All About Nuts and Bolts

[RichardNew]

Here's my latest blog post. It's all about fasteners. Enjoy


Richard Newton
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[motogman]

Richard... I read your blog and appreciate your comments and the content. Bolted joints is a science that is to some degree being lost but is so fundamental to much of engineering.

I have some comments (both technical and editorial) that I would be happy to send me if you PM me with an email address.

[ClickClickBoom]

How about an analysis of Nord-Lock vs Schnorr washers?

[RichardNew]

Now that's a topic. Anyone?

Richard Newton

[jhlasserre]

I learned some good stuff there. I am amazed that they don't come loose. Is the spring/clamping action the only thing preventing a nut from coming loose over time?

[hcoles]

How's this for a fastener topic?
Use of Nyloc fasteners, e.g. what is the advantage of the nylon, if properly installed does the nylon keep the fastener from coming loose or just keep them on the bolt so they doesn't come completely off or lost? Think of the Reno incident more than one year ago. I haven't read that the final set of findings are out regarding why the Nyloc(s) came loose.

[RichardNew]

It's my understanding that the nylon keeps the nut from loosening under vibration. I'm not certain of that though. So much to learn - so little time.

Richard

[hcoles]

Originally Posted by RichardNew

It's my understanding that the nylon keeps the nut from loosening under vibration. I'm not certain of that though. So much to learn - so little time.

Richard

Some Pelican out there has deeper knowledge, many fastener (nut) applications involve vibration and don't use prevailing or nyloc approach. People use Nylocs and may feel they are getting some sort of insurance, but maybe in some applications no significant benefit is provided.

[ClickClickBoom]

Originally Posted by hcoles

Some Pelican out there has deeper knowledge, many fastener (nut) applications involve vibration and don't use prevailing or nyloc approach. People use Nylocs and may feel they are getting some sort of insurance, but maybe in some applications no significant benefit is provided.

Hey,
I posted this over on the Rennsport site:

Multifunctional wedge-locking solution from the Nord-Lock Group ... e-locking/

Watch the video!

Fastener security is my obsession for 2 more days, last week it was lasers, week before that it was fusion via the NIF, unfortunately my attention span is shorter than my dogs, oh well.

NIF= https://lasers.llnl.gov/

[vash]

when we build steel bridges. there is a week put aside we call "rocap hell"..we have to determine what torque is needed for all the batches of fasteners. it is horrific, but you learn. you love it for about an hour..then you want to find the next guy to give the clipboard to.

nice blog!

[ClickClickBoom]

Ok,
I just spent the last 40 minutes talking to an engineer at Nord-Lock. I described the CV bolting situation and process in detail from materials and coatings, the NL8 was confirmed to be the most appropriate Nord-Lock available for that application. He did think that the 33LBFT torque spec was danger close to the ultimate yield for the 12.9 spec bolt, he said it was right at the upper end of the torque range. This tells me that when Porsche designed the joint and bolt application they determined that it was right at design limits. The 100MM CV w/8mm bolts was a bean counter input(I hate those guys), and the engineers were working at the limit.
We were discussing the deformation process, he stated that the deformation occurred mostly during the first 12 hours after bolting and torquing. It seems like torquing after 2-300 miles is not only unnecessary but risks driving an under torqued joint. So I think, bolt torque, then next day retorque and the joint is properly reset! He also stated that the Nord-Lock is safe with lube and this lowers the potential torque value he recommended a 10% reduction in torque based on lubrication and the zinc coating on the boot cap.
I will be receiving a sample quantity of the new NLX series in the 8MM range. After discussion with him about the virtues of the Nord-Lock vs the Schnorr, I was impressed that he thought highly of the Schnorr system, but favored the Nord-Locks more recent improvements.
I do have a selection of NL6,8,10s thanks to eBay as well as a bunch of other hardware to boot!
eric

[RichardNew]

Here's a picture of the Nord-Lock

Since we all seem to have OCD about fasteners here's a history lesson published by Nord-Lock

Richard Newton

[kodioneill]

High Richard : Nice blog I enjoyed reading it. I used to work as a technician at a BMW dealership in the early 1980's we used a method that would tighten the bolt or nut to a specified torque then use a torque angle gauge to further stretch the (spring). Now I understand why. I was curious that you didn't mention it in your blog.

Michael

[ClickClickBoom]

Hey,
Follow up! I installed the new 12.9 8x55 bolts with the Nord-Lock washers:



Shot showing the infamous deformation:




Orange stuff is officially called Torque Stripe, we call 'em tork boogers!

I will retorque the bolts tomorrow allowing the full deformation to take place. And the waiting game will start.

[Geneman]

So is the most curent recommendation from the brain trust at pelican that we use the nord-locks for the cv bolts on an 88 carrera. Use them only once of course, torque them to what tension dry (no oil)? Then still re-torque after 100 or so miles? Is this a better solution and fastener+locking system than the stage8 locking washer system sold by ideola? ( i have been using these)

thanks very much frank

rauscher@wistar.org

[RichardNew]

Torque angle is fairly common on new cars. Most of the Vintage Motorsport readers are working on older race cars. You just can't cover it all. This discussion right here is testimony to that. People have written books on this stuff.

Richard Newton

[ClickClickBoom]

Frank,
Watch the video on the Nord-Lock link I posted, just about everything else has a rather spectacular failure rate using the Junkers test protocol. The '88 with the 10mm bolts allows more clamping force, but I think that the locking issue is still in place. After watching the video, reading up on the dynamics of bolted joints, I became a believer in the Nord-Lock system. The Schnorr washer is also very good, regular split washers, not so much, in a highly stressed critical application like CV axles. I think that the suggestion from Nord-Lock to use lubrication, and reducing the torque allows the washer to do its job. I have in the shop over a hundies worth of advanced locking system washers.

[Geneman]

thanks click got it ..i am convinced... where do i purchase theses washer systems for the cv axle bolt application? thanks frank

[ClickClickBoom]

Originally Posted by Geneman

thanks click got it ..i am convinced... where do i purchase theses washer systems for the cv axle bolt application? thanks frank

Here is where I got mine:
50 25 Pair 3 8" 10mm Nord Lock Vibration Proof Lock Washers | eBay

Go to the Nord-Lock website and read the PDF and watch the video. Check your bolt length, I am not up to speed on the 10mm bolting system, you might have to source slightly longer bolts to keep your thread engagement correct. Good to go!

[ClickClickBoom]

Hello,
Retorqued the new bolts and Nord-Locks, on every bolt there was 0 degrees of rotation on the torque check. I will recheck the bolts after a couple hundred miles.
eric