Locking hardware (nuts and bolts)

Well...

I had a bit of an "incident" over the weekend at the Challenge.

I need locking hardware, or something guaranteed to not loosen or back out. Studs are not an option.

Sooo... nuts and bolts.

Learn me some!

Depends on the issue you had. Fess up.

Loctite can help.

His turbo fell off.

amg_rx7 wrote: Depends on the issue you had. Fess up. Loctite can help.

Turbo pretty much fell off. I'm pretty sure it actually started on the drive down there, and wasn't helping the autox performance either, as the spool gets really weird.

I'm looking hopefully for a non-loctite solution, if possible.

Stage 8 fastners rock. http://www.stage8.com/

44Dwarf wrote: Stage 8 fastners rock. http://www.stage8.com/

That was it... someone was telling me about those at the Challenge, i forget whom...

Question, though... Do i use locking bolts AND nuts with that stuff?

I'm currently using some Zinc'd Grade 8 5/16"-20 1.5" long bolts with nuts and lock washers.

There are some locknuts that lock on the threads and will not come off unless you destroy the threads of the bolt (forgot what they are called) or you could lock wire it.

93EXCivic wrote: There are some locknuts that lock on the threads and will not come off unless you destroy the threads of the bolt (forgot what they are called) or you could lock wire it.

I'm not real familiar with lock wiring, but isn't that what they commonly do on muscle cars' header bolts or something?

Safety wire? Doesn't that just make sure it doesn't come off completely? I need to make sure this stuff doesn't even back out an 1/8th of a turn.

In reply to 93EXCivic:

IIRC, those should have a recessed square or rectangle on an outside flat surface. We use them on our bean head's cutter bar. Work very well......I think nylock won't work with the heat involved here.

yamaha wrote: In reply to 93EXCivic: IIRC, those should have a recessed square or rectangle on an outside flat surface. We use them on our bean head's cutter bar. Work very well......I think nylock won't work with the heat involved here.

Nylock most certainly does not work. Been there, done that, got the t-shirt.

He's not talking about nylocks, though...

92CelicaHalfTrac wrote:

93EXCivic wrote: There are some locknuts that lock on the threads and will not come off unless you destroy the threads of the bolt (forgot what they are called) or you could lock wire it.

I'm not real familiar with lock wiring, but isn't that what they commonly do on muscle cars' header bolts or something? Safety wire? Doesn't that just make sure it doesn't come off completely? I need to make sure this stuff doesn't even back out an 1/8th of a turn.

No if not it is done right it should let it back off.

http://en.wikipedia.org/wiki/Safety_wire

http://www.mcmaster.com/#slotted-nuts/=jjpll7

Also I am not talking about Nylocks. I will ask the other mechanical engineer what those nuts are called when he gets in. He used a lot at NASA.

93EXCivic wrote:

92CelicaHalfTrac wrote:

93EXCivic wrote: There are some locknuts that lock on the threads and will not come off unless you destroy the threads of the bolt (forgot what they are called) or you could lock wire it.

I'm not real familiar with lock wiring, but isn't that what they commonly do on muscle cars' header bolts or something? Safety wire? Doesn't that just make sure it doesn't come off completely? I need to make sure this stuff doesn't even back out an 1/8th of a turn.

No if not it is done right it should let it back off. http://en.wikipedia.org/wiki/Safety_wire http://www.mcmaster.com/#slotted-nuts/=jjpll7 Also I am not talking about Nylocks. I will ask the other mechanical engineer what those nuts are called when he gets in. He used a lot at NASA.

Ah ok.... that looks interesting, but also potentially a PITA considering placement in this case. HRMMMM....

92CelicaHalfTrac wrote:

93EXCivic wrote:

92CelicaHalfTrac wrote:

93EXCivic wrote: There are some locknuts that lock on the threads and will not come off unless you destroy the threads of the bolt (forgot what they are called) or you could lock wire it.

I'm not real familiar with lock wiring, but isn't that what they commonly do on muscle cars' header bolts or something? Safety wire? Doesn't that just make sure it doesn't come off completely? I need to make sure this stuff doesn't even back out an 1/8th of a turn.

No if not it is done right it should let it back off. http://en.wikipedia.org/wiki/Safety_wire http://www.mcmaster.com/#slotted-nuts/=jjpll7 Also I am not talking about Nylocks. I will ask the other mechanical engineer what those nuts are called when he gets in. He used a lot at NASA.

