GB/T 17340-1998Road vehicles. Safety glasses. Dimensions, shapes and appearances (English PDF)

3.1 Curve part. Part R in Figure 1 (the end point of Part R in Figure 1 is included in the

curve part).

3.2 Design line. the reference line drawn on the test sample frame.

3.3 Reference edge. A predetermined edge on the glass, usually the longest edge.

3.4 Reference edge deviation. the deviation between the reference edge of the glass

and the design line (see A in Figure 1).

3.7 Curve part deviation. the deviation between the glass curve part and the design

line (see D in Figure 1).

Other terms in this Standard are consistent with JC/T 632.

5.1 Dimension deviation

The dimension deviation of flat products and single-curved glass shall comply with the

provisions of Table 2; the dimension deviation of complex-curved glass shall comply

with the provisions of Table 3.

5.2 Curvature and goodness of fit

5.2.1 The curvature of flat products shall comply with the provisions of Table 4.When

the length-width ratio of the product is greater than 3.1, the curvature shall be agreed

Unit. mm

5.2.3 The goodness of fit for the complex-curved glass shall comply with the provisions

of Table 6.

6.1 Appearance quality

The appearance quality of the products shall comply with the provisions of Table 7.

7.1 Dimension deviation

7.1.1 When inspecting the dimension deviation of flat products, the products shall be

placed horizontally on the test sample frame; so that it is close to one side (corner) of

the sample frame, and then measure the gap between the products and the edge of

the sample frame from the opposite edge (corner) by a feeler.

7.2 Curvature

When measuring the curvature of a flat product, place it vertically and use a steel ruler

to measure it horizontally close to the glass surface. When it is in arc shape, it shall be

expressed by the percentage of the arc height divided by the chord length.

7.3 Goodness of fit

When measuring the goodness of fit for the curved product, place the product

according to the inspection state in 7.1.2; and use a feeler to measure the maximum

gap between the product and the test sample frame.

7.4 Appearance quality

The general appearance defects are visually inspected; observe at a distance of

500mm from the sample glass against the uniformly illuminated ground glass

background; and use more than 300 lx of white light to penetrate behind the ground

glass. Avoid direct sunlight on the sample glass during inspection.

8.1 Sampling and batching rules

8.2 Judgment rules

In a batch of glass samples, if the unqualified number is equal to or greater than the

unqualified number in Table 9 or 10, the dimensional deviation and appearance quality

of this batch of products shall be deemed not to meet the requirements.

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