Skip to content

Ports – ISO 11926-1 profiles

The plug and the UQDB socket have stud ends with straight thread and O-ring (OCP Table 5). The port they screw into – in the test rig adapters and fixtures – follows ISO 11926-1:1995, Ports with O-ring seal in truncated housing (OCP reference [3]). This page shows the inside profile of every port used in this project, with all dimensions and tolerances from the standard.

Where do the numbers come from?

Dimensions, tolerances and notes: ISO 11926-1:1995, Figure 1 and Table 1, in millimetres as in the standard. Inch values are derived (mm ÷ 25.4). Which ports are used: OCP UQD v2.0.0 Table 5. Drawings are our own redrawing, generated by scripts/gen-port-drawings.py.

Use ISO 11926-1 – not the inch table

The inch port table we used first gives several limits that do not meet ISO 11926-1, for example a shorter tap drill depth (L2) on four of the five ports and a smaller spotface (d2) on port -6. Machine and inspect to the values on this page. The full comparison is in section 5.

Still missing – thread limits (MD-035)

The thread is class 2B (internal) and conforms to ISO 725; tap drills per ISO 2306 (Table 1, note 1). The limits for the thread's pitch, major and minor diameter are not in our sources, so the thread is drawn schematically and not dimensioned.

1. Profile and symbols

Ø d2Ø d4Ø d5Ø d3L2L1L3L4⊥0.2A↗0.1AA= pitch ØThread d1 − nZ°
Z°R 0.1–0.2Ra 3.245° ±5°Detail at the cone edge (enlarged)

Port profile with the symbols of ISO 11926-1 Figure 1, redrawn (port 3/4-16 proportions). The thread is drawn schematically.

Symbol What it is (ISO 11926-1 Figure 1, Table 1) Limit
d1 − n Thread size and threads per inch, UNF-2B or UN-2B, per ISO 725 –
Ø d2 Spotface diameter – minimum recommended (note 2) min
Ø d3 Hole below the thread – for reference only; the connecting hole may need another size (note 3) ref.
Ø d4 Gauging diameter at the spotface min
Ø d5 Diameter of the O-ring cone at the spotface ± 0.05
L1 Depth of the cone, from the spotface + 0.4 / 0
L2 Tap drill depth – applies only when the tap drill cannot pass through the whole boss; needs a bottoming tap (note 4) min
L3 Spotface depth – maximum recommended, to leave wrench grip (note 5) max
L4 Length of full thread, from the spotface min
Z Cone angle ± 1°
A Datum: the thread's pitch diameter –
⊥ 0.2 A Spotface floor perpendicular to datum A within 0.2 –
↗ 0.1 A Circular run-out of the cone to datum A within 0.1 –
Ra 3.2 Surface roughness of the spotface floor and the cone (µm) max
R 0.4 max Radius at the corner of the spotface max
R 0.1–0.2 Radius at the top edge of the cone 0.1–0.2
45° ± 5° Lead-in from the cone to the thread ± 5°

Machined face (Table 1, note 2)

If the face of the port is on a machined surface, d2 and L3 need not apply as long as the radius R 0.1–0.2 is kept, so the O-ring is not damaged during installation.

2. All five ports – ISO 11926-1 Table 1

Code Thread d1 − n Ø d2 min Ø d3 ref. Ø d4 min Ø d5 ±0.05 L1 +0.4/0 L2 min L3 max L4 min Z ±1°
-4 7/16-20 UNF-2B 21 4.5 15 12.45 2.4 14 1.6 11.5 12°
-6 9/16-18 UNF-2B 25 7.5 18 15.7 2.5 15.5 1.6 12.7 12°
-8 3/4-16 UNF-2B 30 10 22 20.65 2.5 17.5 2.4 14.3 15°
-10 7/8-14 UNF-2B 34 12.5 26 24 2.5 20 2.4 16.7 15°
-12 1 1/16-12 UN-2B 41 16 32 29.2 3.3 23 2.4 19 15°

Millimetres, as in the standard.

3. Drawing per port

Pick a port. Each drawing is scaled to fill the width, so the five drawings are not at the same scale – compare sizes in the table above. Values in millimetres as in the standard; inch values are derived (mm ÷ 25.4). Tap or click a drawing to open it full screen. The 3D model above the drawing shows the same port; drag it to turn it. Unlike the drawings it keeps one scale, so it grows and shrinks with the port size. Its thread is schematic.

