Abstract: A locking system includes a tamper-resistant lock and key. The tamper-resistant lock can include a cylindrical lock body with an upper portion having an engagement surface defining a pattern of engagement features, a housing, and a hidden component sized and shaped to fit within the housing that includes an internal lock base into which the cylindrical lock body fastens and a padlock pin configured to secure the internal lock base to a hasp or staple. The key operable for use with the tamper-resistant lock can include a cylindrical key body defining an engagement cavity configured to receive the engagement surface of the cylindrical lock body, a set of complementary engagement features, a plurality of retractable engagement members, and a retractable collar at least partially covering the cylindrical key body.

Abstract: An adjustable quick change tool holder having an elongated arbor for insertion into a machining apparatus. A tool support member is supported on the arbor. The tool support member releasably supports a cutting tool axially adjustable with respect to the longitudinal axis of the arbor. Guide means is provided for transversely adjusting the tool support member with respect to the arbor. A releasable securing mechanism is included for securing the tool support member at a desired transverse position. The cutting tool is thereby easily adjustable in two mutually perpendicular directions and can easily be replaced.