1.1This specification covers requirements for metric series, tapered roller bearings with a single row of rollers.

1.2Intended Use-The bearings covered in this specification are intended to be used in general industrial and vehicle applications where the operating temperature does not exceed 120°C (250°F).

1.3This specification contains many of the requirements of DS3225, which was originally developed by the Department of Defense and maintained by the Defense Supply Center in Richmond. The following government activity codes may be found in the Department of Defense, Standardization Directory SD-1.²

Preparing Activity	Custodians	Review Activities
DLA-GS4	Army-AT	Army-AV
	Navy-MC	Navy -MC, SH
	Air Force-99	Air Force-84
		Other-NS

1.4The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.