a method and apparatus are disclosed for testing tensile strength of microfilaments . fibers as small as 0 . 001 inch in diameter and 0 . 04 inches in length have been tested , although the method and apparatus of the invention are capable of testing fibers of smaller diameter and length . the invention utilizes a method wherein one or both ends of a microfilament is gripped using resin which is softened sufficiently to accept an end of the microfilament and then allowed to harden . the invention also employs the use of a translation stage capable of controlled three - dimensional movement suited to facilitating gripping of the microfilament .