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1. Objective 目的
Provide detail information for every step about how to perform the test about the tapered male
thread.
Standardize the actions of the inspectors and clarify the determining way in different conditions of
the test.
就如何检验锥形内螺纹提供详细的各步骤说明. 规范检验人员动作及阐明各种情形
下的判断方法．
2. Scope 范围
It is applicable for all the female tapered threads such as NPT,BSPT etc.
适用于所有锥形内螺纹，比如ＮＰＴ，ＢＳＰＴ等．
3. Definitions 定义
3.1 Thread螺纹
There are two main types of threads ud prently around the world, one being a normal
straight thread and the other is tapered thread. Tapered threads are ud when pressure tight
joint are made on the threads. Straight thread is only otherwi. Tapered thread is also known as
conical thread.The angle of the tapered thread is 1˚47’. NPT and BSPT are tapered threads
mostly ud whin the faucet industry.
目前世界上主要有两种螺纹．一种是平形螺纹，另一种是锥形螺纹．锥形螺纹主
垃圾分类处理要用于压力密封连接上．而平形螺纹则用于其它方面．锥形螺纹锥度为
三阿哥1˚47’．NPT和ＢＳＰＴ是两种主要用于水龙头行业的锥形螺纹
NPT: National Pipe Tapered；The angle of thread is 60˚.美标管锥螺纹，牙形角60˚．
BSPT: British Standard Pipe Tapered;The angle of thread is 55˚．英标管锥螺纹，牙形角
55˚.
3.2 Plug Gauge 塞规
女孩名子
Thread plug gauge is the tool for an all-around checking about the female threads which with the
male threads.
螺纹塞规是一个对内螺纹进行全面综合检查的一个工具．
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3.3 Accuracy class 精度等级
There are 3 accuracy class for American Standard thread in inch unit. The class 2 is the most
wildly ud one. The class 3 is only for exact industry. The class 1 is for the loo match, while
there is only one accuracy class for R in DIN.
对于美标的英制螺纹有三个精度等级．等级２应用的最广泛，等级３则一般用于
精工，等级１则适用于非常松的允差配合．而ＤＩＮ标准的R螺纹则只有一个精霜降手抄报图片
度等级.
3.4 Standard 标准
The DIN R thread gauges are designed for Parallel / Tapered Match System. So must be careful
陈笑波to choo the right gauge marked with DIN. The manufacturer and the clients should u the
gauge following the same standard.
对于ＤＩＮ标准的Ｒ螺纹量规是为柱／锥配合体系设计的，选择量具时请注意量
具上应有ＤＩＮ标记．生产商和客户应当使用同一标准下的量规.
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4 Tools 工具
4.1 Plug Gauge 塞规
First choo the correct matched plug gauge according to the thread standard and specification of the product. Becau different standards specify thread per inch, angle of thread, roots, crests, truncations and many others differently.
首先根据产品螺纹的种类及规格选择匹配的塞规．因为不同种类螺纹的牙数，牙形角，齿顶，齿跟等都不相同．
The plug gauge for tapered thread has three surfaces.The number 1 surface is the low limit and the number 3 surface is the up limit. The number 2 surface is the ba level.
检验锥形螺纹的塞规有三个面．１号面是下限，３号面是上限．而２号面是基面．
Accuracy class: 2B (NPT) 精度等级: 2B (NPT)
Standard:
ISO7-2:2000/Nch1594-1-1979/DIN(BSPT); ANSI(NPT) 标准:ISO7-2:2000/Nch1594-1-1979/ DIN (BSPT);ANSI(NPT)
Symbol of BSPT: R BSPT 代号: R
Symbol of NPT: NPT / Z NPT 代号: NPT / Z
4.2 Calliper 卡尺
The specification of the calliper should cover the range of the thread length.
卡尺的量程应足够可测量螺纹长度
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葡萄树简笔画5 Instructions步骤
Step 1 : Turn lightly the plug gauge into the product completely. No extrusion.No distortion. 步骤１：轻轻将塞规旋入产品内．不可挤压，不允许有变形.
Determine判断: You can't turn more even by small force (No distortion) .This status means the fitting threads already at the end position.
当你用很小的力（没有产生变形）不能继续旋进螺纹时则螺纹已经旋到底了
Step 2: Check the relative position of the thread of product to the surface of the gauge.
步骤２：检查产品螺纹与塞规各面的相对位置．
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OK
3# can be accepted too, but can’t be accepted if the same level to 1# surface.
产品螺纹的位置必须在环规的１号面和３号面之间．可以和3号面相平但不可与
塔式起重机1号面相平
努力工作英语Step步骤 3 : Check the uful length＂L" of the thread by calliper．
用卡尺测量螺纹的有效长度．
Specification R3/8 R1/2 R3/4 R1 R1 1/4 R1 1/2 R2
L Min 7 9.1 10.2 11.6 13.4 13.4 16.9 Determine判断:The uful length of the thread should meet the requirements of the table
attached.
螺纹的有效长度需符合上表的要求．
