GB/T 3325-2024General technical requirements for metal furniture (English PDF)

6.2 Determination of shape and position tolerances

6.2.1 Vertical degree of adjoining side Use a steel tape measure or steel ruler with an accuracy of not less than Class II to measure the lengths of the two diagonals and opposite sides of a rectangular plate or frame. The difference between these measurements is the measured value of the vertical degree of adjoining side.

6.2.2 Warpage Use a warpage measuring instrument with an accuracy of not less than

0.1 mm; select the plate with the most severe warpage; place the instrument on the diagonal of the plate for measurement; take the maximum distance as the measured value of the warpage.

6.2.3 Tabletop plane deviation Use a steel tape measure or steel ruler with an accuracy of not less than Class II to measure the height of the midpoint of each pair of opposite sides of a rectangular tabletop from the ground; for a circular tabletop, measure the height of the highest point on the circumference and another point symmetrical to the center of the circle from the ground. The ratio of the difference to the side length or diameter is the evaluated value of the plane deviation.

6.2.4 Level degree Use a level degree measuring instrument with an accuracy of not less than

0.01 mm; select the three plates with the most severe unevenness and measure the distance between the plate within a length of 0 mm ~ 150 mm on its surface and the reference straight line; take the maximum distance as the measured value of the level degree.

6.2.5 Circular degree Use a caliper with an accuracy of not less than

0.05 mm to measure the maximum and minimum pipe diameters at the midpoint of the curved section of the round pipe; take the difference as the evaluated value of the circular degree.

6.2.6 Place difference degree When using a place difference degree measuring instrument with an accuracy of not less than

0.1 mm, the measurement shall be performed at the point where the distance between two adjacent surfaces of the door and frame, or between doors, or of the door and drawer, or between drawers is the largest. Select one of these adjacent surfaces as the measurement reference surface; place the reference surface of the instrument on the measurement reference surface; use the measuring surface of the instrument to measure the other adjacent surface; then measure one or more points along the adjacent surface. When the measured values are both positive or negative, take the largest absolute value as the evaluated value of the place difference degree; when the measured values are positive and negative, take the sum of the largest absolute values of the measured values as the measured value of the place difference degree, and the largest measured value as the evaluated value of the place difference degree.

6.2.7 Gap Use a feeler gauge with an accuracy of not less than

0.01 mm to measure. Before measuring, open and close the drawer or door three times to ensure that the drawer or door is in the closed position. When measuring drawer gaps, the drawer shall be placed close to one side, and the maximum gap on the other side shall be measured. When measuring door gaps, the part with the largest gap shall be measured, and the maximum value shall be used as the evaluated value of the gap.

6.2.8 Extension element Use a steel tape measure or steel ruler with an accuracy of not less than Class II to measure. During the measurement, place the steel ruler on the horizontal plane or side adjacent to the measurement part of the test piece. When the test piece is extended by two-thirds of its total length, measure the free drop of the horizontal edge of the drawer or the left and right swing of the drawer side. Take the maximum measured value as the evaluated value of droop and swing.

6.2.9 Stability of the foot landing Place the test piece on a flat plate or a flat surface, with three feet on the ground. Use a feeler gauge with an accuracy of not less than

0.01 mm to measure the distance between the other foot and the plate.

6.3 Determination of appearance performance

6.3.1 Discoloration, fading Inspect three locations on the outward appearance or interior of the product. Use a damp, degreased white gauze to rub each location back and forth three times with appropriate force. The rubbing distance shall be 200 mm ~ 300 mm. Observe whether the gauze has the color from the coated area.

6.3.2 Wood infestation inspection Use visual inspection to carefully examine the wood material for live insects, eggs, or insect-eaten powder.

6.3.3 Others Under natural light or near-natural light with an illuminance of 300 lx~600 lx, and at a viewing distance of 700 mm~1 000 mm, conduct the test jointly by three people, and take the majority of identical conclusions as the test result.