Hi Jack, We have always masked the mounting holes so you don't be CC in them. I don't think I would want the screws/washers, etc. to be clamping down on spongy coatings... :-) Scott Decker | Senior Engineer, PCB Design Services CID+ | Electronic Systems Center COLLINS AEROSPACE 3445 S. 5th Street, Suite 170, Phoenix, AZ 85040 U.S.A. Tel: 602 308 5957 FAX: 602 243 2347 [log in to unmask] www.collinsaerospace.com CONFIDENTIALITY WARNING: This message may contain proprietary and/or privileged information of Collins Aerospace Systems and its affiliated companies. If you are not the intended recipient please 1) do not disclose, copy, distribute or use this message or its contents, 2) advise the sender by return e-mail, and 3) delete all copies (including all attachments) from your computer. Your cooperation is greatly appreciated. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Jack Olson Sent: Thursday, January 10, 2019 2:36 PM To: [log in to unmask] Subject: [External] [TN] Conformal Coating and Unplated Mounting Holes Is it more common to conformal coat unplated mounting holes? or designate a clearance diameter on the assembly drawing?