QC/T 350-2023Plastic split dowel (English PDF)

4.1 General

4.1.1 The casting aluminium pistons (hereinafter referred to as the “pistons”) shall be manufactured in accordance with product drawings and technical documents approved through the prescribed procedures.

4.1.2 In addition to meeting the following technical requirements, the remaining technical

requirements for pistons shall comply with the provisions of GB/T 1148.

4.1.3 The technical requirements for casting aluminium pistons with ring carrier shall be implemented according to QC/T 283.

4.2 Materials

4.2.1 Material composition

The piston body is made of cast aluminum-silicon alloy. The material grade or composition shall be specified in the product drawings.

4.2.2 Mechanical properties and stability of volume

4.2.2.1 The piston shall be heat-treated, and its mechanical properties and stability of volume (residual expansion of piston diameter D) shall meet the requirements of Table 1.

4.2.2.2 The hardness difference of the same piston shall be less than or equal to 10 Brinell hardness units, and the hardness difference of pistons in the same batch shall be less than or equal to 30 Brinell hardness units.

4.2.3 Metallographic structure

The metallographic structure shall meet the requirements of QC/T 553.

specifications.

4.9.3 The printing markings for product mass grouping shall conform to the product drawing specifications.

4.10 Piston Cleanliness

Piston cleanliness shall meet the requirements of JB/T 14615.

7.1 Marking

7.1.1 Each product package shall be marked with, but is not limited to, the following.

a) Manufacturing enterprise’s name code or trademark;

b) Specification marking and dimension group code;

c) Mass or mass group code;

d) Ex-factory serial number, batch number, or manufacturing date (may also be noted on the certificate of conformity);

e) Orientation markings for piston installation (for pistons with asymmetrical structures).

7.1.2 Markings shall be permanent. The location, dimensions, and method of marking shall conform to the product drawing specifications, but shall not damage the product or affect its use.

7.1.3 The packaging box shall indicate, but is not limited to, the following.

a) Manufacturing enterprise’s name, trademark, and address;

b) Product name, model, and part number;

c) Dimension group code;

d) Mass or mass group code;

e) Quantity;

f) Executive standard number;

g) Quality certification marking;

h) Packaging date.

7.2 Packaging

7.2.1 Each piston must be cleaned and treated with anti-corrosion measures before packaging.

Each piston shall be wrapped in moisture-proof and corrosion-resistant materials before being placed in a packaging box to ensure that it is not damaged during normal transportation.

7.2.2 Each packaging box shall contain pistons of the same model, dimension group, and mass group.

7.2.3 Each packaging box shall include a product certificate of conformity signed and stamped by the inspector of the manufacturing enterprise’s inspection department.

7.2.4 Packaged pistons shall be placed in cardboard boxes or dedicated wooden crates, with double-layered waterproof paper lining the inside. The total mass of the boxes shall not exceed

50 kg.

7.2.5 If the user has special requirements, those requirements shall be followed.

......