frame rail

plural frame rails · alternative framerail

1. automotiveEach of the two main longitudinal structural members of a body‑on‑frame vehicle, running parallel front to rear and supporting the chassis, to which cross‑members, suspension, drivetrain, and body are attached.

   It has been proposed that the length of the middle, parallel portion of the sub-frame comes flush with the inner side of the lower flange of the main frame rail.

   1912 November 27, P. M. Holdt, “The Gasoline Automobile — Its Design and Construction.”, in The Horseless Age., volume 30, number 22, page 833

   1 more example

   Instead of a relatively flat, ladder-like structure with two longitudinal, parallel frame rails, it consists of a central, strong tubular backbone (usually rectangular in cross-section) that carries the power-train and connects the front and rear suspension attachment structures.

   2025 March 24, Wikipedia contributors, “vehicle frame”, in English Wikipedia, Wikimedia Foundation

2. furnitureA horizontal structural member of a furniture frame, typically joining the legs or vertical posts, providing support and rigidity; commonly found in tables, chairs, cabinets, and beds.

   The frame rails must be firmly mortised into the legs to ensure stability.

   1901, Frederick Thomas Hodgson, The Practical Cabinet Maker and Furniture Designer, page 212