Kevin has a pry bar, which is a time saver and back saver. One of the best things a pry bar is for, though, is mechanical advantage.

Mechanical advantage is a work multiplier – if you put X number of pounds of force into something, some kind of mechanical advantage is going to double that, triple that, quadruple that, making whatever effort you put out that much more efficient.

Kevin shows his big workbench. Its top is a 1″ piece of solid steel and the rest of the worktable is made out of steel, too, and it has a bunch of stuff piled up on the bottom shelf. Do you think he can pick that thing up by hand?

He can’t come close.

On the floor, Kevin shows how mechanical advantage uses a fulcrum for the lever (pry bar) to pivot on. He uses a piece of 1/2″ x 1″ solid bar stock and a fulcrum, first trying to lift the workbench with the fulcrum out near the handle. He can barely move the table at all. When he moves the metal fulcrum closer to the table leg, though, he picks up the whole leg – 1/4 of the weight of the whole workbench – without straining.

Kevin calls that linear advantage, but what about rotary advantage? He shows a block and tackle. The more pulleys you have at the bottom and the top, the more mechanical advantage. You need less weight pulling on the rope to pick up more weight at the end of the hook.

The only downside to this system: the more pulleys, the more loops for the ropes, the more rope you need. It’s about 9 feet to his ceiling, but he needs about 25 feet of rope to lower the block and tackle’s hook to the ground.

A stock bender is another type of mechanical advantage. Kevin shows the stock bender’s pivot and roller and a little square. He shows where you put in your metal stock to bend it.

But what happens if you’re trying to bend something that might be a little over the rated specification of the machine? Like railroad spikes ….

A railroad spike is 5/8″ x 5/8″ steel. Kevin put it between the two rollers and the pivot and tried to lean on the handle, but he doesn’t have enough lead in his pocket to bend it. He gets out a length of pipe longer than the handle, slips it over, and bends the spike easily, using mechanical advantage on the handle.

Mechanical advantage helps Kevin work better and smarter, protects his back and arms. Mechanical advantage is all around you. For instance, a 10 speed or 12 speed bicycle with all the different gears uses mechanical advantage.

Kevin thanks Terry for asking the question and thanks viewers for watching. Before you go, stick around for another moment to see just how deep his pockets are ….

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