20513 Metric Female 24-Degree Cone O-Ring HEAVY INTERLOCK Hydraulic Hose Fittings (Swivel Nut)

Female 24-degree cone O-ring interlock hydraulic hose fittings are the female swivel-nut end of the big-bore interlock system: the port side seals through an O-ring in the 24-degree cone seat (DIN 3865 / DKOS-type joint, heavy schedule), while the hose side uses an interlock tail – the ribbed gripping zone with a locking profile that engages the matched interlock ferrule against blow-off under pressure impulses. The 20513 series covers 8 part numbers from DN20 (-12) to DN40 (-24), female metric threads M30x2 to M52x2 mapping to DIN heavy-series tube sizes from 20 to 38 mm. If your large-bore circuits see pressure spikes, vibration or impulse service, this page explains how the interlock female end locks the hose in place – and how to order it as a complete system.

Why Choose These Interlock O-Ring Cone Fittings

• Blow-off resistant interlock tail. The locking profile on the tail works with the matched interlock ferrule to hold the hose mechanically, not just by barb friction – the retention principle specified for the largest heavy circuits.
• O-ring already fitted in the cone seat. The 24-degree cone carries its heavy-series O-ring (sizes per part number), and the seal can be replaced without scrapping the fitting.
• Heavy (H.T.) thread schedule. M30x2 up to M52x2, the top end of the DIN heavy tube-size schedule (20 to 38 mm), for the systems that specify it.
• Swivel nut that turns freely. The nut rotates on the tail, so the connection tightens onto the cone stud without twisting the hose.
• OEM-ready. Laser marking, custom plating, material test reports and batch traceability, with replacement O-rings available.

Standards and traceability. Threads are ISO 724 metric threads. The sealing geometry follows the 24-degree cone with O-ring per DIN 3865 within the ISO 12151-2 hose-fitting standard – the O-ring cone configuration widely known in the trade as the DKOS-type joint, in its heavy (H.T.) schedule. (Note: the source sheet prints ISO 12151-1; that part of the standard covers O-ring face seal ends, so ISO 12151-2 is cited here as confirmed against the series drawings.) Fittings are designed to pair with wire-braided or spiral hose per the W/T construction ordered, built to EN 853 or EN 856 performance classes respectively. Dimensional inspection reports and material test certificates are available for OEM gate checks.

What the Interlock Tail Does on the Female Side

On a plain barbed tail, hose retention comes from the barbs biting into the tube and cover plus the ferrule grip. On a big-bore heavy circuit, pressure impulses act like a hammer on the hose end, and that is where the interlock design earns its name.

The 20513 tail carries a ribbed gripping zone plus a locking profile near the body. When the matched interlock ferrule is crimped over it, the ferrule and the tail profile engage mechanically, locking the hose in place rather than relying on barb friction alone. This is the same retention principle used on the 10513 male interlock series, so a large-bore assembly can carry the interlock system on both ends: the 10513 male where it connects to a female cone port, and the 20513 female where it connects over a male cone stud.

Interlock is a system, not a single part. The locking profile only works with the matched interlock ferrule and its crimp data. Mixing an interlock fitting with a standard ferrule removes the locking benefit and risks blow-off. For every 20513 part number you have three ordering options:

1. Fitting only – if you already hold the matched interlock ferrule and crimp data.
2. Fitting + matched interlock ferrule – the recommended option for hose assembly shops, so the tail and ferrule profiles always come from the same engineering data.
3. Complete hose assembly – we cut, crimp and pressure-test assemblies to your length and fitting list.

What do the W and T rows mean?

The 20513 table lists two tail constructions, marked -W and -T, shown as separate diagrams on the drawing. In interlock families of this type, the W and T rows carry the tail design matched to the hose reinforcement – braided (wire) hose for one, spiral hose for the other – but because the source sheet does not state the mapping in words, we confirm the correct construction for your hose on every order. Send your hose label (1SN/2SN or 4SP/4SH) with your inquiry and we will match the right part number.

20513 Series Technical Specifications

Materials and processing

• Body material options: high-strength carbon steel (20#/35#/45# grades, cold-formed or machined) as standard; stainless steel 304 or 316L available for corrosive or wash-down environments.
• Surface treatment: zinc plating as standard; yellow, white or black zinc, zinc-nickel and Dacromet coating available for higher salt-spray requirements.
• Heat treatment: hardness and case depth are controlled per drawing so the interlock profile, the thread and the cone seat stay fatigue-resistant under impulse loads; typical surface hardness range HRC 20-28 (confirm the exact code on your drawing or PO).
• O-ring: NBR as standard for mineral oils; FKM available for higher temperatures and aggressive fluids. O-ring sizes per part number in the table – these are the heavy-series sizes, not the light-series sizes.

