Appendix B: Common Pipe And Tube Bending Terms - Jancy Engineering JB2400 Operator's Manual

Appendix B: common Pipe and Tube Bending Terms

Arc: The curved portion of tube or pipe
bends. See Pipe Bending Diagram.
centerline Radius (cLR): Distance in
inches from the center of curvature to the
centerline axis of the tube or pipe bends.
See Diagram.
cold Tube Bending: The bending of pipe
or shapes by cold working methods.
degree: Angle in degrees to which the
pipe bends are formed (i.e. 45 degrees,
90 degrees, 180 degrees, etc.) See Pipe
Bending Diagram.
Easy Way (EZ): Bending of a rectangular
tube with its short side in the plane of the
bend.
Grade: Manufacturers' specification of
material types of pipe or tubes, (i.e. A53B,
T304W SS).
hard Way (hW): Bending of a
rectangular tube with its long side in the
plane of the bend.
I.d.: Inside diameter of the tube or pipe.
Minimum Tangent: The minimum straight
length at the end of a pipe bends required
by the bending machine to form a bend.
Neutral Axis (N-axis): That portion of
the pipe or tube that is neither in compres-
sion or tension.
O.d.: Outside diameter in inches of the
tube or pipe.
Out of Plane: The deviation in the
horizontal plane of a single pipe bend
between its tangent points, based on the
theoretical center-line of the bend.
Ovality: The distortion or flattening of
pipe or tube from its normal, round shape
caused by the pipe bending process.
Roll Past: Small amount of arc bent
beyond a specified degree, used to over-
come spring back.
Spring Back: The amount a pipe is
"unbent" when bending pressure is
released.
Tangent: The straight portion of material
on either side of arc of pipe bends. See
Pipe Bending Diagram.
Tangent Point: The point at which the
bend starts or ends. See Pipe Bending
Diagram.
Wall: The thickness of bending material,
difference between O.D. and I.D. divided by
2. (O.D. – I.D.)/2 (usually in Inches)
Wrinkles: Waving or corrugation of pipe
bends in the inner radius.
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