DT:

        Can't help you on the torque, but you mentioned "pad/pth".
        Many designers would agree that screws should not be used in plated
thru-holes.

Joe Hurst

> -----Original Message-----
> From: Darrel Therriault [SMTP:[log in to unmask]]
> Sent: Tuesday, June 30, 1998 8:02 PM
> To:   [log in to unmask]
> Subject:      [TN] Torque on FR-4
>
> Technet,
>
> We have a backplane mounted to a chassis that has many #10 screws holding
> it in place.  Standard torque specs I use don't indicate what torque is
> appropriate for FR-4, and I am fairly certain it would not be the same as
> for a metal/metal connection.
>
> Question:
>
> Does anyone have a spec or formula for fastening FR-4 to steel/aluminum
> chassis using steel #10 screws (SEMS)??  (Or any size for that matter!!)
>
> I am speculating that FR-4 with pad/pth for screws would compress more
> then
> metal/metal
> and am concerned with some damage/fracture to the FR-4 if not torqued
> correctly.
>
> Any assistance or information appreciated...
>
> Regards...........DT
>
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