Xem Studiomeasured geometry

Library › Hardware › Backup rings for AS568 O-rings (Parker 8-xxx Parbak, 8-004 to…

Parker 8-389 backup ring envelope (uncut)

Parker 8-389 backup ring envelope (uncut): ID 20.006 in (508.15 mm), OD 20.372 in (517.45 mm), thickness 0.076 in (1.93 mm); for the AS568 -389 O-ring

Exact dimensions. True size, no tolerance added. Threads are plain cylinders at the major diameter.

STEP STL free, CC BY 4.0 (credit "Xem Studio")

Dimensions

dash8-389
ID (in)20.006
OD (in) = ID + 2W20.372
radial width W (in)0.183
thickness T (in)0.076
ID (mm)508.15
OD (mm)517.45
T (mm)1.93
cross-check—
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
Set it up →

From the full sheet

Backup rings for AS568 O-rings (Parker 8-xxx Parbak, 8-004 to 8-475): ID, OD, width and thickness per dash size: every size, notes, mating features and sources. What are the ID, OD and thickness of an 8-214 (or 8-110, 8-325) backup ring for an AS568 O-ring?

Other sizes