Thread tolerance

ISO (International Organization for Standardization) is a worldwide federation of national standards bodies (ISO Member Committees). The development of International Standards is entrusted to ISO Technical Committees. Each Member Committee interested in a study has the right to be part of the corresponding Technical Committee. International governmental and non-governmental organizations, in liaison with ISO, also participate in the work.

Draft International Standards adopted by the Technical Committees are submitted to the Member Committees for approval, before their acceptance as International Standards by the ISO Council.

The International Standard ISO 3508 was established by ISO/TC 2, Fasteners, and submitted to Member Committees in September 1974.

 

It has been approved by the Member Committees of the following countries:

South Africa

Denmark

Portugal

Germany

Finland

Romania

Australia

Hungary

United Kingdom

Austria

India

Sweden

Belgium

Ireland

Switzerland

Bulgaria

Norway

Turkey

Canada

New Zealand

U.R.S.S.

Chile

Poland

Yugoslavia

The Member Committees of the following countries have disapproved the document for technical reasons:

France

Italy

U.S.A

 

PURPOSE AND SCOPE

This International Standard specifies incomplete threads for fasteners with a thread according to ISO 261, ISO metric threads for general purposes - Overview and ISO 262, ISO metric threads for general purposes - Selection of dimensions for bolting.

It is not applicable to threaded fasteners for which special requirements are included in the product standards

Dimensions in millimeters

NOTES

Thread run-outs x normal for all screw types of finish classes A, B and C.

Short x threads only in cases where short threads are required for technical reasons.

Distance normal for all screw types of finish class A.

Distance normal for all screw types of finish class B and C.