ISO 6149 O-Ring Size Chart (Metric Ports)
ISO 6149 metric port / fitting O-Ring size chart: port thread, CS×ID code, and ID/CS/OD in millimeters and inches.
History of ISO 6149 ORB Boss Chart Metric / ISO Chart
ISO 6149 covers O-Rings for metric tube fittings and ports (metric parallel threads with elastomeric seals). Each size ties to a port thread such as M10×1 or M18×1.5.
These are metric port seals - not SAE J1926 inch ORB boss rings. For inch ORB, use the ORB Boss chart.
Metric port / fitting sizes
| Port / thread | Code (CS×ID) | ID (mm) | CS (mm) | OD (mm) | ID (in) | CS (in) | OD (in) |
|---|---|---|---|---|---|---|---|
| M8 X 1 | 1.60X006.1 | 6.10 ±0.15 | 1.60 ±0.08 | 9.30 | 0.240 ±.006 | 0.063 ±.003 | 0.366 |
| M10 X 1 | 1.60X008.1 | 8.10 ±0.15 | 1.60 ±0.08 | 11.30 | 0.319 ±.006 | 0.063 ±.003 | 0.445 |
| M12 X 1.5 | 2.20X009.3 | 9.30 ±0.15 | 2.20 ±0.09 | 13.70 | 0.366 ±.006 | 0.087 ±.004 | 0.539 |
| M14 X 1.5 | 2.20X011.3 | 11.30 ±0.20 | 2.20 ±0.09 | 15.70 | 0.445 ±.008 | 0.087 ±.004 | 0.618 |
| M16 X 1.5 | 2.20X013.3 | 13.30 ±0.20 | 2.20 ±0.09 | 17.70 | 0.524 ±.008 | 0.087 ±.004 | 0.697 |
| M18 X 1.5 | 2.20X015.3 | 15.30 ±0.20 | 2.20 ±0.09 | 19.70 | 0.602 ±.008 | 0.087 ±.004 | 0.776 |
| M20 X 1.5 | 2.20X017.3 | 17.30 ±0.20 | 2.20 ±0.09 | 21.70 | 0.681 ±.008 | 0.087 ±.004 | 0.854 |
| M22 X 1.5 | 2.20X019.3 | 19.30 ±0.25 | 2.20 ±0.09 | 23.70 | 0.760 ±.010 | 0.087 ±.004 | 0.933 |
| M27 X 2 | 2.90X023.6 | 23.60 ±0.25 | 2.90 ±0.09 | 29.40 | 0.929 ±.010 | 0.114 ±.004 | 1.157 |
| M33 X 2 | 2.90X029.6 | 29.60 ±0.25 | 2.90 ±0.09 | 35.40 | 1.165 ±.010 | 0.114 ±.004 | 1.394 |
| M42 X 2 | 2.90X038.6 | 38.60 ±0.35 | 2.90 ±0.09 | 44.40 | 1.520 ±.014 | 0.114 ±.004 | 1.748 |
| M48 X 2 | 2.90X044.6 | 44.60 ±0.35 | 2.90 ±0.09 | 50.40 | 1.756 ±.014 | 0.114 ±.004 | 1.984 |
| M60 X 2 | 2.90X056.6 | 56.60 ±0.40 | 2.90 ±0.09 | 62.40 | 2.228 ±.016 | 0.114 ±.004 | 2.457 |
Other size charts
| Need | Chart |
|---|---|
| AS568 dash (0xx-4xx) | AS568 O-Ring Size Chart |
| Metric / ISO 3601 | Metric O-Ring Size Chart |
| JIS S/P/G/V | JIS B 2401 Size Chart |
| ORB / 900-series boss | ORB Boss Size Chart |
| Back-up rings | Backup Ring Size Chart |
| DIN 3771 | DIN 3771 Size Chart |
| Generic Metric | Generic Metric Size Chart |
| BS 4518 | BS 4518 Size Chart |
| BS 1806 | BS 1806 Size Chart |
| NF T 47-501 | NF T 47-501 Size Chart |
| SMS 1586 | SMS 1586 Size Chart |
| X-Ring | X-Ring Size Chart |
| Square Ring | Square Ring Size Chart |
| Parker 500 | Parker 500 Size Chart |
| ISO 6149 ports | ISO 6149 Size Chart |
| Search across standards | Master O-Ring Size Chart |
Related
History and explanation of ISO 6149
What ISO 6149 is
ISO 6149 standardizes metric port connections that seal with an O-Ring on a straight metric thread - Europe’s counterpart idea to inch ORB ports, with its own threads and seal sizes.
ISO 6149 vs SAE J1926 ORB
| ISO 6149 | SAE J1926 ORB | |
|---|---|---|
| Threads | Metric fine (M…) | UN/UNF inch |
| Seal size language | Metric CS×ID / port callout | AS568 900-series |
| Typical hardware | Metric manifolds, EU hydraulics | North American ORB ports |
Do not mix an ISO 6149 seal into a J1926 port (or the reverse) based on “similar looking” threads.
Using this chart
Read the port thread from the fitting or manifold, find the row, confirm ID/CS, then specify compound for the fluid.
