HomeArticlesSnapping a Steel Rod 1000x slower – The Slow Mo Guys
Snapping a Steel Rod 1000x slower – The Slow Mo Guys
October 12, 2019
Gav: Hello there, the Internet, I’m Gavin. Dan: I’m Dan. Gav: We’re the Slow Mo Guys, and we’re filming something I’ve never seen in slow-motion before. Dan: I’m not sure how many people have, in slow-motion. What we’ve got here is a number 11, grade 60 rebar(reinforcing bar) so it’s pure steel beam, basically. Ugh, it’s one and a half inches thick, so it’s absolute beast. Gav: And uh, we’re gonna pull it apart.
Dan: *laughs* Yeah, we’re gonna rip it apart. Gav: Using this here machine-
Dan: I’ve been working on my back recently. Gav: Yeah, first let’s see if you can pull it apart.
Dan: *exerting strength* Oh, god Gav: You want a tug’o’war? Let’s try it. *grunts* Gav: I’m not gonna manage, I’m not gonna manage. Dan: So this, apparently, has a rate to how much it can be pulled apart. And this one can pull apart up to 220 (kips), which is 220,000 pounds of pulling-apart force. And we wanna find out what this’ll break at.
Gav: What’s that in horsepower? *calculating*
Gav: A fleet? Let’s split.
(nice pun) Dan: *cringes* Oh, for goodness’ sake. Gav: Ready?
Dan: Ready. Gav: It has begun. Dan: World’s meatiest machine is doing its work. Gav: The hard part will be… is guessing the framing, so I’m filming quite wide. Dan: We got 60 kips.
Gav: 60,000 pounds. Dan: It’s starting to make noise now.
Gav: Yeah, the occasional creak. Dan: Yeah, is it gonna be loud? Gav: I wonder if it’ll-
Dan: *shocked* Gav: We’ll see some visible stretching. What’s it at now?
Dan: 79-80 80 kips. Oh, there’s bits falling off there.
Gav: Yep. Dan: Oh god… Gav: We got more kips than frames. Dan: I’m really nervous.
Gav: *laughs* What are we at?
Gav: 100,000 It’s chippin’ like heck. It’s like the inside is stretching more than the outside can take Dan: I’m scared. 125. Oh god. Gav: I don’t even think we got the framerate for this.
Dan: *shocked* Oh, wow shite it. Gav: *laughs* Why you freaking out, man? What are we at? Dan: 140. Both: 140!? Gav: Thousand. That’s like 10 mega-stone. Dan: mega-stone? *laughs* Just go! Gav: Any day now. Go on, son. Look at that stretch! Look at it stretchin’! Both: *yells* Dan: Good lord! My heart jumped!
Gav: *laughs* Lovely clean break. Dan: 157.4 thousand pounds Gav: Alright, let’s see what that look like. *excited*
Gav: It gets dark like… a clouded mist *excited*
Dan: That’s amazing! *slow-mo music* *slow-mo clang* Dan: That’s the best way to clean a steel bar, is to break it in half. No gubbins is left after that. Gav: Then all the stuff from above came down later. God, that went.
Dan: Absolutely did, look at this. *stuttering* This is actually amazing. This is- This is the bit that actually broke. It’s really warm to the touch. So like you start here, it’s cold, but then it gets warmer and warmer and then it’s just like hot Cos it’s stretched out-
Gav: Oh my god
( ͡° ͜ʖ ͡° ) That’s just from the friction, that’s just from the stretching that caused all that heat. Dan: That is really cool.
Gav: Bloody hell. Dan: So to set the machine up, before it can start pulling, it has to like, grip it on either end and you can see here where the grips are just cut into the steel and just absolutely, completely crushes it so that you can pull it apart. You can see the little individual notches. Gav: That was… hefty. Dan: That was scary. I jumped. Gav: It’s amazing how it just cleans and takes an entire layer of itself off. Dan: Well, it was meant to, because it was probably about here and then it just suddenly went like *stretching sounds* bang Gav: and you can see it’s sort of like necked in where it broke cos that’s where it was stretched. And even in slow-mo, it was instant. Absolutely instant. We’d probably need like, a million frames to get the propagation of that crack. Dan: The machine just made me feel completely inadequate. Gav: Well yeah, I mean I can pull, what, 10 pounds?
Both: *laughs* Gav: Hopefully you enjoyed that video. Feel free to follow us on Twitter. Subscribe, we got loads of slow-mo, we’ve got a second channel, we’ve got merch! And let us know if you like these… science-related videos. Dan: I do.
Gav: I bloody do. Bloody love science.
Dan: Bloody love it?
Gav: Love it.