(1) Material.

① DDQ (deep drawing quality) material: refers to the material used for deep drawing (punching) purposes, which is what we call soft material, the main characteristics of this material is a higher elongation (≧ 53%), lower hardness (≦ 170%), the internal grain grade between 7.0 ~ 8.0, deep punching performance is excellent. At present, many production of thermos bottles, pots and pans, the processing ratio of its products (BLANKING SIZE / product diameter) are generally higher, their processing ratio of 3.0, 1.96, 2.13, 1.98. SUS304 DDQ with material is mainly used for these requirements of higher processing ratio of products, of course, processing ratio of more than 2.0 products are generally required after several times of stretching to complete. If the extension of raw materials can not reach, in the processing of deep-drawn products, the product is very easy to produce cracks, pull through the phenomenon, affecting the finished product qualified rate, of course, also increased the cost of manufacturers.

② General material is mainly used in addition to DDQ use of materials, this material is characterised by relatively low elongation (≧ 45%), and relatively high hardness (≦ 180), internal grain size grade in 8.0 ~ 9.0, and DDQ with the material, it is relatively poor deep punching performance, it is mainly used without stretching can be obtained products, such as a class of tableware spoons, spoons, forks, electrical appliances, steel pipes It is mainly used for products that can be obtained without stretching, such as spoons, spoons, forks, electrical appliances, steel pipes etc. However, it has an advantage over DDQ material in that BQ is relatively good, mainly due to its slightly higher hardness.

(2) Surface quality.

Stainless steel sheet is a very high priced material, and customers demand very high surface quality from it. But stainless steel sheet in the production process will inevitably appear a variety of defects, such as scratches, pockmarks, creases, pollution, etc., and thus its surface quality, such as scratches, creases and other such defects are not allowed to appear whether it is senior material or low grade, and pockmarks such defects in the spoon, spoon, fork, production is also never allowed, because polishing is difficult to throw off it. We determine the surface quality level according to the degree and frequency of various defects on the surface, so as to determine the product level.

(3) Thickness tolerance.

Generally speaking, the different stainless steel products, the requirements of the material thickness tolerance also varies, such as two types of tableware and insulation cups, etc., the thickness tolerance is generally required to be higher, -3 ~ 5%, while a class of tableware thickness tolerance is generally required - 5%, steel pipe type requirements - 10%, the hotel with the thickness tolerance of cold cabinet material requirements for - 8%, the dealer requirements for thickness tolerance is generally between -4% to 6%. At the same time, the difference between domestic and foreign sales of products will also lead to different requirements of customers on the thickness tolerance of raw materials. General export products customer thickness tolerance requirements are higher, while the domestic sales enterprises on the thickness tolerance requirements are relatively low (mostly for cost considerations), some customers even require -15%.

(4) Weldability.

Product use of different welding performance requirements are also different. A class of tableware on the welding performance generally do not require, even including some of the pot enterprises. But the vast majority of products need raw materials welding performance is good, like the second class tableware, insulation cups, steel pipes, water heaters, drinking fountains, etc..

(5) Corrosion resistance

The vast majority of stainless steel products require good corrosion resistance, such as one or two types of tableware, kitchenware, water heaters, drinking fountains, etc. Some foreign businessmen also do corrosion resistance tests on their products: NACL aqueous solution heated to boiling, pour off the solution after a period of time, wash and dry, weigh the loss, to determine the degree of corrosion (Note: the product polishing, because of the composition of the sand cloth or sandpaper containing Fe, will lead to test (Note: when the product polishing, because the sand cloth or sandpaper contains Fe, will lead to test surface rust spots)

(6) Polishing performance (BQ sex).

At present, stainless steel products are generally polished during the production process, only a few products such as water heaters, drinking fountains, etc. do not need to be polished. Therefore, this requires a good polishing performance of raw materials. The main factors affecting the polishing performance are the following.

① raw material surface defects. Such as scratches, pockmarks, over acid washing, etc..

② raw material material problems. Hardness is too low, polishing is not easy to polish bright (BQ sex is not good), and hardness is too low, in deep drawing when the surface is easy to appear orange peel phenomenon, thus affecting the BQ sex. A high hardness has a relatively good BQ.

③ After deep drawing of the product, the surface of the area with great deformation will also have small black spots and RIDGING, which will affect the BQ property.