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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 fixings' j+ O( c6 x, P, [: ~5 G; S, i
17.1 DE Screw TERMINALS providing electrical contact and screw fixings which during the life of the: z R6 Q) G9 g& x( v, |& q& [) C
apparatus will be loosened and tightened several times shall have adequate strength.
, x1 ]+ y1 j' H- zScrews exerting contact pressure and screws with a nominal diameter less than 3 mm which form part of* j0 C! w+ B- P2 T d* T0 k! E- W
the above-mentioned screw fixings shall screw into a metal nut or a metal insert.
" f/ h4 z2 [7 ]" f# Z7 WHowever, screws having a nominal diameter less than 3 mm, which do not exert contact pressure, need
{0 P {8 a& h4 Mnot be screwed into metal, provided that the screw fixing withstands the torque specified in table 20 for* \( g4 ~# N z1 j: N$ x
screws of 3 mm diameter. |
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