GB/T 131-2006Geometrical Product Specifications (GPS) -- Indication of Surface texture in technical Product documentation (English PDF)

Foreword

This Standard equivalently adopted ISO 1302.2002 Geometrical Product Specifications (GPS)

– Introduction of Surface Texture in Technical Product Documentation (English Version).

For the benefit of use, this Standard made the following editorial modifications.

--- Delete the Foreword and Introduction in the International Standard;

--- Modify some descriptions apply to the international standard into that apply to Chinese

Standard; e.g.. modify the marking example in the international standard such as Ralpha

1 Scope

This Standard specifies the rules for the indication of surface texture in technical product

documentation (e.g., drawings, specifications, contracts, reports) by means of graphical

symbols and textual indications.

2 Normative References

The provisions in following documents become the provisions of this Standard through

reference in this Standard. For dated references, the subsequent amendments (excluding

corrigendum) or revisions do not apply to this Standard, however, parties who reach an

agreement based on this Standard are encouraged to study if the latest versions of these

documents are applicable. For undated references, the latest edition of the referenced

document applies.

3 Terms and Definitions

For the purposes of this Standard, the terms and definitions given in GB/T 6062, GB/T 3505,

GB/T 10610, GB/T 13361, GB/T 18777, GB/T 18618, GB/T 18778.2, GB/T 18778.3, GB/T

4 Graphical Symbols for the Indication of Surface Texture

When complementary requirements for surface texture characteristics have to be indicated, a

line shall be added to the longer arm of any of the graphical symbols illustrated in Figures 1

to 3, as shown in Figure 4.

5 Composition of Complete Graphical Symbol for Surface Texture

The mandatory positions of the various surface texture requirements in the complete graphical

symbol are shown in Figure 6.

6 Indication of Surface Texture Parameters

See annex E. If the parameter designations are indicated as in annex E, without "max". this

means that the default definition or the default interpretation of the specification limit ("16 %-

rule". see 5.2 of GB/T 10610-1998) is invoked. See 5.3 of GB/T 10610-1998 for an indication

of the "max-rule" for the interpretation of the specification limit.

7 Indication of Manufacturing Method or Related Information

The surface texture parameter value of an actual surface is strongly influenced by the detailed

form of the profile curve.

8 Indication of the Surface Lay

The surface lay and direction of the lay emanating from the manufacturing process (e.g.,

traces left by tools) may be indicated in the complete symbol by using the symbols shown in

Table 2 and illustrated by the example in Figure 14.The indication of surface lay by the

defined symbols (e.g., the perpendicular symbol in Figure 14) is not applicable to textual

indications.

9 Indication of Machining Allowance

In the same drawing, the surface of multiple machining operations can be marked with

machining allowance, for example, the machining allowance is given in a casting and forging

drawing representing a switch of a finished part (see Figure 15). The machining allowances

given in Figure 15 are not applicable to text.

11 Position on Drawings and other Technical Product Documentation

If there is no risk of misinterpretation, the surface texture requirement may be indicated in

connection with the dimensions given, as shown in Figure 19.

Annex A

(Normative)

Proportions and Dimensions of Graphical Symbols

In order to harmonize the size of the symbols specified in this International Standard with

those of other inscriptions on technical drawings (dimensions, geometrical tolerances, etc.)

the rules given in ISO 81714-1.1999 are applicable.

Annex B

(Informative)

Meanings of Surface Texture Symbols and Codes

Annex C

(Informative)

Examples of Indication of Surface Texture Requirements

The examples of indication of surface texture requirements are shown in Table C.1.

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