STD 01-01-001 - Defining the Term "Nominal Diameter"

This instruction provides clarification for the use of the term "nominal diameter" in Section 1910.23(e)(3)(ii), and to direct answers to inquiries. Old STD 1-1.1 - Defining the Term "Nominal Diameter". The term "Nominal Diameter" when used to describe the size (diameter) of pipe used in construction of standard railings and posts means the outside diameter. The requirements that pipe railings and posts shall be at least one and one-half inches nominal diameter means that the outside diameter of such shall be not less than one and one-half inches.

Note: When Subpart D - Walking and Working Surfaces was updated in 2016, 1910.23 was updated and now covers ladders. However, OSHA did not archive this STD so it is still active. 

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