Rebar bending is one of those tasks that looks trivial until you try to do it consistently by hand — and then you realize that every stirrup, hook, and L-bend in a reinforced concrete project depends on producing the same angle, the same radius, and the same leg length over and over again. This video walks through the construction of a manual bending jig that turns that finicky process into a repeatable one, using nothing more than a steel plate, a couple of strategically placed pegs, and a lever arm.

What makes the build worth watching is the geometry. The placement of the fulcrum peg versus the forming peg determines the inside bend radius — too tight and you'll crack the rebar, too loose and your stirrups won't fit the form. The video shows how to size those pegs against the rebar diameter (the rule of thumb is roughly 4× the bar diameter for the inside radius on grade 60 rebar) and how a fixed stop lets you reproduce the same angle without measuring each time.

It's a practical introduction to jig design in general: locate, constrain, repeat. The same principles apply whether you're bending steel, drilling dowel holes, or routing identical parts. For anyone pouring footings, building a small shop, or just curious about how reinforced concrete actually gets made, this is a solid hour of fundamentals.