Pick the profile, or “Not known”, and enter the body size or a marking (ISO 7241 A 1/2, flat face 3/4, DN 12.5, -8). Without a size, enter the measured nose diameter of the nipple. The port thread goes into the RFQ line as written. Below, an offered half can be checked: the profile, the body size and the port thread.
On the designation alone: the material, the seals and the pressure rating are checked separately.
Push-to-connect hydraulic couplings join hoses on deck cranes, hatch covers, winches, steering gear and portable hydraulic tools. Pick the profile if you know it (ISO 7241 series A, series B or ISO 16028 flat face) and enter the body size, or measure the nose of the nipple: the tool gives the profile and the body size, the ISO size number and the nose diameter where the sources agree, draws the nipple, checks an offered half and writes an RFQ line with the port thread.
Lengths, hex sizes and the locking groove are not given: they are not the same from maker to maker. Rated pressures and flows are not given either: they are specific to each product.
ISO 7241 gives two poppet series, A and B, with different nipples: a series A nipple does not lock into a series B coupler. ISO 16028 is the flat face type, whose flat valve faces meet when the halves connect. Series A is used mainly in Europe, series B mainly in North America.
The body size (1/4", 3/8", 1/2", 3/4", 1") follows the hose the coupling serves, and ISO gives it a size number (6.3, 10, 12.5, 19, 25). A dash size counts sixteenths of an inch: -8 is 1/2".
The interchange is set by the nipple, so the nipple is what to measure: the nose diameter, just behind the front face, tells the profiles and the sizes apart. A port thread does not: the same half is made with several.
| Body size | ISO size number | ISO 7241 A, D | ISO 7241 B, D | ISO 16028, D |
|---|---|---|---|---|
| 1/8" | not given | — | 10.8 | — |
| 1/4" | 6.3 | 11.7–11.8 | 14.1–14.2 | 16.1–16.2 |
| 3/8" | 10 | differ | 19.0 | 19.7–19.8 |
| 1/2" | 12.5 | differ | 23.5–23.6 | 24.5 |
| 5/8" | not given | — | — | 27.0 |
| 3/4" | 19 | 29.0 | 31.5 | 29.9–30.0 |
| 1" | 25 | 34.3 | differ | 36.0 |
| 1-1/4" | 31.5 | 44.9 | — | — |
| 1-1/2" | not given | 55.0 | 44.5 | — |
| 2" | not given | 65.0 | 63.25 | — |
All dimensions in millimetres. A figure is given only where at least two independent sources state it and no consulted source states another value, each figure read to the precision it is printed with; where the sources print two adjacent values, both are shown (16.1–16.2). “Differ”: one consulted chart prints another value (ISO 7241 A 3/8": 17.0 against 17.2; 1/2": 20.3 against 20.5; ISO 7241 B 1": 37.6 against 37.8). “—”: that profile is not confirmed in this size by two sources. The ISO size number is left out for 1/8", 5/8", 1-1/2" and 2": the sources differ or only one gives it. Flat face couplings above 1" have no ISO 16028 size number and are left out, as are all lengths, hex sizes, locking groove diameters and pressure ratings.
Agricultural tractor couplings to ISO 5675 and screw-to-connect couplings come under separate standards and are not covered here. Some catalogues print a rounded bore as “DN” in place of the ISO size number; the tool reads such a DN as the body size and says so.
Nose diameters and ISO size numbers: a coupling maker’s product pages for male halves in its ISO 7241-A, ISO 7241-B and ISO 16028 ranges, the AKJia Hydraulic identification tables for ISO A, ISO B and ISO 16028, the Stucchi FIRG flat face data sheet, and the Summit Hydraulics and Tractor Relief Tool size charts. Size ranges: the Hydraquip, Intertraco, Midland Industries and CEJN catalogues. The two series and where they are used: the ISO 7241-1 abstract.
Look at the nipple: a flat face nipple ends in a flat face with its valve flush to it, while series A and series B nipples show a poppet in the bore. Series A and series B look alike, and the nose diameter tells them apart: at the same body size the series B nose is the larger one (at 3/4": 31.5 against 29.0 mm).
Close a caliper across the nose of the male half, the first diameter behind its front face, not across the locking groove or the hex. Read it to 0.1 mm; a worn nose reads a little under its size. The body size marked on a coupling (1/2", 3/4") is a name, not a measurement.
A figure is given only when two independent sources state it and none of the consulted sources states another value. For ISO 7241 A 3/8" and 1/2" and ISO 7241 B 1" one consulted chart prints a figure about 0.2 mm off the others, so those cells are left out; the tool still places a measurement near them and says so.
No. The interchange is set by the nipple, and the same coupling half is made with BSPP, NPT, metric or SAE port threads. The port thread decides what the half screws onto, so give it in the request as it is marked or measured.
The profile (ISO 7241 A, ISO 7241 B or ISO 16028), the body size, the measured nose diameter, the port thread, which half is needed (nipple or coupler), the seal material if it is known, the quantity, and a photograph of both halves.
The line from this tool is a cross-check of the profile and the size, not a coupling selection. Attach the photograph and your measurements, and Vessel Core checks them before an offer goes back.
