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請教一下什麼是螺釘有接觸壓力跟沒有接觸壓力??
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17 Electrical connections and mechanical fixings9 d+ J. ^: M3 w X; c
17.1 DE Screw TERMINALS providing electrical contact and screw fixings which during the life of the. n* T: X: ?6 [0 p, W# M8 w
apparatus will be loosened and tightened several times shall have adequate strength.. @8 _, ?( M9 h/ J
Screws exerting contact pressure and screws with a nominal diameter less than 3 mm which form part of
7 I, Z! T& B8 Mthe above-mentioned screw fixings shall screw into a metal nut or a metal insert.- r7 M+ y7 S5 ]+ `
However, screws having a nominal diameter less than 3 mm, which do not exert contact pressure, need
( X1 L5 s h0 b: ]; k. P* _! L$ q+ Gnot be screwed into metal, provided that the screw fixing withstands the torque specified in table 20 for9 L7 h( J# r* a& ?9 X. W4 E q
screws of 3 mm diameter. |
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