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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
5 k. f- P% R' |, g) n17.1 DE Screw TERMINALS providing electrical contact and screw fixings which during the life of the
G) g1 q9 K. D, K3 M% Kapparatus will be loosened and tightened several times shall have adequate strength.) a5 ?1 p. k: q( `* s: A
Screws exerting contact pressure and screws with a nominal diameter less than 3 mm which form part of( \- o) ]6 G/ D, k7 X! J+ m* q9 }& ]
the above-mentioned screw fixings shall screw into a metal nut or a metal insert.- n h. S8 }5 O) |9 c" q$ f5 o/ l
However, screws having a nominal diameter less than 3 mm, which do not exert contact pressure, need3 n5 S G* E# Y. V3 ~3 R
not be screwed into metal, provided that the screw fixing withstands the torque specified in table 20 for
4 f) z* o O& n; n$ lscrews of 3 mm diameter. |
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