JIC Fittings Guide › JIC vs Metric (DIN 24°)
JIC vs Metric DIN 24° Cone Fittings
European and many Asian machines use metric 24° cone fittings (often called DIN 2353 or DIN fittings, now standardized as ISO 8434-1). They are sized by metric tube OD and have metric threads, so nothing on them mates directly with JIC. This page explains the metric system and how to adapt between the two. For JIC sizes see the main JIC fittings guide.
Need JIC-to-metric adapters? Get quotes from qualified distributors.
How 24° Cone Fittings Work
A 24° cone fitting has a male body with a 24° internal cone. A cutting ring (bite ring) or a welded/O-ring cone on the tube is pressed into that cone by the nut. Hose ends commonly use a 24° cone with an O-ring (often labeled DKO), which seals more reliably than a plain metal cone. JIC instead uses an external 37° flare cone with metal-to-metal sealing.
L and S Series
Metric 24° fittings come in a light (L) series and a heavy (S) series. For the same tube OD the S series uses a larger thread and is intended for higher pressure. The series letter must match.
| Tube OD | L-series thread | S-series thread |
|---|---|---|
| 6 mm | M12×1.5 | M14×1.5 |
| 8 mm | M14×1.5 | M16×1.5 |
| 10 mm | M16×1.5 | M18×1.5 |
| 12 mm | M18×1.5 | M20×1.5 |
| 15 mm | M22×1.5 | — |
| 16 mm | — | M24×1.5 |
| 18 mm | M26×1.5 | — |
| 20 mm | — | M30×2 |
| 22 mm | M30×2 | — |
| 25 mm | — | M36×2 |
| 28 mm | M36×2 | — |
| 30 mm | — | M42×2 |
| 35 mm | M45×2 | — |
| 38 mm | — | M52×2 |
| 42 mm | M52×2 | — |
Thread sizes per ISO 8434-1 (formerly DIN 2353); confirm against your supplier's catalog.
How to Tell Metric from JIC
- Check pitch with a metric gauge. Metric 24° threads use 1.5 mm or 2 mm pitch; a metric gauge fits cleanly and an inch gauge will not.
- Look at the cone. A metric male body has an internal 24° cone; a JIC male has an external 37° cone.
- Measure tube OD. Metric tube is round millimeters (6, 8, 10, 12…); JIC tube is fractional inches.
Adapting Between JIC and Metric
- JIC male × metric 24° male (L or S) adapters connect a JIC hose end to a metric system.
- Metric female swivel (DKOL/DKOS) hose ends can be paired with a JIC adapter at the machine.
- Close sizes are not equivalents: 12 mm (0.472") is not 1/2" (0.500") tube. Never force metric tube into inch fittings.
When ordering, give the series and tube OD for the metric end (e.g. "12L", M18×1.5) and the dash size for the JIC end. Also see JIC vs BSPP.
FAQ
Are DIN fittings the same as JIC?
No. DIN/ISO 8434-1 fittings use a 24° internal cone and metric threads; JIC uses a 37° external flare and inch UNF/UN threads.
What is the difference between L and S series?
For the same tube OD, S (heavy) series uses a larger thread and is intended for higher pressure than L (light) series. They do not interchange.
What does DKOL or DKOS mean?
These common catalog codes describe a 24° cone female swivel hose end with an O-ring, for L or S series respectively.
Can 12 mm tube be used in a -8 JIC fitting?
No. 12 mm is 0.472" and -8 JIC is for 1/2" (0.500") tube. Use matching tube and fittings or an adapter.
What standard covers 24° cone fittings?
ISO 8434-1, which replaced the older DIN 2353 designation.
Related guides
- JIC Fittings Guide (main)
- JIC vs NPT
- JIC vs ORFS
- JIC vs AN
- How to Identify a JIC Fitting
- JIC Thread Size Chart
- -4 JIC Fittings
- -6 JIC Fittings
- -8 JIC Fittings
- -10 JIC Fittings
- -12 JIC Fittings
- -16 JIC Fittings
- JIC vs SAE 45° Flare
- JIC vs BSPP
- JIC Torque Specs
- JIC Fitting Types
- JIC Materials & Pressure Ratings
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