Ah ok.... that looks interesting, but also potentially a PITA considering placement in this case. HRMMMM....

Yeah it wouldn't be fun at all. I think a lock nut of some kinda would be a better solution.

http://www.mcmaster.com/#hex-locknuts/=jjpny9

Here is McMaster Carr's selection of locknuts.

93EXCivic wrote: http://www.mcmaster.com/#hex-locknuts/=jjpny9 Here is McMaster Carr's selection of locknuts.

The Mil-Spec distorted thread lock nut look like your best choice in a lock nut.

Safety wire is a PITA to install but if done properly will insure that the nut cannot turn at all. My experience is that safety wire is better than any lock nut particularly where heat and vibration are involved.

The only problem with safety wire is you wont be able to stop playing with the cool pliers.

Hal wrote:

93EXCivic wrote: http://www.mcmaster.com/#hex-locknuts/=jjpny9 Here is McMaster Carr's selection of locknuts.

The Mil-Spec distorted thread lock nut look like your best choice in a lock nut. Safety wire is a PITA to install but if done properly will insure that the nut cannot turn at all. My experience is that safety wire is better than any lock nut particularly where heat and vibration are involved.

Unfortunately, i don't think safety wire is really an option here.

My question about the mil-spec distorted thread lock nut is temperature rated. Seems it's rated to 800 degrees. Suppose i need to get an infrared reading on my manifold.

Tab washers.

Deformed flange on nut.

Distorted-thread nuts come in many materials, with various temperature capabilities, some hotter than 800F. They are only good for a small # of cycles before you wear the threads on the bolt or stud, at which point both ends need replacing.

Welded nuts - spot weld to the flange.

Lock wire.

Nord-lock washers. These work great but can wear the washerface of the nut or bolt head with # of assy/disassy cycles.

The important part is the flange design - keep the load from cycling the fastener in a way which will cause it to lose preload.

for the Challenge budget, Stover nuts are a good solution--they are of the distorted thread type and available at most nut and bolt merchants.

Per

Per Schroeder wrote: for the Challenge budget, Stover nuts are a good solution--they are of the distorted thread type and available at most nut and bolt merchants. Per

Cool!

Think it would be a total waste of time to use those AND lock washers on the bolt end?

+1 for the distorted thread nuts. We use them at work (Home Depot tool rental) instead of nylocks for critical things. Ya know, like a 28 hp stump grinder with 9 lbs worth of blade teeth spinning at 5400 rpm. We prefer it if they don't vibrate off, go flying through the air, and embed themselves in the skull of a customer.

We replace them every rental, but I do find that two things happen; 1) the bolts also have to be replaced every 2-3 uses because the distorted thread chews them up, and 2) they seem to retain more thread grip if you install them by hand slowly instead of with an air ratchet or impact. Seems like the additional speed/friction tends to wear the threads making them grip less.

No amount of chemicals will help you. Loctite will work for a while but the super high heat will crystallize it. Powdered loctite won't help Nylocks will melt in seconds and then you just have a plain nut.

I also agree with MattGent; a properly torqued bolt in a well-designed flange shouldn't come lose.... but I understand your desire to slam dunk this one and never think about it again.

In a pinch, double nutting will work too.

(and yes, TWSS)

+1 for Nord Lock washers. I've done testing with them and they actually do work- it requires more torque to remove the fastener than you applied to it when you tightened it. They resist vibration loosening better than other types of locking fasteners, too. You don't just need a fastener that stays put, you need one that maintains clamping force. The Nord Locks will do that.

Not much I can recommend over that. Just make sure your fastener grade and torque, clamping load and thread lubrication calculations are accurate, and use the best torque wrench you can find. Always make sure your threads are spotless and perfect, and lubricated for optimal friction consistency.

-M.S. Mechanical Engineer

The joint between the exhaust manifold and the turbo on a Miata can get upwards of thousands of degrees during a track day. For that reason I'm familiar with this. I had to end up using Stage 8 locking nuts with iconel studs.

All from Flyin Miata. These studs. Deez nutz.

Worked great. My turbo didn't stretch the studs during track days after installing these. Then my car was run over by a bucket truck.

The Flexloc nuts work pretty well.

From a challenge perspective, holes are pretty cheap, so is a piece of wire.