该产品是在导入ISO规格之后按照JIS标准所生产，用于检查不要求密封性的机械连接为主要目的的螺纹。和遗忘的管用平行螺纹量规的相差点如下：使用方法为：界限螺纹量规的通规可依轻松的穿过止规的    螺纹拧进不到2圈的话，这样测量等级则是合格的。

      Pipe with parallel thread coming under the ISO standard,where the main purpose is liquids but a tight mechanical.Connection is not requied,is inspected using a  parallel limit Gauge (G).This includes such items as pipe connections.Plumbingparts and equipment to handle liquids.

（1） 等级的有无

● 内螺纹用的螺纹量规等级是没有的。

● 外螺纹用的螺纹量规区分为A级和B级，只要GR是A级B级共用的，

Tolerance class on thread plug gauges is unspecified.

However there are two classes (A and B) for thread ring gauges.The GR(GO) is commonly used for the A and B classes.

（2） 通端和止端没有检查用和加工用的区别

               Go and not go of the ISO gauge system is made with same dimentions for both inspection and working.

（3） 判定螺纹环规是否合格。

               GR、NR等，根据通规或止规两端的插头（GRGF,GRNF,NRGF,NRNF）来检查。

               For the ISO class gauge system,the thread gauge for check fitting of the thread ring gauge is the GO and NOT GO limit type.

（4） 磨损点检查的插头。

       NR用的磨损点检塞规(NW)是新导入的。

                New barjone wear check plug for NOT GO thread ring gauge.