HYDRAULIC PRESS VS TITANIUM BOLTS

Its not that titanium is going to hold that much more tonnage. It's that it'll hold the same tonnage while being half the weight of steel

It would've helped if at the end of this video you put up a chart or listing ranking the various bolt types in both shear off strength and linear pull strength, from best to worst, along with all of the associated failure values so we could study and compare all of the results all together, side by side in a list form for at least 30 seconds or so.

In a few tests you can see the head of the bolt moving well before any yield, meaning bolt has not been properly torqued. Stresses accumulate differently when you have combined stresses and strains. It is always important to torque to specification. As a design engineer we were instructed to avoid putting bolts in single shear or shear at all. Shear stress in steel is traditionally lower than tensile yield strength. Some preferred practices were not being used in these tests.

For any accident investigators out there, it might be interesting if you showed a magnified image the bolt surface after the sheer and tear failures.

My biggest criticism is that you kept mixing up the comparative values on the screen. For example at the end you tested the Chinese titanium then put up the value for the grade 8.8 bolt but labeled it Titanium for Spaceship. Then again when you tested the 12.9 bolt you put up a different value but labeled it Titanium for Spaceship again.

You need to torque the bolts. In the sheer test friction of the plates plays a huge part in the strength.

"Do not repeat at home". Thanks for the warning, I might have been tempted to try this on the industrial hydraulic press I happen to have lying around 😂

Worked for a foundry that produces areospace/medical titanium parts. Some of the suppliers where chinese, they produce good materials. Only issue with the cheaper bolt is the coloring, it indicated the presence on alphacase on the surface of the parts. Alphacase is very brittle so it cause problems for cyclic loads overtime (small cracks will form and weaken the part). Alphacase is formed when titanium is heated since it reacts with oxigen. Alphacase needs to be etched off the surface using hf acid for a quality part, the coloring indicates that the etching process was not properly done. Hope this info helps/clarifies for someone.

Nice job setting up the rig for your tensile strength test. Two things would’ve been nice to see: 1) during the sheer test, that the initial loading for each bolt was uniform. You could’ve done this with a torque wrench. 2) also very much would’ve like to have seen a close-up shot of the broken surface

For people wondering why cheap Chinese bolts might be stronger than the space bolts - the main attribute of a space bolt would be its weight over its strength. The bolt would rate just as strong as it requires to avoid being disproportionately strong for its needs, thus: heavier than it could have otherwise been. You can bet the bolts were manufactured exactly within strength capability witin specific thresholds, in order to allow for as much enhanced weight reduction property as possible.

I agree with all the posters below who said put up a final chart with all the results side by side.

There are many grades of Titanium. We have no idea what is being tested here.

Bravo!!! Class 12.9 bolts are often used when prolonged use under harsh loads risks stretching the bolt rather than breaking it which is why very specific torque settings are required, A good example is Cylinder Head bolts on an engine that need to expand/contract and still remain tight avoiding cylinder head failure :-))

I work on metal stamping dies, and we use 12.9 bolts as standard. I've used some supertanium bolts and have never had one fail, but one of the key issues to consider is the diameter of the fastener being used. Often, the best solution is stepping up to the next size bigger. When breakage occurs the designed fasteners might not have been enough for the load Really like this type of video, a final chart on a dry erase board comparing results, would've been nice.

I remember QC testing 12.9 fasteners in the tensile test, the machine would hop about 4 inches off the ground when it would break and it was a damn heavy machine. Another test QC would do was tap a 1/4 plate with multiple holes and screw bolts and screws into it and torque them down to a certain over loaded level and leave them for a week, sometimes the head would pop off and shoot across the room.

When watching an hydraulic press working is more interesting than 90% of the YouTube content these day...

Haven't read all the comments but some bolts have threads at the gap between the two plates and some are solid, no threads. Threads will weaken the bolt in shear at the thread compared with the unthreaded shaft of the bolt.

It’s just satisfying seeing seemingly indestructible stuff break.

I like the way you set up that shear test!

I have a question about those shear tests. Did you torque them to spec for specific steel or titanium and have the same torque specs for each? Only asking because the bolts are much stronger when torqued when applying to sheer strength. I believe tension strength is improved as well but I haven’t specifically looked into that in the past.