ANSI ABMA ISO 3290:1998 pdf free download – Rolling bearings – Balls – Dimensions and tolerances
1 Scope
This Intemational Standard specifies requirements tor finished steel balls for rlling bearings.
2 Normative references
The tllowing standards contain provisions, which through reference in this text, constitute provisions of this Internationai Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and partes to agreements based on this Interational Standard are encouraged to investigate the possiblity of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.
ISO 4288:1996. Geometrical Product Specifications (GPS) – Surface texture: Profile method – Rules and procedures for the assessment of surface texture.
ISO 4291:1985,. Methods for the assessment of departure from roundness – – Measurement of variations In radius.
3 Definitions
For the purposes of this Intemational Standard the tllwing definitions apply.
3.1 nominal ball diameter, Dw: diameter value which Is used ftor the general identification of a ball size.
3.2 single ball diameter, Dws: distance between two parallel planes tangential to the actual surface of a ball.
3.3 mean ball diameter, Dwm: arithmetical mean of the largest and the smallest of the single diameters ofa ball.
3.4 variation of ball diameter, Vows: diference between the largest and the smallest of the single diameters of a ball.
3.5 surface irregularities and form parameters: Various types of deviation from the perfect spherical ball surface, uniformly distributed and repeated around the ball surtace.
2 Surtace deftects (and their limits) are not specfied in this Intematonal Standard but may be defined as follows:
surtace defect: Element, iregulanty or group of elements and irregulanties of the real surtace, unintentionally or accidentally caused dunng manufacture, storage, handling or use of the surface. Such types of elements or iregulantes difter considerably from those consttuting the surface roughness and should not be considered dunng the measurement of the surface roughness, (see 4.2, note 2).
3.5.1 deviation from spherical form: Greatest radial distance. in any equatorial plane, between the smalest circumscnbed sphere and the greatest inscnbed sphere with their centre common to the least square sphere centre.
NOTE一Intormaton about the measurement of this deviation is given in annex B.
3.5.2 waviness: Surface rregularities of random or periodical deviation from the ideal spherical form.
NOTE- It is recommended that waviness be evaluated as velocity amplitude. In practce, the waviness components are separated from the real surtace by a waviness analyser (riters).
3.5.3 surface roughness: Surface irregularities with relatively small spacings, which usually include irregularities resulting from the method of manufacture being used and/or other influences.
NOTE – These iregulanties are considered wthin the limits which are conventionally defined, ftor example, wthin the limits of the sampling length.
3.6 ball lot: definite quantity of balls manufactured under conditions presumed unifom and which is considered as an entity.
3.7 mean diameter of ball lot, Dwml: anthmetical mean of the mean diameters of the largest ball and the smallest bal in a ball lot.
3.8 variation of ball lot diameter, Vom: difterence between the mean diameters of the largest ball and the smallest ball in a ball lot.
3.9 ball grade, G: specific combination of dimensional, fom, surface roughness and sorting tolerances tor balls.
NOTE- Ball grade in identfhed by the ltter G and a number.