GB/T 39799-2021 in English

《GB/T 39799-2021钛及钛合金棒材和丝材尺寸、外形、重量及允许偏差》由TC243（全国有色金属标准化技术委员会）归口，TC243SC3（全国有色金属标准化技术委员会稀有金属分会）执行，主管部门为中国有色金属工业协会。

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This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization — Part 1: Rules for the structure and drafting of standardizing documents.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.

This document was proposed by China Nonferrous Metals Industry Association.

This document is under the jurisdiction of National Technical Committee on Nonferrous Metals of Standardization Administration of China (SAC/TC 243).

Dimensions, shape, weight and tolerances of titanium and titanium alloy bars and wires

1 Scope

This document specifies the sectional shape, dimensions, tolerances, shape and weight of titanium and titanium alloy bars and wires.

This document is applicable to titanium and titanium alloy wires with the diameter of 0.1 mm ~ 7.0 mm (hereinafter referred to as wires); titanium and titanium alloy round bars with diameters of more than 7.0 mm ~ 450.0 mm (hereinafter referred to as round bars); titanium and titanium alloy square bars with side length of 30.0 mm ~ 450.0 mm (hereinafter referred to as square bars); titanium and titanium alloy flat square bars with thickness of 25.0 mm ~ 204.0 mm and width of 25.0 mm ~ 254.0 mm (hereinafter referred to as flat square bars).

2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

3.1 roundness
degree to which the cross-sectional shape of a round bar approaches a theoretical circle

3.2 squareness
cross-sectional shape of square and rectangular bars approaches the degree of theoretical squareness

4 Sectional shape

4.1 See Figure 1 for sectional shapes of round bars and wires.



Key:

D — the diameter.

Figure 1 Sectional view of round bar and wire

4.2 See Figure 2 for the sectional shape of square bar.



Keys:

a — the side length;

r — the chamfer radius.

Figure 2 Sectional view of square bar

4.3 See Figure 3 for the sectional shape of flat square bar.



Keys:

b — the width;

h — the thickness;

r — the chamfer radius.

Figure 3 Sectional view of flat square bar

5 Dimensions and tolerances

5.1 Section dimensions and tolerances

5.1.1 The diameters and tolerances of wires shall meet those specified in Table 1.

Table 1 Diameter and tolerance of wire
In mm
Diameter Tolerance
Class I Class II
0.1 ~ 0.2 0
-0.025 —
> 0.2 ~ 0.5 0
-0.04 —
> 0.5 ~ 1.0 0
-0.06 —
> 1.0 ~ 2.0 0
-0.08 —
> 2.0 ~ 3.0 0
-0.10 0
-0.03
> 3.0 ~ 4.0 0
-0.10 0
-0.02
> 4.0 ~ 7.0 0
-0.14

5.1.2 The sectional dimensions and tolerances of round bar and square bar shall meet those specified in Table 2.

Foreword i
1 Scope
2 Normative references
3 Terms and definitions
5 Dimensions and tolerances
6 Shape
7 Weight
Annex A (Informative) Density of titanium and titanium alloy