Chain Plates
 

I am in the process of changing out my stainless steel chain plates and am considering C655 silicon bronze. I am thinking of buying mill C655 bar and drilling holes and polishing to make my chain plates. I would be using either silicon bronze nuts and bolts or 316 ss.

One thing that concerns me is the source of the silicon bronze- some Asian sources may be questionable as to quality and if it is truly C655 specifications.

Please comment and advise if this is a good idea.
Regards

Bother
 

Hello,
You are right, some Asian metals are not top-drawer. On the other hand, some are, But unless you know someone that you trust, who in turn knows and trusts others, and so on down the line, it is a crapshoot. But why buy Asian at all? Cost? If so, for whatever reason, your chances of getting good stuff are much better in this country. Think of it as paying a premium for quality.
Fair leads,
Brion Toss

Brion,
Thanks for reply. I would rather buy US made silicon bronze, but cannot find it. I have found some made in Germany, which I would expect to be of good quality. If I purchase, I will request mill data sheets to confirm quality.

This brings up some more questions. I was thinking of replacing my 316 Stainless chain plates with C655 Silicon Bronze. The Tensil and yield strengths, as well as hardness look to be nearly equal. Therefore I was thinking of making the silicon bronze chain plates the same size as my currently installed 316 stainless. Yet when I spoke with a rigger and a chain plate fabricator, they suggest making the silicon bronze chain plate bigger to account for elongation the material exhibits under stress. Could you comment on this?

Also, I am considering using Grade 5 Titanium, yet most of this material is made and and fabricated in China. I was concerned about the potential quality of the Titanium chain plate, but some articles about Titanium chain plates say this should not be a concern, as the material and fabrication are of good quality in China, as China supplies most of the Titanium material on the world markets. Please comment.

Regards

It depends
 

Hi again,
Check Skene's and you'll see that Silicon bronze and stainless chainplates are properly done with the same scantlings; Bronze is more ductile, but the offset in the direction of the load, plus metal thickness and width, compensate. Not ever a problem, as the rigger should know...
You might see if Port Townsend Foundry can supply you with the chainplates you need.
As for titanium, I have had mixed experiences with Chinese metal. It is all about the supplier.
Fair leads,
Brion Toss

Chainplates
 

Hi,
If you haven´t already solved your problem this may help. I also changed my chainplates from stainless, but to nickel aluminium bronze. Supplier is a UK company whose main customers are the aerospace industry ( http://www.cnalloys.co.uk/). I didn´t think to check the source of the raw material. Finding the appropriate bolts was a problem, as the existing holes in the bulkheads are metric, but that has now been solved too.
Regards,
Bill Attwood

Chainplates - why change from 316 stainless?
 

I was about to replace the chainplates on my S&S 34 with another set made of 316 stainless, but reading your post and the subsequent string has stayed my hand. What argues for changing from stainless — is it the shortcomings of 316 in this application or the advantages of other alloys?

Regards,
Jan Waldin

The main reason I was considering another material besides 316 stainless is to get away from the stress corrosion cracking problem. I am located in Hawaii and the salt air and tropical heat is a problem for stainless. I was considering either silicon bronze or titanium.

Silicon Bronze
 

Ahoy Storm ,,, the last Silicon Bronze plate stock , that I purchased was from Alaskan Copper and Brass : http://www.alascop.com/pdf/brbr/silicon_comm_sheet.pdf ,,,,,, they shipped that small order to me on Langkawi Island , Malaysia . The shipping cost just about the same as the metal , itself .

Since there is such a heavy presents of US Military in Hawaii ,,, you might even find some silicon bronze supply, there .

Douglas,
Thanks for reply. I am in contact with Alaskan Copper and Brass. Their fabrication shop can water jet cut from silicon bronze plate the size I need for my chain plates. This is great as I could not find silicon bronze flat bar that would meet my dimensions and I did not want to buy oversized bar and then have to mill or cut it down to size. Bronze plate is available in a lot morte thicknesses as compared to flat bar.
Regards