Port -4 · 7/16-20 UNF-2B

Designation: Port ISO 11926-1 - 7/16 - 20
Used for: Plug stud ORB-04 · size 02 (UQD + UQDB)

Ø d2 21 minØ d4 15 minØ d5 12.45 ±0.05Ø d3 4.5 ref.L2 14 mintap drill depthL1 2.4 +0.4/0L3 1.6 maxL4 11.5 minfull thread⊥0.2A↗0.1AA= pitch Ø7/16-20 UNF-2BZ 12° ±1°Ra 3.2 on spotface and cone · R 0.4 max at spotface cornerR 0.1–0.2 at cone edge · lead-in 45° ±5° · thread schematic
Symbol What it is mm Limit inch (derived)
Ø d2 Spotface diameter 21 min 0.827
Ø d3 Hole below the thread 4.5 reference only 0.177
Ø d4 Gauging diameter 15 min 0.591
Ø d5 Cone diameter at the spotface 12.45 ± 0.05 0.490
L1 Cone depth 2.4 + 0.4 / 0 0.094
L2 Tap drill depth 14 min 0.551
L3 Spotface depth 1.6 max 0.063
L4 Full thread length 11.5 min 0.453
Z Cone angle 12° ± 1° –
Thread d1 − n, class 2B, ISO 725 – not in our sources (MD-035) –

Port -6 · 9/16-18 UNF-2B

Designation: Port ISO 11926-1 - 9/16 - 18
Used for: Plug stud ORB-06 · size 04  |  UQDB socket stud ORB-06 · size 02

Ø d2 25 minØ d4 18 minØ d5 15.7 ±0.05Ø d3 7.5 ref.L2 15.5 mintap drill depthL1 2.5 +0.4/0L3 1.6 maxL4 12.7 minfull thread⊥0.2A↗0.1AA= pitch Ø9/16-18 UNF-2BZ 12° ±1°Ra 3.2 on spotface and cone · R 0.4 max at spotface cornerR 0.1–0.2 at cone edge · lead-in 45° ±5° · thread schematic
Symbol What it is mm Limit inch (derived)
Ø d2 Spotface diameter 25 min 0.984
Ø d3 Hole below the thread 7.5 reference only 0.295
Ø d4 Gauging diameter 18 min 0.709
Ø d5 Cone diameter at the spotface 15.7 ± 0.05 0.618
L1 Cone depth 2.5 + 0.4 / 0 0.098
L2 Tap drill depth 15.5 min 0.610
L3 Spotface depth 1.6 max 0.063
L4 Full thread length 12.7 min 0.500
Z Cone angle 12° ± 1° –
Thread d1 − n, class 2B, ISO 725 – not in our sources (MD-035) –

Port -8 · 3/4-16 UNF-2B

Designation: Port ISO 11926-1 - 3/4 - 16
Used for: Plug stud ORB-08 · size 06  |  UQDB socket stud ORB-08 · size 04

Ø d2 30 minØ d4 22 minØ d5 20.65 ±0.05Ø d3 10 ref.L2 17.5 mintap drill depthL1 2.5 +0.4/0L3 2.4 maxL4 14.3 minfull thread⊥0.2A↗0.1AA= pitch Ø3/4-16 UNF-2BZ 15° ±1°Ra 3.2 on spotface and cone · R 0.4 max at spotface cornerR 0.1–0.2 at cone edge · lead-in 45° ±5° · thread schematic
Symbol What it is mm Limit inch (derived)
Ø d2 Spotface diameter 30 min 1.181
Ø d3 Hole below the thread 10 reference only 0.394
Ø d4 Gauging diameter 22 min 0.866
Ø d5 Cone diameter at the spotface 20.65 ± 0.05 0.813
L1 Cone depth 2.5 + 0.4 / 0 0.098
L2 Tap drill depth 17.5 min 0.689
L3 Spotface depth 2.4 max 0.094
L4 Full thread length 14.3 min 0.563
Z Cone angle 15° ± 1° –
Thread d1 − n, class 2B, ISO 725 – not in our sources (MD-035) –

Port -10 · 7/8-14 UNF-2B

Designation: Port ISO 11926-1 - 7/8 - 14
Used for: Plug stud ORB-10 · size 08  |  UQDB socket stud ORB-10 · size 06

