The successful design and fabrication of structures and systems at the small scale require robust methods for characterizing the mechanical behavior of materials at the same scale. In this paper we describe the design of two flexure-based micromechanical testers capable of measuring forces with an accuracy of 25 μN over a range of 1–30 N, and specimen extensions with an accuracy of 20 nm over a range of 1–5 mm. These force and displacement resolutions and ranges are required in a wide variety of material characterization applications, such as microtensile testing of micrometer-dimensioned films, foils and wires, bending of millimeter-sized beams, as well as micro-indentation. The novel feature of our machines is that they are based on the use of two compound flexures in an integrated monolithic frame: one flexure functioning as a precision guide for actuation, and the other fexure as a linear spring for force measurement. Two machines, one with a maximum load capacity of 1.5 N and the other of 30 N, have been constructed based on this concept. Details of their design, construction, and typical test results are presented in this paper.