Abstract: An automatic tubing assembly device of modular design and suitable to utilization with thin-walled, flexible tubing is shown in several embodiments. The device includes a mechanical assembly for pure rectilinear motion to avoid tubing damage and an elongated jaw set (18) which applies a force to the tubing (45) over the fitting (1) involved and which flexes outward over the fitting (1). Use of a springed friction member (54) and sliding cam (21) act to achieve the rectilinear motion. The fitting (1) is supported along its length and the entire device is operable from one lever (7) which has only one degree of freedom and thus lends itself to assembly line automated uses. Additionally, multiple axis fittings can be accommodated through simple reconfiguration of the modular design.