Ø d2 34 minØ d4 26 minØ d5 24 ±0.05Ø d3 12.5 ref.L2 20 mintap drill depthL1 2.5 +0.4/0L3 2.4 maxL4 16.7 minfull thread⊥0.2A↗0.1AA= pitch Ø7/8-14 UNF-2BZ 15° ±1°Ra 3.2 on spotface and cone · R 0.4 max at spotface cornerR 0.1–0.2 at cone edge · lead-in 45° ±5° · thread schematic
Symbol What it is mm Limit inch (derived)
Ø d2 Spotface diameter 34 min 1.339
Ø d3 Hole below the thread 12.5 reference only 0.492
Ø d4 Gauging diameter 26 min 1.024
Ø d5 Cone diameter at the spotface 24 ± 0.05 0.945
L1 Cone depth 2.5 + 0.4 / 0 0.098
L2 Tap drill depth 20 min 0.787
L3 Spotface depth 2.4 max 0.094
L4 Full thread length 16.7 min 0.657
Z Cone angle 15° ± 1° –
Thread d1 − n, class 2B, ISO 725 – not in our sources (MD-035) –

Port -12 · 1 1/16-12 UN-2B

Designation: Port ISO 11926-1 - 1 1/16 - 12
Used for: UQDB socket stud ORB-12 · size 08

Ø d2 41 minØ d4 32 minØ d5 29.2 ±0.05Ø d3 16 ref.L2 23 mintap drill depthL1 3.3 +0.4/0L3 2.4 maxL4 19 minfull thread⊥0.2A↗0.1AA= pitch Ø1 1/16-12 UN-2BZ 15° ±1°Ra 3.2 on spotface and cone · R 0.4 max at spotface cornerR 0.1–0.2 at cone edge · lead-in 45° ±5° · thread schematic
Symbol What it is mm Limit inch (derived)
Ø d2 Spotface diameter 41 min 1.614
Ø d3 Hole below the thread 16 reference only 0.630
Ø d4 Gauging diameter 32 min 1.260
Ø d5 Cone diameter at the spotface 29.2 ± 0.05 1.150
L1 Cone depth 3.3 + 0.4 / 0 0.130
L2 Tap drill depth 23 min 0.906
L3 Spotface depth 2.4 max 0.094
L4 Full thread length 19 min 0.748
Z Cone angle 15° ± 1° –
Thread d1 − n, class 2B, ISO 725 – not in our sources (MD-035) –

4. Which port goes where

Port Thread Plug stud (UQD + UQDB) UQDB socket stud
-4 7/16-20 UNF-2B size 02 (ORB-04) –
-6 9/16-18 UNF-2B size 04 (ORB-06) size 02 (ORB-06)
-8 3/4-16 UNF-2B size 06 (ORB-08) size 04 (ORB-08)
-10 7/8-14 UNF-2B size 08 (ORB-10) size 06 (ORB-10)
-12 1 1/16-12 UN-2B – size 08 (ORB-12)

The UQD (handmate) socket has a hosebarb, not a stud end, so it needs no port (OCP Table 5). The stud ends themselves are ISO 11926-3 (L series); suggested tightening torque is in OCP Table 5 and in 02 Parameters.

5. Comparison with the supplied inch table

The inch table (letters A–H, supplied 2026-10-16) was converted to mm (× 25.4) and checked against ISO 11926-1 Table 1. The letters map to the ISO symbols by their place in the two figures. The inch table has no value for d4 and no geometric tolerances.

Many differences are only a few hundredths of a millimetre and come from rounding between inch and mm. Some are larger and matter for machining: spotface d2 on port -6 is 0.39 mm under the ISO minimum, and tap drill depth L2 on port -10 is 0.16 mm under. In every case, follow ISO 11926-1.

