What are the requirements for dimension and manufacturing tolerance of die steel? Pay attention to the reasonable tolerance and dimensional requirements of die steel materials, which can bring convenience to die manufacturing, improve economic efficiency and reduce waste products during manufacturing. No matter what kind of material, high-precision dimensions of plastic parts are required. What are the requirements for die steel dimensions and manufacturing tolerances? Next, Jinan die steel Xiaobian tells you.

模具钢的尺寸：

Dimensions of die steel:

根据塑料△VS值，将各种塑料的收缩特性分为4个组。△VS值小的组是高精度组，以此类推，△VS值大的组为低精度组。并按照基本尺寸编制了精密技术、110、120、130、140、150和160公差组。并规定，用收缩特性稳定的塑料成形塑件的尺寸公差可选用110、120和130组。用收缩特性中等稳定的塑料成形塑件的尺寸公差选用120、130和140。如果用这类塑料成形塑件的尺寸公差选用110组时，即可能出大量尺寸超差塑件。用收缩特性较差的塑料成形塑件的尺寸公差选用130、140和150组。

According to the △ vs value of plastics, the shrinkage characteristics of various plastics are divided into four groups. The group with small △ vs value is the high-precision group, and so on. The group with large △ vs value is the low-precision group. Precision technology, 110, 120, 130, 140, 150 and 160 tolerance groups are compiled according to the basic dimensions. It is also stipulated that 110, 120 and 130 groups can be selected for the dimensional tolerance of plastic parts formed with plastics with stable shrinkage characteristics. The dimensional tolerances of plastic parts formed with plastics with moderate and stable shrinkage characteristics are 120, 130 and 140. If 110 groups are selected for the dimensional tolerance of plastic parts formed with this kind of plastic, a large number of plastic parts with out of tolerance can be produced. The dimensional tolerances of plastic parts formed with plastics with poor shrinkage characteristics are 130, 140 and 150 groups.

模具型腔和型芯的加工尺寸除了通过D=M(1+S)公式计算基本尺寸之外，还有一个加工公差的问题。按照惯例，模具的加工公差为塑件公差的1/3。但由於塑料收缩率范围和稳定性各有差异，一定合理化确定不同塑料所成形塑件的尺寸公差。即由收缩率范围较大或收缩率稳定较差塑料成形塑件的尺寸公差应取得大一些。否则就可能出现大量尺寸超差的废品。

In addition to calculating the basic dimensions through the formula d = m (1 + s), there is also a problem of machining tolerance. According to the Convention, the machining tolerance of the die is 1 / 3 of the tolerance of the plastic part. However, due to the differences of plastic shrinkage range and stability, the dimensional tolerance of plastic parts formed by different plastics must be reasonably determined first. That is, the dimensional tolerance of plastic parts formed by plastic with large shrinkage range or poor shrinkage stability should be larger. Otherwise, a large number of waste products with out of tolerance may appear.

为此，各国对塑料件的尺寸公差专门制订了标准或行业标准。也曾制订了部级标准。但大都无相应的模具型腔的尺寸公差。德国标准中专门制订了塑件尺寸公差的DIN16901标准及相应的模具型腔尺寸公差的DIN16749标准。

Therefore, countries have formulated national standards or industrial standards for the dimensional tolerance of plastic parts. China has also formulated ministerial professional standards. But most of them have no corresponding dimensional tolerance of die cavity. Din 16901 standard for dimensional tolerance of plastic parts and DIN 16749 standard for dimensional tolerance of die cavity are specially formulated in German national standards.