In such fast-paced times, there are two YouTubers who are always looking to slow things down. The Slow Mo Guys, Gavin and Dan, got the opportunity to use some heavy duty machinery and decided to see what pulling apart a steel rod would look like 1000x slower.
While visiting Purdue University in West Lafayette, Indiana, Gavin and Dan got their hands on a machine that can pull apart up to 220 kips, which is 220,000 pounds of “pulling apart” force. For their latest experiment, they chose to stretch a #11 grade 60 reinforcing bar until it snapped.
The Slow Mo Guys placed the 1.5 inch thick steel beam in the machine and waited in suspense as more and more force was applied to stretch the reinforcing bar apart. At just after 157 kip, the bar finally separated with a loud snap that sent both Gavin and Dan jumping backwards.
Reviewing the footage at 28,500 and then 148,000 frames per second, the forced divide shows the explosive clean cut the moment it happens in ultra slow motion. Showing the original length of the reinforcing bar, the machine managed to actually stretch it a good amount before the breaking point.
Even in the ultra slow motion, the moment the reinforcing bar breaks still appears instant. After analyzing the snapped reinforcing bar, Dan found that it felt significantly warmer in temperature the closer he touched to the breaking point just due to the friction.
“To set the machine up, before you can start pulling, it has to like grip in on either end,” Dan says before showing the cuts in the steel made due to the force necessary to pull the rebar apart.
“It’s amazing how it just cleans, it just takes an entire layer of itself off,” Gavin says while observing the damage done to the stretched reinforcing bar.