Quick answer: 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.
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.
Last updated October 2026.
Quick answer
| Screw | Size | Where it goes |
|---|---|---|
| Wire terminal screws (2) | M3 x 4mm, Phillips | Clamp the two doorbell wires on wired models and Nest Hello |
| Wall mounting screws (2) | #6 x 1" (about 25mm), self-tapping | Hold the base plate or wall mount to the wall, with anchors in brick, stucco or drywall |
Shop the screws in this guide
Nest Doorbell 1st Gen Terminal Screws, M3 x 4mm, 10-PackView & buy →
Nest Doorbell Terminal Screw, M3 x 4mm, SingleView & buy →
Ring Doorbell Gen 1 Terminal Screws, M3 x 4mm, 10-PackView & buy →
Listed for Google Nest Doorbell 1st Gen (Nest Hello, wired). See all smart home & doorbell screws.
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): has no wire terminals unless you wire it to an existing doorbell circuit, so on most installs the only screws are the wall mounting screws. The doorbell comes off its mount with the small release tool supplied in the box rather than by removing a screw; keep that tool somewhere you will find it.
Nest Doorbell (wired) / Nest Hello: uses both the wall mounting screws and the M3 x 4mm terminal screws for the doorbell wiring connections.
How to Check a Screw Before You Order
If one terminal screw is still in the doorbell, take it out and use it as your reference. An M3 screw has a 3mm thread diameter and a standard 0.5mm thread pitch; measured with calipers across the threads it reads just under 3mm, and it will not thread into an imperial #4 or #6 hole without binding. Length is measured from under the head to the tip, not including the head.
No screw left to measure? Compare the empty hole with our Screw Size Finder, or order the M3 x 4mm pack above: every wired Nest Doorbell and Nest Hello terminal in this guide uses that one size. A small #1 Phillips screwdriver fits these heads; a larger bit strips them easily.
What If You Lost a Different Small Screw?
Some installs pick up extra hardware, such as a wedge or angle mount, a chime connector or a third-party cover with its own security screw. Those are not the same part as the terminal screws, so measure the thread (most small electronics screws are M2, M2.5 or M3) with calipers or the Screw Size Finder and 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.
