Standard:

• AS4059
• Revision: E

Reaffirmed:

• 2011-03-18

Revised:

• 2005-05-02

Revision:

• Historical. Access the latest revision: AS4059F

Issuing:

• A-6c1 Contamination And Filtration Committee

Scope:

This SAE Aerospace Standard (AS) defines cleanliness classes for particulate contamination of hydraulic fluids and includes methods of reporting related data (Appendix A). The contamination classes selected are an extension ofbased on the widely accepted NAS 1638 cleanliness classes. Conversion from NAS 1638 cleanliness class specifications to AS4059 class specifications is defined. Comparison of the NAS 1638 classes to AS4059 classes is defined and the differences explained (Appendix B). This document provides versatility in identifying a maximum class in multiple size ranges, total number of particles larger than a specific size or designating a class for each size. NAS 1638 classes based on weight of particles are not applicable to either of these classes and are not included.

History:

Standard	Published	Revision	Status
AS4059F	2013-09-27	Latest	Revised
AS4059E	2005-05-02	Historical	Reaffirmed
AS4059D	2001-04-01	Historical	Revised
AS4059C	2000-08-01	Historical	Revised
AS4059B	1995-03-01	Historical	Revised
AS4059A	1990-03-30	Historical	Revised
AS4059	1988-06-14	Historical	Issued

AKA:

• SAE AS 4059

Sector:

• Aerospace

Topic:

• Fluid power systems
• Hydraulic systems
• Hydraulic fluids