NPT与NPTF的区别？
还有１／２ＮＰＴＦ的牙数是多少？谢谢！ 请看附件NPT是美标锥形密封螺纹
NPTF是美标锥形干密封螺纹
牙数14牙 楼上正确
NPT是指普通螺纹，密封性差一点
NPTF是干密封螺纹，二者差异很小
后者的精度等级要高很多
一般不用。
前者用处多一些，所谓的锥形是指外螺纹小径按一定锥度变大。外径和P不变的
内螺纹恰恰相反！ 好東西 塊來瞧瞧 why why why位蛇ㄇ沒法變髮 下載嗎是我哪裡怪ㄌ媽 NPT Vs. NPTF Taper Pipe Threads
The two most common taper pipe threads used in the United States are NPT and NPTF. Applications range from electrical conduits and hand railings to high-pressure pipe lines that carry gas or caustic fluids. NPT threads are for mechanical or low-pressure air or fluid applications and require the use of sealing compounds like Teflon tape, to provide the seal. When the application is more critical, and the sealing compound may fail due to high heat or pressure, NPTF Dryseal threads are used. This mechanical seal is produced by the mating and slight crushing of the threads when a wrench is applied to tighten the fittings.
NPT和NPTF螺纹是两种美国最常用的锥管螺纹。应用范围从电线管道和扶手到运送煤气或腐蚀性液体的高压管线。NPT用于机械的或者低压的气体和液体，要求使用密封剂来保证密封。当密封要求严格时，密封剂可能由于高温高压会失效，这时可以采用NPTF干密封螺纹。当用扳手上紧配件时，这种机械密封会在螺纹配合和轻微的变形来生成密封效果。
Visually, both threads appear to be identical. Both have a ¾” taper over one foot of length. Both have the same pitch diameter at the top of the hole of internal threads or end of the pipe on external threads, and both have the same thread lengths or depths. However, there is a subtle difference in the thread form that differentiates the two. The major and minor diameters of both threads differ slightly. With NPT threads, after a wrench is applied, slight spaces at the major and minor diameters may exist that would allow the assembly to leak and therefore a sealing compound is used to fill any gaps. On the other hand, NPTF threads are designed to ensure that sufficient crushing of the entire thread form will take place to produce a mechanical seal.
这两种螺纹在目测时是相同的。两种在一英尺的长度上都有3/4的锥度。在内螺纹的孔的顶端或者外螺纹的管的端部拥有相同的中径，而且拥有相同的螺纹长度和深度。尽管如此，在螺纹牙型上还是有细微的差别。两螺纹的大直径和小直径上有细微的差别。对于NPT螺纹，使用扳手上紧后，在大直径和小直径上可能允许装配后漏气，因此会使用密封剂来填充所有的间隙。另一方面，NPTF螺纹的设计用于保证在整个牙形上产生足够的变形以生成这种机械密封。
How does the difference in thread forms effect the tooling used to produce NPT and NPTF threads? Taps are available for both NPT and NPTF threads having the appropriate form to produce each type of thread. Since NPT threaded parts require sealing compounds, it is acceptable to use an NPTF tap for NPT applications. However, NPT taps cannot be used for NPTF applications, as it will likely produce a thread that will leak. The same is true of external threads. In most cases the tap drill is the same for both forms.
牙型的不同如何影响使用的工具来生产NPT和NPTF螺纹？NPT和NPTF螺纹牙形都是采用丝锥来生产每种螺纹。因为NPT螺纹零件要求密封剂，用NPTF丝锥在攻NPT螺纹是可以接受的。但是NPT丝锥不能用于NPTF螺纹，因为它生产的螺纹会漏气。
The most significant difference in the two threads is the inspection required. Since sealing compounds will be used for NPT threads, only a single plug with a step, known as an L1 plug (internal thread) or a single thin L1 ring (external) are required to check size. However, since the taper and the position of major and minor diameters are so critical to the sealing of NPTF threads, the additional threads in the assembly known as L2 and L3, and the major and minor diameters are inspected with either special plug or ring gages.
最大的不同是这两种螺纹的检查要求。因为NPT螺纹要使用密封剂，只要用一个塞规，大家叫L1规（内螺纹）或L1环规（外螺纹）来检查尺寸。但是，因为锥度和大直径，小直径对NPTF螺纹的密封很重要，因此要求其他的螺纹验规L2和L3规，大直径和小直径要用特殊的塞规或环规来检验。 why why why
why why why位蛇ㄇ沒法變髮 下載嗎是我哪裡怪ㄌ媽 幫幫我吧 大大 请问一楼，我下载了你的东西非常好，想请教你个问题：《公英制连接螺纹标准手册》是整本书，是扫描的吗？还是用什么方法制作成.pdf文档的，我借了本参考书，想把它转换成.pdf的，好整理，也好打印，复印太麻烦了。
有谁能帮我？ 更正一下，NPTF还到处听说那个是F是female的意思，也就是我们常说的母扣，我们定料货单上也写的也是NPTF也就是female 的意思，糊涂了 NPT螺纹的内螺纹和外螺纹中径、大径是间隙配合,
NPTF螺纹的内螺纹和外螺纹中径和大径是过盈配合 一直对这个不是太清楚，终于明白了，谢谢各位 NPT在不是需要很严格密封的场合，比如毒气等应用时，如果温度比较高，PTFE等没办法使用的情况下世可以不加密封填料的吧
不知6楼的资料来自何处阿 1、区别：NPT是一般用途的美国标准锥管螺纹；NPTF是干密封式美国标准管螺纹。不同点如下：
1）螺纹牙高h不一样．NPTF内、外螺纹之间没有间隙，而NPT的内、外螺纹之间可能有过盈也可能有间隙。
2）NPT内、外螺纹均为圆锥形，而NPTF外螺纹为圆锥形，内螺纹有圆锥形和圆柱形两种。
3）NPT有右旋和左旋两种螺纹，而NPTF只有一种右旋螺纹。
2、1/2NPTF的牙数是14牙。 非常好 好东西，还是有点糊涂 好东西 好资料 学了点知识但还是没太明白 没什么区别