Abstract: A clamp for clamping extendible supports in flexible tooling system includes three overlapping tapered collets surrounding the extendible support, with a set of ball bearings positioned between each of the collets. The middle collet is tapered in a direction opposite to that of the inner and outer collets, so that when the middle collet is pressed by springs into a gap between the inner and outer collet, the inner collet is forced against the extendible support, thereby clamping it. The ball bearings and the three collet assembly prevent the clamp from binding with thermal expansion so that the clamp releases when the force pressing the middle collet into the space between the inner and outer collet is removed. The springs maintain a sustained clamping force so the clamp does not release upon thermal expansion of it components.