Dimensional Accuracy And Surface Quality Grade Of Zinc Alloy Die Castings

Zinc alloy die-casting technology is widely used in injection molding process. Its main advantage is to pay attention to improving the quality of castings.

Everyone who knows about zinc alloy die casting knows that the runner and residual materials are part of the casting. They have little value in the casting, but they are still included in the casting cost. At the same time, the alloy is recyclable. Generally, these surplus materials will be returned to the original supplier in exchange for new materials. In this guide, we focus on talking about the dimensional accuracy and surface quality grade of zinc die castings.

Generally, the precision of die castings is it13; High precision die castings are it11 grade. Current tolerance grade of zinc alloy die castings ct:4-6. The dimensional classification of precision die castings is considered from three aspects: the rationality of product drawing requirements, the possibility of die-casting technology assurance, and the economy of mass production. The dimensional tolerances are selected from the whole process of die-casting blanks to finished parts. It is generally believed that precision die castings should also be classified into three types, namely, general dimension, strict dimension, and high-precision dimension, for various dimensions on the same casting according to the different numerical levels of dimensional tolerance achieved by die casting.

Zinc Alloy Die Castings Dimensional Accuracy

Dimensional tolerance values of castings gb/t6414 – 1997, is08062:1994

Basic dimensions of castings – tolerance class (mm)

CT4 – CT5 – CT6

10~16 – 0.28 – 0.38 – 0.54

16~25 – 0.30 – 0.42 – 0.58

25~40 – 0.32 – 0.46 – 0.64

40~63 – 0.36 – 0.50 – 0.70

63~100 – 0.40 – 0.56 – 0.78

100~160 – 0.44 – 0.62 – 0.88

160~250 – 0.50 – 0.70 – 1.0

250~400 – 0.56 – 0.78 – 1.2

zinc Alloy Die Castings Surface Quality Grade

Die castings are divided into 3 categories according to the use requirements. Surface texture 1 Classification gb/t13821 – 92

level – Scope of use – Remarks

Level 1 – Surfaces with high requirements, chrome plating, polishing, grinding, relative motion mating surfaces, surfaces in hazardous stress areas – equivalent to RA 1.6 μ m

Level 2 – Surfaces with general painting requirements or sealing requirements, galvanized, anodized, painted, non greasy, assembly contact surface – equivalent to RA 3.2 μ m

Level 3 – Protective painted surfaces and fastening contact surfaces, greasy paint surfaces, other surfaces – equivalent to RA 6.3 μ m