-4 · 7/16-20 UNF-2B
Inch table → ISO Inch table Inch table in mm ISO 11926-1 (mm) Result
G → d2 0.828 min ≥ 21.03 ≥ 21 OK
A → d3 0.172 min 4.37 4.5 ref. reference only
F → d5 0.487 +.005/−0 12.37–12.50 12.40–12.50 outside ISO range (12.37–12.50)
C → L1 0.093 +.015/−0 2.36–2.74 2.40–2.80 outside ISO range (2.36–2.74)
D → L2 0.547 min ≥ 13.89 ≥ 14 below ISO min (13.89 < 14)
E → L3 0.062 max ≤ 1.57 ≤ 1.6 OK
B* → L4 0.454 min ≥ 11.53 ≥ 11.5 OK
H → Z 12° ±1° – 12° ±1° OK
-6 · 9/16-18 UNF-2B
Inch table → ISO Inch table Inch table in mm ISO 11926-1 (mm) Result
G → d2 0.969 min ≥ 24.61 ≥ 25 below ISO min (24.61 < 25)
A → d3 0.297 min 7.54 7.5 ref. reference only
F → d5 0.616 +.005/−0 15.65–15.77 15.65–15.75 outside ISO range (15.65–15.77)
C → L1 0.097 +.015/−0 2.46–2.84 2.50–2.90 outside ISO range (2.46–2.84)
D → L2 0.609 min ≥ 15.47 ≥ 15.5 below ISO min (15.47 < 15.5)
E → L3 0.062 max ≤ 1.57 ≤ 1.6 OK
B* → L4 0.500 min ≥ 12.70 ≥ 12.7 OK
H → Z 12° ±1° – 12° ±1° OK
-8 · 3/4-16 UNF-2B
Inch table → ISO Inch table Inch table in mm ISO 11926-1 (mm) Result
G → d2 1.188 min ≥ 30.18 ≥ 30 OK
A → d3 0.391 min 9.93 10 ref. reference only
F → d5 0.811 +.005/−0 20.60–20.73 20.60–20.70 outside ISO range (20.60–20.73)
C → L1 0.100 +.015/−0 2.54–2.92 2.50–2.90 outside ISO range (2.54–2.92)
D → L2 0.688 min ≥ 17.48 ≥ 17.5 below ISO min (17.48 < 17.5)
E → L3 0.094 max ≤ 2.39 ≤ 2.4 OK
B* → L4 0.562 min ≥ 14.27 ≥ 14.3 below ISO min (14.27 < 14.3)
H → Z 15° ±1° – 15° ±1° OK
-10 · 7/8-14 UNF-2B
Inch table → ISO Inch table Inch table in mm ISO 11926-1 (mm) Result
G → d2 1.344 min ≥ 34.14 ≥ 34 OK
A → d3 0.484 min 12.29 12.5 ref. reference only
F → d5 0.942 +.005/−0 23.93–24.05 23.95–24.05 outside ISO range (23.93–24.05)
C → L1 0.100 +.015/−0 2.54–2.92 2.50–2.90 outside ISO range (2.54–2.92)
D → L2 0.781 min ≥ 19.84 ≥ 20 below ISO min (19.84 < 20)
E → L3 0.094 max ≤ 2.39 ≤ 2.4 OK
B* → L4 0.656 min ≥ 16.66 ≥ 16.7 below ISO min (16.66 < 16.7)
H → Z 15° ±1° – 15° ±1° OK
-12 · 1 1/16-12 UN-2B
Inch table → ISO Inch table Inch table in mm ISO 11926-1 (mm) Result
G → d2 1.625 min ≥ 41.27 ≥ 41 OK
A → d3 0.609 min 15.47 16 ref. reference only
F → d5 1.148 +.005/−0 29.16–29.29 29.15–29.25 outside ISO range (29.16–29.29)
C → L1 0.130 +.015/−0 3.30–3.68 3.30–3.70 OK
D → L2 0.906 min ≥ 23.01 ≥ 23 OK
E → L3 0.094 max ≤ 2.39 ≤ 2.4 OK
B* → L4 0.750 min ≥ 19.05 ≥ 19 OK
H → Z 15° ±1° – 15° ±1° OK

ISO 11926-1 in short

  • Ports may be used up to 63 MPa (630 bar) with non-adjustable and 40 MPa (400 bar) with adjustable stud ends; the allowed pressure depends on size, material, design and use (§1).
  • For new designs in hydraulic fluid power, ISO 11926 is not to be used – ISO 6149 is (§1). The OCP UQD specification still names ISO 11926 for the UQD stud ends.
  • Ports are tested together with the stud ends per ISO 11926-2 and ISO 11926-3 (§5).
  • Designation example: Port ISO 11926-1 - 1/2 - 20 (§6).