How Many Threads Does Nut Need To Be Strong?

How Many Threads Does Nut Need To Be Strong? Or how about bolt? How strong is one thread? how about two? We are going find out using our 150 ton hydraulic press and 240 ton force sensor / load cells!
Do not try this at home!! or at any where else!!

Music Thor's Hammer-Ethan Meixell

[UrbusGurbus]

I'd love to watch this with a thermal camera and see how much the temperature changes as the metal is forced

[lephtovermeet]

Years later and this channel is still great. You guys bring so much happiness into my life.

[konackt]

Thread stripping is always expected on the bolt before the nut. As suggested it is because the shear plane is at a larger diameter. This means there is more area for the shear force to act over.

The formula for thread stripping is roughly:

Thread profile width (half pitch)
* Diameter at shear plane of thread (this is bigger for nut than for bolt)
* Pi
* Number of threads of engagement.

[lukes]

You could take full size nuts and bore them out to the desired number of threads. That should remove the material thickness of the nut as a variable and prevent the cupping.

[basssie]

Mechanical Engineer here, general rule for designing: half the thread diameter for a nut. If you do the proper calculations, it mostly depends on the material of the nut. Funny enough, the nut is usually stronger than the bolt in order to see threads shearing off before part faillure occurs.

[Fix_It_Again_Tony]

A graph of the amount of force over the number of threads would have been a good way to visualize the results. Once trace for the cut down nuts and one for the bolts.

Otherwise, stellar video. These are really interesting.

[carolbritton]

You are exactly right. The bolt threads always fail before nut because of the smaller root diameter (or diameter near the solid metal)

[Liberty]

Mechanical Engineer here. If you are really interested look up the Handbook of Bolted Joints by Bickford. When designing joints you have to do much more than look at the shearing of the threads. The industry usually dictates how joints are designed. Steel Construction, Piping, Aerospace, etc all have different standards.

[PhilG]

Another Mechanical Engineer here! From the Strength of Materials class in the first year we were taught that the first three threads (in tension) take 98+% of the load. Since you are testing in compression the results are different. BTW ASMET and BSMET, retired after 40+ years in Forensic Failure Analysis ...

[KillianTwew]

To be fair, I think 9:36 the peak from the threads was 19K, while 26K was the peak from the press slamming into your test equipment due to the sudden release of the threads.

[RiddleTime]

Seeing your hand next to the bolts made me realise that the bolts are pretty huge. Nice video!

[markdavies]

The cupping of the thin nuts absorbs some of the force. With the modified bolts, the threads take all the force.

[DagothXil]

I love HPC videos that make me think "I wonder if this'll ever be sourced in a materials science paper"

[misterbryton]

You should crush powdered candy with rock maker to make a jawbreaker

[wintrparkgrl]

after all these years you manage to keep a simple idea interesting and engaging

[EDoyl]

The cupping deformation is interesting, since when it deforms like I think that the interior diameter should get wider at the bottom and the nut might "let go" of the lower thread. The bolts you made with only a few threads should be testing exactly that, since it's the same number of threads but without the nut easily deforming, but the results of that test were definitely strange. I'm sure at some point a manufacturer somewhere did all sorts of tests like this to characterize the standardized threads.

[MikkoRantalainen]

Here's my guess before watching the video: 7 (based on existing tests I've heard about).
It seems that 4 threads was surprisingly strong already. However, it seems you measured *compression* when real world bolt usage will see stretching forces only. Logically compression forces make the bolt thicker so it should make the connection stronger.

Of course, building a test setup that can those huge stretch bolts is much harder.

[raffal]

Hi, Great video as always. You should (as you mentioned) test with a "pull" configuration. by testing pull strength, you would be able to check at which point adding threads is pointless because threads are strong enough to break the bolt itself.Here, you really tested the material strength and the differences you saw, were probably caused by different alloys from which bolts and nuts are made. Cant wait for pull test wideo.

[ResilienceOnPurpose]

This is a topic I've actually wondered about in the past deciding if my jeep wheel studs were long enough for my wheel nuts to get maximum engagement. What I found in research was that the nut should have as much thread engagement as the bolt shaft is wide, minimum.
In both your nuts and bolts here, the surface was machined into, decreasing the case hardening of the nut or bolt. The only way I can think of the avoid that is to only screw an uncut nut onto an unmachined bolt as many threads as you want to test.
Good video, thanks.

[GLASSGHOSTHUNTERS]

4:46 could be an entire video. Look how sweet Anni is to moisturize Lauri's face. Next level ASMR!