As different of each product Application , its processing technology and raw material quality requirements are also different.Stainless steel products in general, the required raw material thickness tolerance is also each are not identical, like the 2 kinds of tableware and vacuum cup, etc., general demand is higher, the thickness tolerance - 3 ~ 5%, and the type of tableware thickness tolerance general requirements - 5%, steel pipe class requirements - 10%, hotel with freezers material thickness tolerance requirements of 8%, dealer requirement for thickness tolerance is in commonly between - 4% ~ 4%.At the same time, the difference in the product's internal and external sales will also lead to the difference in the thickness tolerance requirements of the customer.Generally, the thickness tolerance requirements of the customers of export products are relatively high, while the thickness tolerance requirements of domestic enterprises are relatively low (mostly due to cost considerations), and some customers even require -15%.
Besides DDQ (deep drawing quality) material, it refers to the material used for deep drawing (punching), also known as soft material. This kind of material is mainly characterized by high elongation rate (53%), low hardness (170%) and internal grain grade between 7.0 and 8.0, with excellent deep-drawing performance.Many enterprises producing heat insulation bottles and POTS have higher processing ratio (BLANKING SIZE/ product diameter), and their processing ratio reaches 3.0, 1.96, 2.13 and 1.98 respectively.SUS304DDQ material is mainly used for these products with high processing ratio. Of course, products with processing ratio over 2.0 generally need several stretches to complete.If the extension of raw materials cannot be achieved, the product will easily crack and pull through during the processing of deep drawing products, which will affect the qualified rate of finished products, and of course increase the cost of the manufacturer.
(2) the general material: mainly used for materials, except for DDQ USES the characteristics of this material is relatively low elongation (≧ 45%), and relatively high hardness (≦ 180 hb), internal grain size grade between 8.0 ~ 9.0, compared with DDQ material, its deep drawing performance is relatively a bit poor, it is mainly used to do not need to stretch to get the goods, as a kind of spoon, spoon and fork cutlery, electrical appliances, such as steel pipe used.However, compared with DDQ material, it has an advantage of relatively good BQ property, which is mainly due to its slightly higher hardness.
Stainless steel sheet is a kind of material with low price, but the customer demands very high quality of its surface.Stainless sheet in the process of production inevitably appear all sorts of defects, such as scratches, pitting, sand hole, wiring, crease, pollution, etc., and its surface quality, like these defects such as scratch and crease is not allowed, senior material and pitting, sand hole defects in the spoon, spoon, fork, production is not allowed, because the polishing is very difficult to sell it.It is necessary to determine the surface quality grade and product grade according to the degree and frequency of various defects on the surface.