Full dimension and part number table

All linear dimensions are in millimeters. E = thread, DN = hose bore, Tube O.D. = the DIN heavy-series tube size sharing this thread and cone geometry, O-ring = the seal supplied with the fitting (as printed in the catalog), A and C = lengths per the supplier drawing, S2 = swivel nut hex across flats. W and T rows carry the two tail constructions shown on the drawing; confirm the one matched to your hose when ordering.

Full dimensioned CAD drawings are available on request so your engineers can verify every length, the interlock profile, the cone seat and the O-ring groove before you commit a batch.

Working pressure: the honest answer engineers need

A crimp hose assembly fails at its weakest link, so the rating of a 20513 fitting depends on the hose you pair it with and the crimp quality. This series exists to serve the large-bore, high-pressure and impulse-duty circuits where blow-off resistance matters, and the pressure class is defined by the hose construction you order (braided or spiral) plus the interlock ferrule crimp. Send us your hose specification and the circuit details, and we will confirm the working pressure, burst margin and the matched interlock ferrule for your exact hose brand – the check is free and takes one message. For derating at elevated temperature, follow the hose manufacturer’s pressure-temperature curve and check the O-ring material limit for your fluid temperature.

Part Number Decoder and How to Order

The 20513 part number carries the specification – thread, bore, O-ring, tail construction – so purchasing can copy it straight into a PO:

20513 – 42 – 16W

• 20513 = 24-degree cone O-ring heavy-series interlock female
• 42 = thread nominal size (here M42x2, DIN heavy-series class for 30 mm tube)
• 16 = hose dash size (here DN25, 1-inch class bore)
• W = tail construction per the drawing (confirm braided or spiral against your hose)
• O-ring = O25.3×2.4 supplied with the fitting

Because one thread size can serve several hose bores, always quote both the thread size and the dash size. If you are replacing an existing fitting or building a new circuit, send us the hose label, the male cone stud and, if available, a photo of the old interlock ferrule – we will confirm the matching 20513 part number, the W or T construction, and the ferrule, the same day.

Assembly Guide: Four Steps with the Interlock Ferrule

Step 1 – Cut the hose square. Use a sharp hose cutter or cutoff saw. A square, clean cut lets the interlock ferrule grip the cover evenly. A beveled or ragged cut is the most common cause of pull-out failures.

Step 2 – Prepare the insert depth. Push the fitting tail into the hose until it bottoms firmly against the internal shoulder. The hose end must sit at the full insertion depth so the interlock profile and the ferrule line up correctly.

Step 3 – Lubricate and insert. Apply a thin film of assembly lubricant to the hose bore and the interlock tail. Push the fitting in with a steady twisting motion until it bottoms out, then wipe away excess lubricant. Keep the O-ring and the cone seat clean.

Step 4 – Crimp and verify. Crimp the matched interlock ferrule with the hose manufacturer’s crimp specification. After crimping, always measure the crimp outside diameter with a caliper and compare it with the crimp table. If it is out of tolerance, do not put the assembly into service – cut it off and re-crimp with a corrected setting.

Warnings: three mistakes that cause leaks and blow-outs

• Never use a standard ferrule on an interlock tail. The locking benefit comes from the matched interlock ferrule profile and its crimp data.
• Never mix the heavy and light schedules, and never substitute a light-series O-ring into this heavy cone seat – the O-ring sizes differ at the same nominal thread.
• Never put PTFE tape or sealant on the thread, and never force the swivel nut when the cone is not aligned – the O-ring seats cleanly only with a straight approach.

Typical Applications

The interlock O-ring cone system serves large-bore, high-pressure and impulse-duty hydraulic circuits, typically:

• Mining, tunneling and marine equipment with large-bore high-pressure circuits
• Heavy construction and material handling machinery
• Presses, injection molding and large hydraulic power units
• High-impulse circuits where hose blow-off history drove the interlock specification
• Hose assemblies where both ends use the interlock system (10513 male + 20513 female)

Wherever the circuit demands the interlock retention principle and the port takes a 24-degree cone O-ring joint in the heavy schedule, the 20513 series is the female hose end – complete with matched O-ring.

