Avionics rack mounting question

[JanRV6UK]

What size screws are normally used for mounting the racks ? It looks like #8 screws ... but I have a rack for a Bendix King KT74 transponder and the holes in the rack "could" fit a #6 screw unless I drill out the hole with a 19 drill... as I do not yet have the transponder ... or the mounting instructions ... I worry that #8 screw heads may interfere with the transponder when it slides in place ...

The rack I have for the COM unit (Garmin GTR 225) looks to be straight forward countersunk #8 screws ... same for the audio unit as well ... It is just the KT74 units that I am not sure about ...

 

[Walt]

#6 is standard.

 

[JanRV6UK]

Thanks Walt ! ... Would that then be with a countersunk head or a round head for the #6 screws ?

 

[az_gila]

Thanks Walt ! ... Would that then be with a countersunk head or a round head for the #6 screws ?

The King manual I checked (KY-97A) says the tray holes are oversize at 0.187 diam. and to use #6 Flat head Philips screws.

With the dimples stamped in the tray around the hole, the countersunk screws will nicely center in the holes.

 

[JanRV6UK]

Thanks Gil & Walt ...