Torque required for keel nuts. Hunter 376

Jul 29, 2013
10
Hunter Hunter 376 Guayama
I own a Hunter37 1997. I am replacing keel nuts. What is the torque required? Thanks
 
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
The attached table provides guidance on torque based in bolt diameter derived from information in Table A7 from ISO/DIS 12215‐9.2. I would not hesitate contacting a sailboat mechanical contractor for consultation.
 

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Jan 4, 2006
7,274
Hunter 310 West Vancouver, B.C.
I would not hesitate contacting a sailboat mechanical contractor for consultation.
That would not be a good idea here in Vancouver. From what I've seen over the years, one could expect anything between hand tight and snapped bolts.

This is a copy of an .XLS file from Hunter a few years ago. I could not post here as an .XLS so copied it as a .JPG:

Hunter Keel Bolt Torques.jpg


Their numbers correspond to the maximum recommended torque for SS threads.

The ISO/DIS 12215‐9.2 numbers look like they are incorporating some additional factor of safety, perhaps in consideration of the FG contruction of the vessel.

I was forced to have my boat surveyed last summer (insurance) and the surveyor wanted me to demonstrate to him that my bolts were torqued (as a minimum) to the max. as shown by Hunter.

Keel Bolt Socket 2.jpg

I'm open to other thoughts here. Anyone else had a survey done recently that included keel bolt torques ?
 
Last edited:
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
Ralph, Sorry to hear that. Never had that experience in the San Francisco Bay.
 
Jan 4, 2006
7,274
Hunter 310 West Vancouver, B.C.
Never had that experience in the San Francisco Bay.
Maybe it's just your clean living down there that ensures good boat service.

Up here, it's pretty much the wild, wild, west when it comes to boat repairs. I do all the work on my boat just because I enjoy doing it. Over the years I've heard more and more stories about "professional" repairs and many of them are shocking. Makes me just that much happier that I do it all myself.

Do you have any in depth knowledge of ISO/DIS 12215‐9.2 re applied torque ?
 
Feb 21, 2013
4,638
Hunter 46 Point Richmond, CA
............Do you have any in depth knowledge of ISO/DIS 12215‐9.2 re applied torque ?

 
Jan 4, 2006
7,274
Hunter 310 West Vancouver, B.C.
Just curious, but not curious enough to buy the ISO standard. Just wondered why the ISO/DIS 12215‐9.2 standard for keel bolt torques is roughly 1/2 of the Hunter specs which are simply the max. allowable torque.
 
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