Don't know, but they said the 30% extra was to overcome the friction between their two washers and produce the same initial strain in the bolt as the others. Since all the curves start at the same load point, that would appear to be true, but it could be marketing sleight of hand. It sure looks easier to use than wire though.
While I have not used those in the crownwheel application, I do use them particularly around alloy trans housings, exhaust headers, drysump pump mounts etc, have yet to see anything come loose where we use them. Only thing that is a little disconcerting is the breakaway torque reqd when removing them to service a part.
Thanks, and couldn't be at a better place to get them from. They also have them in stainless as well as a couple of plating. 3/8" zinc-steel looked about $11usd for 25, Stainless were about a $1 each. I didn't look but would be cool if they had a US and Metric assortments.
[EDIT] - It seems they have assortments in US sizes at McMaster
From the movie the two bolts that was locked with safety wire , had nothing with locking to do , You must use safetywire the right way if you want to lock a bolt/nut. I use locktite for some bolts/nuts , from my experience in aircraft building(experimental) I think I'll stick to wire for things that it is important to trust.
I have checked the web and the demonstration.
To me it sounds like it is not a joke. Next Tuesday the Italian importer is coming to meet me with some samples and a concrete demonstration.
If the describtion is completely true and there are not influencing parameters that ill never become pubblics, this is the best invention in terms of trustability of bolting necessities.
Will do some tests and will come back to you by september about it.
In theory it works perfectly.
I have used them on my Rover V8 race motor which was continually loosening off the rocker cover screws. Fitted Nordlocks and never had another problem. Didn't know about over torquing them 30% though, they were just tightened up the same as before. Not sure that I'd be keen to over torque into alloy though.
I have got them in my hands and I will definetly use them in someareas of my transmissions. They are the best when they work on surfaces which are not hardened. If the opposite material is harder then 52 HRC they do not work anymore.
Who is using Nord-Lock washers shall have a basic knowledge in terms of steels and hardened steels. But generally they are the best on the market. As it always happen, the best things have some restrictions. Anyway better then many restrictions.
I used them years ago in a mining application that had to withstand high vibration and high shock. Never experienced a failure. They were also used on a component that required periodic maintenance and were reused.