keel bolt torque specification

[sens]

How do you specify torque on keel bolts?

[yokebutt]

Sens,

A basic engineering text-book is probably all you need.

Yoke.

[Bergalia]

It depends on the material; the diameter, and thread. The bolt retailer should be able to specify - if not - shop elsewhere.

[marshmat]

If only there were such a thing as a "basic engineering text-book" I'm sick of buying $600 worth of the things each term only to find half of them are useless....

[astevo]

i think he is talking a basic engineering book like a RL Norton, mechanical engineering design, or j e shigley, machine component design, i picked up a copy of shigley for 50$ from people at uni as they graduate.
there are specific formula and processes for calculating the pre loads on bolted joints, nothing approximate or dodgy guess work

[dougfrolich]

Basic Formula for starters;

Target Torque ft.lbs. = (Nut Factor x Nominal Dia. Inches x (.75 x yield strength )) /12

Nut factor approx. = .2 for plain, .22 for plated, .1 for lubed up

[Bergalia]

Originally Posted by dougfrolich

Basic Formula for starters;

Target Torque ft.lbs. = (Nut Factor x Nominal Dia. Inches x (.75 x yield strength )) /12

Nut factor approx. = .2 for plain, .22 for plated, .1 for lubed up

I was going to mention that next....
Excellent response Dougfrolich - that's what this forum is all about. On behalf of Sens and all the rest of us 'boaties' - many thanks