The code is the tube
15L takes a 15 mm tube, 16S a 16 mm tube. The number is the tube outside diameter in millimetres; the letter is the series.
Reference tool — not a selection
Name a cutting ring fitting before it goes in an RFQ.
24° cone fitting
Code, thread, tube or spanner.
Enter what you have. Where more than one size fits, pick one to see it in section; the RFQ line follows the size picked. Below the examples, the series code of an offered fitting can be checked against it: tube, series and nut thread.
A bare number is
Examples:
Replacement check
On the series codes alone: the body (straight, elbow, tee), the material and the seal (cutting ring or O-ring) decide.
All 130 engineering tools
Hydraulic and instrument piping on board is joined with 24° cone fittings to ISO 8434-1 (DIN 2353): a body with a 24° cone, a cutting ring that bites into the tube, and a nut. They come in a light series (L) and a heavy series (S), and the size code is the tube outside diameter with the series letter: 15L, 16S. Enter the code, the nut thread, the tube diameter or the spanner size, and the identifier lists the sizes that fit, draws the joint in section and writes the RFQ line.
Six nut threads belong to two series — M30x2 is both 22L and 20S — so a thread alone rarely settles it; the tube diameter does. The extra light series (LL) is not read here.
How the sizes are named
Tube first, then the series.
L light, S heavy
The heavy series has a larger nut thread on the same tube and goes on higher pressures: a 12 mm tube takes M18x1.5 in L and M20x1.5 in S.
A thread can be shared
Six nut threads, from M14x1.5 to M52x2, each serve one L and one S size: M30x2 is 22L or 20S. Measure the tube to tell them apart.
| Tube, mm | L | Thread | Spanner | S | Thread | Spanner |
|---|---|---|---|---|---|---|
| 6 | 6L | M12x1.5 | 14 | 6S | M14x1.5 | 17 |
| 8 | 8L | M14x1.5 | 17 | 8S | M16x1.5 | 19 |
| 10 | 10L | M16x1.5 | 19 | 10S | M18x1.5 | 22 |
| 12 | 12L | M18x1.5 | 22 or 24 | 12S | M20x1.5 | 24 or 27 |
| 15 | 15L | M22x1.5 | 27 | — | — | — |
| 16 | — | — | — | 16S | M24x1.5 | 30 |
| 18 | 18L | M26x1.5 | 32 | — | — | — |
| 20 | — | — | — | 20S | M30x2 | 36 |
| 22 | 22L | M30x2 | 36 | — | — | — |
| 25 | — | — | — | 25S | M36x2 | 46 |
| 28 | 28L | M36x2 | 41 | — | — | — |
| 30 | — | — | — | 30S | M42x2 | — |
| 35 | 35L | M45x2 | 50 | — | — | — |
| 38 | — | — | — | 38S | M52x2 | 60 |
| 42 | 42L | M52x2 | 60 | — | — | — |
Spanner sizes agree in both sources for sixteen sizes; for 12L they give 22 and 24 mm and for 12S 24 and 27 mm, so both figures are shown; 30S is given by one source only, so its cell is left open. Both makers also list a 14S size on M22x1.5, which is not in the DIN 2353 size list; it is left out here, as on the thread identifier. Pressure ratings differ from maker to maker and by size, so they are not given here.
Sources
Tube diameters and nut threads: Hydraulink, metric 24° cone light (MLN) and heavy (MSN) tube nut sheets, "ISO 8434-1, DIN 2353", and Hydraspecma, 24° cone face inserts of the light series (4722) and the heavy series (RO): all pairs agree. Spanner sizes: the same Hydraulink sheets and Hydraspecma item pages. Series and the 24° cone: the German Wikipedia article "Schneidringverschraubung" and Brennan Industries on DIN fittings. The DIN 2353 size list: the table reproduced by globalfastener.
Before you send the fitting
Questions about cutting ring fittings in an RFQ
What does 15L mean on a fitting?
A 24° cone fitting of the light series for a tube of 15 mm outside diameter; its nut thread is M22x1.5. The heavy series has no 15 mm size; its neighbours are 12S on M20x1.5 and 16S on M24x1.5.
How do I tell L from S?
Measure the tube outside diameter and the nut thread. For the same tube the S nut has a larger thread: a 12 mm tube takes M18x1.5 in the light series and M20x1.5 in the heavy series. Where only the thread is known, the tube decides.
Can I go by the spanner size?
As a cross-check. A 36 mm spanner fits both 22L and 20S, and for some sizes makers use different spanners, so name the thread and the tube in the request.
What should the request include?
The size code, or the tube diameter and the nut thread; the part (straight, elbow, tee, bulkhead, nut or ring); steel or stainless; the working pressure; and a photograph. If the end seals with an O-ring in the cone, say so.
Size found?
Send the line with the photographs.
An identified size is a cross-check, not proof. Attach photographs of the fitting and the tube, and Vessel Core checks them before an offer goes back.
Buyer tools
