內螺紋接頭螺紋公差等級
內螺紋接頭螺紋公差等級對照表，一般常見的公差等級為6g和6h，可以透過相對應的環規檢驗。
| Thread tolerance classes of internally threaded adaptors | ||
|---|---|---|
| Finsh of fastener | Thread tolerance class | |
| Thread tolerance class of fastener before any surface coating | Thread tolerance classe of internally threaded adaptor | |
| As processed | 6h or 6g | 6H |
| Electroplating to ISO 4042 | 6g or 6e or 6f | 6H |
| Zinc flake coating to ISO 10683 | 6g or 6e or 6f | 6H |
| Hot dip galvanizing to ISO 10684 in order to mate with nuts tapped to thread tolerance classes: －6H －6AZ －6AX | 6az 6g or 6h 6g or 6h | 6H 6AZ 6AX |