Calculators / Corner obstruction

90° around a corner obstruction

When a pipe, box or column sits in the corner where your run turns, cut across it with two 45° bends instead of one 90. Pick the shape and enter its size to get the spacing between your bends.

Outside diameter of the pipe in the corner, in inches

Results

Center to center of bends
–
Multiplier–
  1. Make your first mark where the first bend should be centered.
  2. Make the second mark – from the first.
  3. Bend 45° at each mark, in the same direction and without rolling the conduit, to make the 90.

iBend Pipe can also lay out this bend with your bender's exact radius and mark positions. Get the app.

Where the multipliers come from

The conduit runs along one surface, turns the corner and runs along the other. Instead of a sharp 90 into the corner, two 45° bends cut a diagonal across it. The multiplier is the length of that diagonal for each shape, measured from bend to bend.

  • Round, × 2.4: the diagonal just touches the pipe. Its length works out to D × (√2 + 1) = 2.414 × D, rounded to 2.4.
  • Rectangle, × 1.4: the diagonal passes the box's inside corner. Its length is (X + Y) × √2 = 1.414 × (X + Y), rounded to 1.4. Only X + Y matters, so a 10″ × 30″ box and a 20″ × 20″ box get the same spacing.
  • Square turned 45°, × 3: the square's flat face sits against the diagonal. Its length works out to exactly 3 × the side.

These are quick field numbers. They don't account for your bender's radius or the conduit's thickness, so leave a little room. See where corner multipliers come from for the full math.