OEM Customization and Quality Traceability

For equipment builders and large maintenance programs, the 20513 series can be adapted to your exact drawing and your traceability rules.

Customization options

• Thread and geometry: special threads, modified lengths and non-standard configurations machined to your drawing or to a sample.
• Surface treatment: zinc-nickel, Dacromet or other coatings for higher salt-spray grades; we confirm the achieved test hours for the coating you choose instead of quoting a generic number.
• Laser marking: your logo, part number and batch or date code laser-marked on the nut or hex for full field traceability.
• Material: stainless steel 304/316L versions for corrosive media or wash-down duty.
• O-ring material: FKM or other elastomers to match your fluid and temperature.
• System supply: fitting + matched interlock ferrule kitted per assembly, or complete pressure-tested hose assemblies.
• Packaging and kitting: custom labels, barcodes and box quantities for line-side supply.

Quality documentation

• Batch number traceability: every order carries a batch code that links back to the production records.
• Material test reports (MTR) available for carbon steel and stainless batches.
• Dimensional inspection reports for OEM gate checks.
• Third-party inspection (BV, SGS or similar) can be arranged before shipment.
• Pressure test certificates available for complete assemblies.

Samples and MOQ. Samples for stock sizes ship fast, and we keep low MOQs for standard part numbers so distributors can test the series without tying up capital. OEM programs can move to scheduled deliveries once the drawing is approved.

Packaging and Logistics

Standard export packing: fittings are individually poly-bagged or boxed to protect interlock tails, O-rings, threads and cone seats, then packed in export cartons labeled with part number, quantity and batch code. Interlock ferrules are kitted with their fittings or packed separately per your process. Custom labeling and barcode requirements are available. Exact carton quantity, gross weight and CBM are confirmed on the packing list for every order.

FAQ

Q: What is a female 24-degree cone O-ring interlock hydraulic hose fitting? A: It is a swivel-nut female hose end with an O-ring in the 24-degree cone seat (DIN 3865 / DKOS-type joint, heavy schedule) and an interlock tail whose locking profile engages a matched interlock ferrule against hose blow-off.

Q: What does the interlock tail do? A: The ribbed gripping zone plus the locking profile engage the matched interlock ferrule mechanically, locking the hose in place under pressure impulses instead of relying on barb friction alone.

Q: What is the difference between the W and T part numbers? A: The W and T rows carry the two tail constructions shown on the drawing, typically matched to braided and spiral hose respectively. Because the source sheet does not state the mapping in words, we confirm the correct construction for your hose on every order.

Q: Is the interlock ferrule included? A: Order option 1 (fitting only), option 2 (fitting + matched interlock ferrule) or option 3 (complete pressure-tested assembly). A standard ferrule must never be used on an interlock tail.

Q: Is the O-ring included? A: Yes. Each part number carries its listed heavy-series O-ring (for example O25.3×2.4 for the M42x2 sizes). Replacement O-rings are available.

Q: What is the difference between 20513 and 20511? A: 20511 is the plain-tail heavy O-ring cone female; 20513 uses the interlock tail for blow-off resistance on large-bore, high-impulse circuits. Same cone/O-ring geometry, different retention design on the hose side.

Q: What is the difference between 20513 and 10513? A: 10513 is the male 24-degree cone interlock series and 20513 is the female swivel interlock series. Together they put the interlock system on both ends of an assembly.

Q: What is the working pressure of these fittings? A: The rating is defined by the hose construction, the matched interlock ferrule and the crimp quality. Send your hose specification and circuit details and we will confirm the working pressure for your combination.

Q: Can you make custom part numbers with my logo? A: Yes. We offer laser marking, custom plating, stainless versions, O-ring material options and special dimensions, with MTR and batch traceability for OEM programs.

Order Today: Interlock O-Ring Cone Females with Confirmed Fit

Every 20513 female 24-degree cone O-ring interlock hydraulic hose fitting in this range ships with its heavy-series O-ring, is made to controlled dimensions, inspected before packing and backed by batch traceability. Send us your hose label, thread size and a photo of the male cone stud, and you will get a confirmed part number, the correct W or T construction, the matched interlock ferrule, a delivery date and a quote within one working day. Request samples first and pull-test one assembly on your own bench – the interlock profile is the difference between a fitting that grips and a fitting that holds. We make sure the fitting, ferrule, hose and O-ring work as one leak-free, blow-off-resistant assembly.