大家可以分清是什么螺钉吗？

ljh809809

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IEC60335试验指甲

In IEC 60335-1 cl 28.3
Space-threaded (sheet metal) screws shall only be used for electrical connection if they clamp the
parts together.
Thread-cutting (self-tapping)screws shall only be used for electrical connections if they generate a full form standard machine screw thread. Such screws shall not be used if they are likely to be operated by the user or installer.
7 {- [8 |* [' j9 l. O$ EThread-cutting and space-threaded screws may be used in connections providing earthing continuity provided it is unnecessary to disturb the connection in normal use and at least two screws are used for each connection.

In IEC 60598-1 cl 7.2.1 Provision for earthing
Self-tapping screws may be used to provide earthing continuity, provided that it is not necessary to disturb the connection in normal use and that at least two screws are used for each connection.
Thread-forming screws may be used to provide earthing continuity if they comply with the requirements for screw terminals.
A thread forming screw used in a groove of a metallic material could provide earth continuity for a luminaire if all the tests required withing IEC 60598-1 regarding earthign connection were passed.
1 P) q0 w; C# s: z1 Y
( @) M  ?+ u5 y! _5 VIn IEC 60950-1 cl 3.1.8 Self-tapping and space thread screws
* `  F/ U; r1 s0 t) { Spaced thread (sheet metal) screws shall not be used for the connection of current-carrying parts, unless they clamp these parts directly in contact with each other and are provided iwth a suitable means of locking.
Self-tapping (thread-cutting or thread-forming) screws shall not be used for the electrical connection of current-carrying parts, unless they generate a full form standard maching screw thread. Moreover, such screws shall not be used if they are operated by the user or installer unless the thread is formed by a swaging action.
IEC 60950-1 cl 2.6.5.7 Screws for protective bonding
, S( f* P- V; p' WSelf-tapping (thread-cutting and thread-forming) and spaced thread (sheet metal) screws are permitted to provide protective bonding but it shall not be necessary to disturb the connection during servicing.
At  least two screws shall be used for each connection. However, it is permitted to use a single self-tapping screw provided that the thickness of the metal part at the point where the screw is threaded into it is a minimum of 0,9mm for a screw of the thread-forming type and 1,6mm for a screw of the thread-cutting type.

ljh809809

按IEC 60950-1，Self-tapping (thread-cutting or thread-forming) screws shall not ... 似乎也可以理解成thread-cutting or thread-forming是属于self-tapping类的。即切削螺纹螺钉(thread-cutting )或挤压螺纹螺钉(thread-cutting )都属于自攻螺钉(Self-tapping )。
可是，按IEC 60598-1的图，又将Self-tapping ，hread-cutting or thread-forming看成三种不同的螺钉。我的疑问在这。
8 h- D9 h. [7 g哪位有没有关于螺纹螺钉的国标？

lingyuns

Space-threaded 粗牙螺纹
% `; d; N( k6 f9 cThread Forming （TF ）自攻螺纹
Self Tapping （self tapp）自切屑螺纹

ljh809809

我的问题的实质不是这几个螺钉的翻译，相信大家都知道它们的对应中文。
1 t' C- p. J% T# P
首先，请大家看一下我在第一贴新加上的附件，可以看出 self-tapping, thread-cutting and thread-forming screws大致是什么模样。从图形可以分析，self-tapping ,thread-cutting, thread-forming 是不一样的。（以下参见第一贴）
+ z  H2 P' ~6 l' X) ^% U$ z; }/ [可是，在IEC 60335-1中节选的那句： Thread-cutting (self-tapping)screws shall only be used ...似乎可以理解成thread-cutting是属于self-tapping类的。
8 ~5 t* {4 R$ A1 h- g! r在IEC 60950-1中节选的那句：Self-tapping (thread-cutting or thread-forming) screws shall not ... 似乎也可以理解成thread-cutting or thread-forming是属于self-tapping类的。

总结一下：IEC 60598-1中的图形似乎 self-tapping, thread-forming, thread-cutting是不同的screws.  而IEC 60335-1, IEC 60950-1中，似乎 thread-forming, thread-cutting是self-tapping的一种，是从属关系。
3 m, [! w% H. J/ ?9 B; N  v9 c. w问题：这些screws到底是个什么关系？

liweiqi5

呵呵。

libingcheng

不好意思，2楼写反了
% c% H; v+ t3 [5 P. }% ~" P3 z: ~, O3楼  bingo! 正解

caballo3157

Space-threaded (sheet metal) screws ：宽螺距（金属板）螺钉
Thread-cutting (self-tapping)screws ：  自攻螺钉
thread-cutting and thread-forming：切削成型螺纹和挤压（也称滚压）成型螺纹

libingcheng

Thread-cutting (self-tapping)screws :宽螺纹螺钉Thread-cutting (self-tapping)screws 自攻丝螺钉

kobe_mai

这里我都有点糊涂..听高手分析....WAITING..