Jim Markle's Bench-Top Brake

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I copied this vice-mounted brake from some pictures that Jim Markle sent me.  This works so much better then pounding the fittings with a hammer and a block of wood.

Here are Jim's pictures:

When I made mine, I added some alignment bolts to hold the face and back jaws  together while inserting the metal.   I had trouble welding the ¼” steel, so I built mine using some angle iron from an old bed frame I had lying around.   You will need to make several front jaws with different radiuses to correspond to the bend radius that you want to use.  

For 4130, the minimum bend radius is 1 x thickness (1T). I try use about 2T or a radius closest to a front jaw that I have already made.  No need to build to minimum standards.  I have bent up to ¹/₈" 4130 steel and it has worked great (See pictures below).

To use it, draw a sight line (or reference line) on your fittings where you want the bend to be.  I usually use a small triangle along the top of the front jaw to verify the sight line is parallel with the top of the jaw. Tighten the vice and pull down on the handle.

You can calculate the bend allowance and sight line using the formula found in Tony Bengale's books or on the web. Whenever possible, just leave the two ends long and trim after bending.