A-A-55600B
3.3 Precision tolerance. The bearing precision tolerance level shall be RBEC-1 as defined in
ABMA 20, "Radial Bearings of Ball, Cylindrical Roller and Spherical Roller Types, Metric
Design". The associated radial internal clearance shall be one of the coded options listed in
table III (see 7.3(d)).
TABLE III. Precision tolerance requirements.
Code
Tolerance class
Radial internal clearance
C2
Group 2 (less than normal)
C0
Group N (normal)
RBEC-1
C3
Group 3 (greater than normal)
C4
Group 4 (greater than 3)
3.4 Material.
3.4.1 Rings and rollers. Rings and rollers shall be made of chromium-alloy steel 52100
(UNS G52986) conforming to SAE-AMS 6440, "Steel, Bars, Forgings, and Tubing 1.45Cr
(0.93 - 1.05C) (SAE 52100) For Bearing Applications". The hardness of rings and rollers shall
be 58 to 66 RC in accordance with ASTM E 18, "Standard Test Methods for Rockwell Hardness
and Rockwell Superficial Hardness of Metallic Materials".
3.5 Load ratings. Basic load ratings shall be calculated using the method specified in ABMA 11,
"Load Ratings and Fatigue Life for Roller Bearings".
4. REGULATORY REQUIREMENTS
4.1 Recovered materials. The offeror/contractor is encouraged to use recovered materials to the
maximum extent practicable, in accordance with paragraph 23.403 of the Federal Acquisition
Regulation (FAR).
5. PRODUCT CONFORMANCE PROVISIONS
5.1 Product conformance. The products provided shall meet the salient characteristics of this
CID, conform to the producer's own drawings, specifications, standards, and quality assurance
practices, and be the same product offered for sale in the commercial marketplace. The
government reserves the right to require proof of such conformance.
5.2 Market acceptability. The product offered must have been previously sold either to the
government or on the commercial market.
6. PACKAGING
6.1 Preservation, packing, and marking. Preservation, packing, and marking shall be as
specified in the acquisition order (see 7.3(e)).
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