Chainplate Design

[BillShuman]

I am having new chainplates made for my Bayfield 40. On the old ones, the pin hole is obviously too close to the end of the chainplate. What is the rule of thumb for the amount of material between the hole and the edge of the chainplate? They are being made of 3/8" thick 316L. The pins are 1/2 and 5/8 inch.

Also, the old chainplates (which are attached to perpendicular FG knees) just used 3/8" bolts with washers. There are six bolts per chainplate. Do I need to use backing plates in this application or are washers adequate? Thanks.

-Bill

[Douglas]

Ahoy Bill , Yes , there are engineering guide lines, as to the recommended "shoulder area", on the chainplates,,, around the toggle pin holes.

I guess you would first check the toggle pin hole clearance, on the toggles you plan to use.

Way back when , Bruce Bingham, wrote a book on ferro-cement sailboat construction, which had an illustrated table guide line, that you could apply to your application, suggesting the necessary "shoulder area" .

There are other books that contain these recommended guide lines, as well, maybe even a book written by Brion Toss !

Sorry , but my memory escapes me , but your question is a v good one, and does need to be considered when fabricating new chainplates or link plates.