17 mm ball joint for phone mounts (ball stud) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/phone-mount-ball-17mm/  (CC BY 4.0)
Basis: The 17 mm ball is the de facto size of car and bike phone-holder ball joints, as named in maker listings (e.g. OOKWE's universal 17 mm ball head vent adapter) and community socket sets; no maker publishes the socket
Catalog version: 2026-10-20

Sizes: see table below
- Most clip-on car phone holders, vent clips, dashboard and suction bases join with a Ø17 mm ball on the base and a split socket with a screw collar on the phone head.
- File: a ball stud with the Ø17.0 ball (the interface) on a Ø8 neck and a Ø20 × 4 foot. The neck and foot are my design, to union onto your own base (a clamp ring, a vent clip, a plate).
- The socket side (its split, the collar thread and the cup depth) is not published by any maker I found and is not drawn. A socket is sized to grip Ø17.0.
- This is not the 1 in (25.4) ball of RAM-style B-size mounts: see ram-mount-ball-sizes.

feature  mm  from
ball  Ø17.0  maker listings (OOKWE), community socket sets
neck  Ø8  my design
foot  Ø20 × 4  my design
socket, collar thread  not published  —

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- OOKWE (listing by Walmart): Car air vent mount clip adapter, universal 17 mm ball head — web — reference [verify license at link] — https://www.walmart.com/ip/945843992
- MakerWorld (community): Ball joint socket set for phone mounts (17 mm), described as the industry-standard 17 mm ball system — STL/3MF — varies per upload [verify license at link] — https://makerworld.com/en/models/3070848

Free files (CC BY 4.0, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/phone-mount-ball-17mm/index.json
API: https://xemstudio.com/api/geometry?object=phone-mount-ball-17mm