ASME Y14.5-2009 pdf download.Dimensioning and Tolerancing Engineering Drawing and Related Documentation Practices.
1.3 DEFINITIONS The following terms are defined as their use applies in this Standard. Additionally, definitions throughout the Standard of italicized terms are given in sections describing their application. Their location may be iden- tified by referring to the index. 1.3.1 Angularity angularity: see para. 6.3.1. 1.3.2 Boundary, Inner boundary, inner: a worst-case boundary generated by the smallest feature (MMC for an internal feature and LMC for an external feature) minus the stated geomet- ric tolerance and any additional geometric tolerance (if applicable) resulting from the feature’s departure from its specified material condition. See Figs. 2-12 through 2-17. 1.3.3 Boundary, Least Material (LMB) boundary, least material (LMB): the limit defined by a tolerance or combination of tolerances that exists on or inside the material of a feature(s). 1.3.4 Boundary, Maximum Material (MMB) boundary, maximum material (MMB): the limit defined by a tolerance or combination of tolerances that exists on or outside the material of a feature(s). 1.3.5 Boundary, Outer boundary, outer: a worst-case boundary generated by the largest feature (LMC for an internal feature and MMC for an external feature) plus the stated geometric tolerance and any additional geometric tolerance (if applicable) resulting from the feature’s departure from its specified material condition. See Figs. 2-12 through 2-17. 1.3.6 Circularity (Roundness) circularity (roundness): see para. 5.4.3.
1.3.17.2 Datum Feature Simulator (Physical). datum feature simulator (physical): the physical boundary used to establish a simulated datum from a specified datum feature. NOTE: For example, a gage, fixture element, or digital data (such as machine tables, surface plates, a mandrel, or mathematical simulation) —although not true planes — are of sufficient quality that the planes derived from them are used to establish simulated datums. Physical datum feature simulators are used as the physi- cal embodiment of the theoretical datum feature simulators during manufacturing and inspection. See ASME Y14.43. 1.3.18 Datum Reference Frame datum reference frame: see para. 4.1. 1.3.19 Datum, Simulated datum, simulated: a point, axis, line, or plane (or combi- nation thereof) coincident with or derived from process- ing or inspection equipment, such as the following simulators: a surface plate, a gage surface, a mandrel, or mathematical simulation. See para. 4.6. 1.3.20 Datum Target datum target: see para. 4.24. 1.3.21 Diameter, Average diameter, average: see para. 5.5.3. 1.3.22 Dimension dimension: a numerical value(s) or mathematical expression in appropriate units of measure used to define the form, size, orientation or location, of a part or feature. 1.3.23 Dimension, Basic dimension, basic: a theoretically exact dimension. NOTE: A basic dimension is indicated by one of the methods shown in Figs. 3-10 and 7-1. 1.3.24 Dimension, Reference dimension, reference: a dimension, usually without a tolerance, that is used for informational purposes only.
1.3.25.2 Related Actual Mating Envelope. related actual mating envelope: a similar perfect feature coun- terpart expanded within an internal feature(s) or con- tracted about an external feature(s) while constrained either in orientation or location or both to the applicable datum(s). See Fig. 1-1. 1.3.26 Envelope, Actual Minimum Material envelope, actual minimum material: this envelope is within the material. A similar perfect feature(s) coun- terpart of largest size that can be expanded within an external feature(s) or smallest size that can be con- tracted about an internal feature(s) so that it coincides with the surface(s) at the lowest points. Two types of actual minimum material envelopes — unrelated and related — are described in paras. 1.3.26.1 and 1.3.26.2. 1.3.26.1 Unrelated Actual Minimum Material Env- elope. unrelated actual minimum material envelope: a similar perfect feature(s) counterpart contracted about an internal feature(s) or expanded within an external feature(s), and not constrained to any datum reference frame. See Fig. 1-2.
www.findfreestandards.com