This specification covers the dimensions and tolerances for both driving and driven elements in square drive interconnections on stainless steel surgical instruments used for drilling, tapping, driving, or placing of medical devices during surgery. The specification is intended to lessen the chance of accidental disengagement of surgical instruments.

1.1 This specification applies to interconnections of surgical instruments used for drilling, tapping, driving, or placing of medical devices during surgery.

1.2 This specification includes dimensions and tolerances for both driving and driven elements.

1.3 The specifications given in ASME B107.4M-1995 are designed for industrial applications and are considered too loose for surgical applications. Springs used for industrial applications are generally made from carbon steel and are capable of higher loads than their stainless steel counterparts. The specifications given in this standard have been written to lessen the chance of accidental disengagement of surgical instruments. This accidental disengagement could injure the patient or end user, or damage or contaminate the instrument.

1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.