STANDARD TOLERANCE CHART ISO
Please click here to see the ISO 8062 1994 millimeter (mm). The following is the ISO 8062 1994 inches and SFSA 2000 standard. Some level of deviation is inevitable although we also try our best to control the deviation as small as possible. Sometimes, too strict requirements are not realistic. Any small factor may cause the deviation of dimensions. The deviation of rough casting dimensions are related with the strength of molding sand, compactness of sand mold, liquid iron temperature, chemical components, moisture of sand and workers’ operation. Then the foundries should consider it, and can try to meet the special tolerance by grinding or machining. Sometimes, as for some mounting dimensions, the clients will have special requirements. However, this standard can not represent all dimensions. The manual green sand casting can reach CT10 to CT12 degree. The resin sand casting can reach CT9 to CT10 degree. The machine molding and automatic molding can reach CT9 degree. The highest tolerance for sand casting is 8-10 degree, which means shell molding process can reach CT8 degree. From these two standards, you can see that investment casting is 5-7 degree. In addition, please see the following standard SFSA 2000, although this standard is for steel castings, it is also suitable for iron castings.Īctually, we also have Chinese standard, which is as same as the description in this SFSA 2000. Please see the following standard BS6615:1996, this standard is also as same as ISO 8062:1994, which has been taken as the standard for the rough castings. According to our experience, the standard of BS6615:1996 and SFSA 2000 can be used for solving this issue. Figure below shows a chart, to be used as a general guide. EN 572 is a normative standard for base glass. Tolerance is the total amount a specific dimension can vary.
STANDARD TOLERANCE CHART HOW TO
Sometimes, our clients will be wondered how to determine the rough casting tolerance. Standard tolerances - Standard tolerances are tolerances that can be ensured during the normal course of production Special tolerances - Special tolerances can be realised during production with additional precautionary measures and must be agreed upon on a case-by-case basis Base glass.