# ISO 6149 — Hydraulic and pipe connection type identification

For ISO 6149, region of origin is ISO Connections; thread type (tapered or parallel) is straight threads; seat or flare angle is flat face; seal method is The male connector has straight threads with an O-ring. The female port is also straight threads machined surface to provide a smooth, flat, accurately located surface (minimum spotface), along with a chamfer where the O-ring seats. It seals when the O-ring is compressed into the chamfer when mating the male connection; interchangeability notes is similar to the SAE J514 Straight Thread O-ring Boss (ORB), this type of connection incorporates metric threads, recorded from its source on 2026-08-13.

- **Connection type:** ISO 6149 _(verified: appears in the quote below)_
- **Governing standard:** ISO 6149 _(verified: appears in the quote below)_
- **Region of origin:** ISO Connections _(our reading, not quoted from the source)_
- **Thread type (tapered or parallel):** straight threads _(verified: appears in the quote below)_
- **Seat or flare angle:** flat face
- **Seal method:** The male connector has straight threads with an O-ring. The female port is also straight threads machined surface to provide a smooth, flat, accurately located surface (minimum spotface), along with a chamfer where the O-ring seats. It seals when the O-ring is compressed into the chamfer when mating the male connection. _(verified: appears in the quote below)_
- **Interchangeability notes:** similar to the SAE J514 Straight Thread O-ring Boss (ORB), this type of connection incorporates metric threads _(verified: appears in the quote below)_

## What the source says

> ISO 6149 Port and Stud Ends with ISO 261 Threads and O-ring Seal though it is similar to the SAE J514 Straight Thread O-ring Boss (ORB), this type of connection incorporates metric threads. The male connector has straight threads with an O-ring. The female port is also straight threads machined surface to provide a smooth, flat, accurately located surface (minimum spotface), along with a chamfer where the O-ring seats. It seals when the O-ring is compressed into the chamfer when mating the male connection. This is also considered a mechanical connection.

## Source

- https://brennaninc.com/connection-types/

Last verified: 2026-08-13. Review by: 2028-08-12.
Part of [Hydraulic and pipe connection type identification](https://referencesource.org/hydraulic-pipe-connection-types/).