小米 发表于 2012-9-14 13:54

DSH 230 screws and connections


http://decisions.iecee.org/icons/ecblank.gif DSH 230

screws and connections
28.3
60335-1(ed.2) & 60335-1(ed.3)


Standard:
IEC60335-1: 2nd, 1976
IEC60335-1: 3rd, 1991
Sub-clause: 28
Sheet n. 230
Subject: RECOGNIZING DIFFERENT TYPES OF SCREWS
Key words:
-Screws
-Space threaded
-Thread cutting
Decision n. taken at 29th meeting/1992
Question: In the 2nd edition of IEC 335-1 as well as in the 3rd edition the terms
- space-threaded screws,
- thread-cutting screws,
- screws which form the thread by a swaging action
are used.
It is more and more convenient to use different types of thread-cutting and thread-forming
screws and it is difficult to identify whether it is a cutting or forming screw. The differentiation
is however necessary because for earth connections as well as for current carrying connections
restrictions concerning the use of such screws are within the specifications.
Therefore we want to show with the enclosed pictures what is our opinion on
this matter. We would like to hear the opinions of other delegates.
Decision: Mr. Reininger then introduces document IECEE/CTL (DE-EXP) 017/92, concerning IEC 335-
1, Sub-clause 28 “Screws and Connections”, the problem being recognizing different types of
screws and the judgment to which category they belong.
After discussion the Committee agrees with the German document and it was then decided to
put it into the CTL list of current decisions.


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