(1) Marking direction of the bearing
There are three marking methods for rolling bearings, namely:
a. mechanical method b. electric erosion method c. chemical method
The chemical method is only applicable to a small number of trial products; supplementary clearance group code and precision grade code;
(2) Content and position of the logo
Generally, the bearing code, manufacturing year code and manufacturer code (or trademark) should be marked on the end face of the ferrule. The three are evenly distributed at 120° intervals, and the distribution can also be called evenly for aesthetics. However, it can also be marked on the end face of the shield, cage, retaining ring, seal or dust-proof device according to the requirements of the product drawing. The manufacturing year code shall comply with the regulations of the product design department of the manufacturer.
If the effective width of the end face of the ferrule is less than 0.8mm, its mark is allowed to be marked on the outer diameter and on the packaging; for the mark greater than 0.8mm, it can be marked according to the following rules:
1) For non-separable bearings, it is allowed to mark the complete mark on the end face of a ring. In order to distinguish the reference plane of another ferrule, it is allowed to mark the process mark on the non-reference plane of the ferrule.
2) For separable bearings, a complete mark must be marked on the end face of each ring. However, it is also allowed to mark the bearing code and manufacturer code (or trademark) on the end face of one of the rings at intervals of 180°.
3) When several types of bearings use the same ferrule, the codes of these bearings can be marked on the end face of the ferrule, or the mark can be added by chemical method.
[Example] When bearings 627 and 618 use the same outer ring, "627-618" can be marked on the end face of the outer ring.
[Example] When bearings NU2C4, NJ204 and RNU204 use the same outer ring, "NU-NJ-RNU204" can be marked on the end face of the outer ring, and the common part "204" can be marked by mechanical method.
(3) Logo font and character height
The font shall comply with the regulations of the product design department of the manufacturer. The character height is selected according to the following heights: 0.5, 0.7, 1, 1.2, 1.5, 2, 2.5, 3, 4, 5mm. If necessary, in accordance with the provisions of the product drawings, the parts of the same bearing can use fonts of different sizes, and the height should be selected as two specifications adjacent to each other as much as possible.
(4) Mark requirements
1) The logo must be complete and complete.
2) The handwriting must be correct and clear; the lines should be uniform in thickness. The writing should have a certain depth. For electro-etching method; the character height is less than or equal to 1mm, and the character depth shall not be less than 0.003mm; the character height is greater than 1mm but less than or equal to 2.5mm, and the character depth shall not be less than 0.005mm; 0.01mm.
3) The diameter of the central circle of the logo, the equal division and the font, etc. must not have any visible deviation.
4) The logo font, symbol shape, character width, line width and distance between characters shall comply with the regulations of the product design department of the manufacturer.
5) There shall be no other marks on the surface of the bearing parts except those allowed by the drawings and relevant documents.
6) When the subscriber has special requirements, he can negotiate with the manufacturer, and adopt the required marking method and marking content according to the supplementary technical requirements negotiated.
