rich phase. High aluminum alloys are quenched and tempered. Aluminum bronzes are used in marine hardware, shafts and pump and valve components for handling seawater, sour mine waters, nonoxidizing acids, and industrial process fluids. They are also used in applications such as heavy duty sleeve bearings, and machine tool ways. They are designated by UNS C60800 through C64210. Aluminum bronze castings have exceptional corrosion resistance, high strength, toughness and wear resistance and good casting and welding characteristics. Aluminum bronze castings are designated as UNS C95200 to C95900

Great info guys, tnx… learning lots of new stuff here :slight_smile: