Abstract: A retainer arrangement is disclosed for securing punches, dies or similar machine tool elements within a bore in a tool holder body, the retainer providing for secure and accurately repeatable orientation of the punch or other element within the bore. The retainer comprises a conically tapered pin retainer having a threaded shank portion adapted to be received into a threaded portion of a retainer seat extending into the holder body transversely to the holder bore and having a conically tapered portion partially intersecting the same. The leading end of the tapered pin retainer is tapered to mate with the tapering portion of the retainer seat and with a complementary conical tapered groove formed in the punch shank, to securely retain the punch or other machine element within the holder body, and also to precisely and repeatably orient the same with respect to the holder body bore in receiving the same.