Dropped one of those tiny Google Nest Doorbell screws during installation? You're not alone — the terminal screws and mounting screws that ship with Nest Doorbells are some of the most commonly lost pieces of smart home hardware. This guide covers the exact screw sizes for every Nest Doorbell model so you can get a replacement that fits the first time.
Nest Doorbell Terminal Screw Size
The terminal screws — the two small screws that clamp your doorbell wires to the back of the unit — are M3 x 4mm machine screws on the Google Nest Doorbell (wired, 1st and 2nd gen) and Nest Hello. These are metric screws with a 3mm thread diameter and 4mm length, with a Phillips drive.
If yours went missing, our smart home & doorbell screws collection carries exact-fit M3 x 4mm replacement terminal screws for the Google Nest Doorbell in a 10-pack — enough spares that losing one never stalls an install again.
Nest Doorbell Mounting Screw Size
The wall mounting screws that secure the Nest Doorbell base plate are standard #6 self-tapping screws, roughly 25mm (1") long, paired with wall anchors for masonry or drywall. Google includes two in the box. Any #6 x 1" pan head screw works as a replacement for wood or anchor mounting; use the supplied anchors (or standard #6-8 anchors) in brick, stucco, or drywall.
Battery vs. Wired Models
Nest Doorbell (battery): uses the mounting plate screws plus an anti-theft security screw at the base — a small Torx-drive screw that releases the doorbell from its plate.
Nest Doorbell (wired) / Nest Hello: uses both the wall mounting screws and the M3 x 4mm terminal screws for the doorbell wiring connections.
What If You Lost the Security Screw?
The small release/security screw on battery models is proprietary-ish but replaceable — measure the thread (typically M2.5 or M3) with calipers or compare against our Screw Size Finder to identify it, then match it in our micro screw collections.
Frequently Asked Questions
What size are Google Nest Doorbell terminal screws? M3 x 4mm Phillips machine screws. Both wire terminals use the same size.
Can I use any screw to mount my Nest Doorbell? For the wall plate, any #6 x 1" screw with an appropriate anchor works. For the wire terminals, you need the exact M3 x 4mm size — longer screws can damage the housing, and imperial screws will cross-thread.
Does Google sell replacement screws? Google support can sometimes send mounting hardware, but terminal screws are generally not sold separately by Google — aftermarket M3 x 4mm replacements are the fast option.
What about Ring doorbells? Ring uses different hardware — see our Ring Doorbell mounting screws guide.
Get Exact-Fit Nest Doorbell Screws
Skip the hardware-store guessing game: our Nest & Ring doorbell screws collection lists thread size and length on every product. Orders over $10 ship free from South Carolina, USA.
