Destructive Lock Nuts Suck

Goose neck and straight pull trailers are required (DOT) to have safety chains. This one has 3/8 chains and screw couplers. The chains are kind of a pain and in the way in the bed of a truck on a goose neck. They can even knock loose the electrical plug from the receptacle if one is not careful. Interestingly a fifth wheel does not require safety chains. More interestingly a clear definition of fifth wheel varies or is unclear depending on where it is looked up. Even in legislative definitions. Many are written in a manner that could include goose neck hitches. Where it becomes even less clear as to what is and is not a "fifth wheel" is when looking up the legality of towing RV doubles from state to state.

Found this tidbit:

An-cor-lox nut has a ring of soft metal, such as soft steel or brass at the bottom of the nut which turns on freely until the nut strikes the part.

Found it: Page 74 of the following: .<chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/

No longer made. Company gone. Basically a soft copper washer that is squished into contact with the bolt thread.

I've also run into Spiralock, which looks quite interesting.

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Joe Gwinn

Can you get more of the nuts that failed, to test or as evidence?

That is an interesting design.

IMO the biggest problem these items are trying to solve is for any worker keeping a nut from coming loose.

Though I worked with guys who would keep that success rate very low😬

Can't beat "belt and suspenders" - but always MEDIUM thread lock - if I need to get out the torch to release the thread lock I mayas well burn the sucker off!!!

Never seen a Drake before - ompressive. Ever run into a Key-Lok? Equivalent to hitting the top thread with an arc welder. That sucker is NEVER coming off - even if you want it to!!!

I had a tent trailer jump off the ball once. Had good safety chains crossed under the hitch but the toung jack took the abuse. It had a rubber tire on it and by the time I got stopped it was worn to a cone shape after attempting to drag the trailer off to the curb. From then on I always BOLTED the hitch latch - using a nylock nut. Still don't know how the clevis pin got out or why the latch released - I'm CERTAIN I latched it - - - -

Isn't the difference the attatchment? Gooseneck uses a ball. (or possibly a pintle) while a "fifth wheel" uses a pin and latch on a "horseshoe plate"

Different animal. The LoxNut has a captive free spinning serrated lock washer/flange similar to a NordLock washer, with the bottom of the nut serrated similar to the top half of a NordLock. The Disc-Lock lockwasher has ramps instead of the serrations of a NordLock. Similar action but on a different scale The Norf-Lock actually only claims 120% removal torque, while the disc-lock claims

The Stover works good on Grade 8 bolts although it is designed for High Strength L9 fasteners.

Spiralock has gone out of fashion as they are a "single use" locknut if I remember correctly from my Fiat Allis days - both nut and bolt to be replaced at every use. Not an issue for NASA as NO bolt gets re-used - - - but a pain when repairing a loader/backhoe in mud up to your ankles- head first!!! Their Key-Lock thread inserts work pretty good - never had one come out with the bolt/stud unlike HeliCoil.

I worked with one guy who's method was tighten until it breaks and back it off 1/8th of a turn. He could snap a 1 1/2 inch grade 8 bolt. (with a torque multiplier and johnson bar, but still!!!) The torque spec was something like 3600 ft lb so he had to be putting over 4000 ft lb to them - - - - -

Good point, although the nuts are pretty cheap, so one can afford to just replace them. The U-straps may also need to be replaced?

And you don't need to replace the thread insert after one use?

Joe Gwinn

Heart stopping to be sure.

I'm unclear as to what exactly came loose and then happened.

Joe Gwinn

I looked at the page and it reminded me of the Dardelet thread shown in Machinery's Handbook, the 21st edition at least which I have. I often wonder if Ford used that or similar on the crossflow rocker arm adjusters as the threads were self locking, no locknut.

That is the practical definition and perhaps the "dictionary" definition, but in the real world you have to deal with the legal definition. Remember the law says a tomato is a vegetable even though taxonomically its a fruit,

I had not heard of the Dardelet thread, but it is the same idea as Spiralock. Not made any more, it seems.

Dardelet's US patents are US 2,091,788 and US 1,657,244.

I ran into yet another locknut contender:

Security Locknut, which originated in the railroad industry a century ago, for use on such things are the assemblies that get the full steel-on-steel impact loads. In this case, "security" means against vibration, not thievery. There is just one supplier, but they are not terribly expensive.

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The relevant patents are US 1,166,203 and US 1,400,154.

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Joe Gwinn

They have a bit of give to them - which might help - but generally you don't count on a thread insert to be a lock-nut - although they are advertized and sold as .

The hitch unlatched from the ball. For that to happen the dafety had to release - and it was SUPPOSED to be secured with a latch-pin. When it jumped off the ball it was suspended on the crossed safety chains but the toung jack wheel, which was pointing slightly to the right, touched the ground and tried to stear the trailer to the curb and the pavement acted like a grinder and "machined" the tire into a cone. After that I ALWAYS double check the hitch and make sure everything is secured before starting out - and at every stop.

Looks like a similar action as the FujiLok

Ahh. That makes sense. This story is one of the standard arguments for the pintle hitch over any ball hitch.

Joe Gwinn