Guarding lathe chucks under the general machine rule

January 26, 1979

MEMORANDUM FOR: GABRIEL GILLOTTI
Regional Administrator

ATTENTION: LAWRENCE E. GROMACHEY

THRU: DONALD E. MACKENZIE Field Coordinator

FROM: IRVING WEISBLATT Acting Director Federal Compliance
and State Programs

SUBJECT: Letter Dated June 9, 1978, to Donald Shay Concerning
the Guarding of Lathe Chucks and the Appropriate Standard

There is no specific OSHA standard for lathe chucks. It has been, and continues to be OSHA's policy that in the absence of an applicable specific standard for a machine, the general requirements for all machines, 29 CFR 1910.212(a)(1) shall apply. When there is a National Consensus Standard, it can be used as a guideline for applying the general requirements of 29 CFR 1910.212(a)(1).

There is a National Consensus Standard, ANSI B11.6-1975, Safety Requirements for the Construction, Care, and Use of Lathes. Section 5 of this standard contains the safeguarding requirements. Paragraph 5.3 states:

Work-Holding-Device Hazard. When the work holding or driving device in the clamped mode has components that extend beyond the outside diameter of the holding device; or the periphery of the body of the holding device is of irregular shape; or a pinch point is created and the operator is not effectively protected by location, machine components, or other means from coming into contact with these projections; a fixed or moveable guard, device, awareness barrier, or peripheral cover over area exposed to the operator shall be required.

Therefore, automatic or semiautomatic lathes used for production operations that have work-holding device such as a lathe chuck, operating under the conditions outlined in paragraph 5.3 of the ANSI B11.6-1975, requires a fixed or movable guard. All guarding methods stated in paragraph 5.3 are acceptable except the awareness barrier as this latter barrier does not meet the requirements of 29 CFR 1910.212(a)(1). All work-holding devices do not require guarding. Therefore, a thorough evaluation must be conducted of the work-holding device.