GB/T 15763.2-2025Safety glazing materials in building - Part 2: Tempered glass (English PDF)

5.1 Dimensions and Tolerances

5.1.1 The tolerances for the side lengths of rectangular flat tempered glass shall comply with the provisions of Table 1. Table 1 -- Tolerances for Side Lengths of Rectangular Flat Tempered Glass and Straight Edge Lengths of Curved Tempered Glass peeling on the surface and edges of the sample after the test is not considered damage.

6.1 Dimensions and Tolerances

6.1.1 Side length, arc length and straight edge length Use a steel ruler or steel tape measure with a graduation value of 1 mm to measure the lengths of each side of the rectangular flat tempered glass, or the arc edges and straight edges of the curved tempered glass. The difference between the actual measured value and the nominal value is the tolerance.

6.1.2 Diagonal difference Use a steel ruler or steel tape measure with a graduation value of 1 mm to measure the length of the two diagonals of the rectangular flat tempered glass and calculate the absolute value of the difference.

6.1.3 Conformity Use a feeler gauge or a steel ruler with a graduation value of

0.5 mm to measure the gap between the glass and the standard sample or mold along the edge of the curved tempered glass and perpendicular to the dry glass surface. The conformity of the curved tempered glass is the maximum gap measurement.

6.1.4 Thickness tolerance Measure with an outside micrometer with a graduation value of

0.01 mm or an instrument of equivalent precision. For rectangular products, the measurement is at the midpoint of the four sides within 15 mm from the edge of the glass plate; for products of other shapes, the measurement points are agreed upon by both the supply and demand sides. Take the arithmetic mean of the measured values, and the difference between the mean and the nominal thickness is the thickness tolerance. Values are rounded to 2 decimal places.

6.2 Edge Processing Visually inspect the shape and quality of tempered glass edge processing.

6.3 Circular Holes Use a vernier caliper with a graduation value of

0.02 mm or an instrument of equivalent precision to measure the hole diameter. Measure once in each perpendicular direction. Calculate the difference between the two measured values and the nominal value of the hole diameter. The tolerance with the largest absolute value of the difference is the tolerance for hole diameters. Use a steel ruler or steel tape measure with a graduation value of 1 mm to measure the position of the circular hole, the shortest distance from the edge of the inner diameter of the circular hole 2 -- Support plate; 3 -- Sample; 4 -- Flat support table. Figure 15 -- Schematic Diagram of the Fragmentation Pattern Test of Curved Tempered Glass

6.10 Impact Performance of Shot Bag

6.10.1 Samples The sample is a flat test piece with dimensions of 1 930 mm 864 mm that is of the same thickness, same type and manufactured under the same process conditions as the product.

6.10.2 Test equipment The test device shall comply with the provisions of Appendix F.

6.10.3 Test steps

6.10.3.1 Use a flexible steel wire rope to lift the impactor vertically and let it hang down naturally, so that the outer circumference of the largest diameter part of the impactor's cross- section is no more than 13 mm from the surface of the sample and within 50 mm from the center of the sample.

6.10.3.2 Lift the impactor so that the center position of the maximum diameter of the impactor remains at a drop height of 300 mm. Release the impactor with an initial velocity of zero, swing freely and fall, impacting once near the center point of the sample. If the sample is not damaged, raise it to 750 mm and impact again near the center point of the same sample.

6.10.3.3 When the sample is still intact, raise it to a height of 1 200 mm and impact once near the center point of the same sample. Before each impact test, the impactor shall be raised to the corresponding height and kept stationary. At this impact height, the central axis of the metal rod of the impactor shall be in a straight line with the suspension rope of the impactor, and the steel wire rope shall be in a taut state.

6.10.3.4 When the drop height is 300 mm, 750 mm or 1 200 mm, when the sample is damaged, within 5 min after the destruction, select the 10 largest glass fragments without penetrating cracks, weigh their mass, and measure the length of the longest glass fragment without penetrating cracks remaining on the frame. The length of the part pressed inside the frame is not counted.