This specification covers the basic and design forms, lead, classification, and nominal size of the screw thread used for mounting the objective assembly to the body or lens turret of microscopes. It is based on, and intended to be interchangeable with, the screw thread introduced and adopted many years ago by the Royal Microscopical Society of Great Britain, generally known as the "RMS thread" and now almost universally accepted as the basic standard for microscope objective mountings.

This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

1. Scope

1.1 This standard covers the screw thread used for mounting the objective assembly to the body or lens turret of microscopes. It is based on, and intended to be interchangeable with, the screw thread introduced and adopted many years ago by the Royal Microscopical Society of Great Britain, generally known as the “RMS thread” and now almost universally accepted as the basic standard for microscope objective mountings. Formal recognition, however, has been extremely limited.

1.2 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASA Standard

ANSI Standard

Index Terms

microscope; thread; Laboratory apparatus--specifications; Microscopic examination; Objective screw thread; RMS (Royal Microscopical Society) thread; Screw thread;

ICS Code

ICS Number Code 37.020 (Optical equipment)

Citing ASTM Standards

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