Do you want to be informed on new Posts on this Thread? (members only)

S&S Swan General - Bolt for sounding fuel tanks
04 June 2022 - 18:08
Join Date: 13 April 2020
Posts: 10

Bolt for sounding fuel tanks


I am looking for a spare or two of the flange bolts that unscrew to sound the diesel tanks on a Swan 47 (104L). I have been told that they are M16 x 1.5. This appears to be a difficult part to source. I am in California (USA).

Any ideas?

05 June 2022 - 05:10
Join Date: 05 August 2010
Posts: 164

I haven't heard of a bolt of only 1.5 mm length, most are longer (16 mm is the diameter).But if I don't misunderstand, the solution might be easier: any M 16 will do for the sounding hole.
I assume you mean the center bolt in the inspection cover. There is a lot of space underneath; after all, the sounding stick should be able to pass. Make sure that it is actually an M16 that you need, and take a short one - the longer they are, the more turns are needed before and after sounding. I'll keep my fingers crossed that you will be able to find a metric bolt in the US; if not, we'll find a solution.

Best regards,


05 June 2022 - 10:49
Join Date: 17 July 2020
Posts: 104

M16 is 16x1.5mm… this is not the lengh but the screw dimension, not difficult to find in EU website…


06 June 2022 - 03:15
Join Date: 13 April 2020
Posts: 10

The flange bolt is 16 mm in diameter with a 1.5mm thread pitch. The length is about 20mm.

08 June 2022 - 19:30
Join Date: 01 March 2007
Posts: 147

When I lost mine, I asked my local fabricator to make one up which he did, but it was not a standard metric size, ( cant remember the actual thread size he used) but his best effort was a tight fitting bolt which does not leak. I think it must have been an old imperial thread. Of course I found the original when I came to remove the tank and find it beneath!


Sarabande 47/029

  • Threads : 1715
  • Posts : 10272
  • Members: 823
  • Online Members: 0