Acronyms for Tube Fabrication

The tube fabrication uses certain acronyms that are commonly understood across the industry. Here are the main ones.

XYZ

"XYZ" is commonly understood as XYZ points that define the centerline of a tube shape. They are the endpoints and the intersection points.

The Italian BLM bender standard is an exception.  For BLM, XYZ refers to the three axes of a bender.  In other situations, Italian engineers refer to the three axes as "XYZ."

Tangent Points

Tangent points refer to the points on the centerline where the straights meet the bends.

LRA

LRA means Length, Rotation, (Bend) Angle. It is also called "bender data."  These values can be used to define the three major axes of a bender.

YBC

The original Eaton Leonard standard used "YBC" to mean the three axes of a bender (like LRA).  However, in Eaton Leonard Vector measuring centers, the subtle difference between LRA and YBC is that LRA is considered the nominal (perfect) data, and YBC is considered to as the adjusted bender data.

When starting a new part, it was possible that LRA and YBC could be equal until adjustments were made to the YBC.  So, LRA data is never adjusted to overcome springback and twist.  YBC data is.

FPB

This is Feed, Plane of Bend, and Bend Angle. It is the same as LRA.

FRB

This is Feed, Rotation, and Bend Angle. It is the same as LRA.

Conrac, Absolute, Center Back

These terms all refer to absolute Conrac-style bender data charts commonly used before Eaton Leonard started using the YBC standard. The standard is absolute because the Lengths and the Rotation angles are both absolute. That is, they depend on all the previous values. See this page for more information about this bender data standard.