20491 90-Degree Elbow Metric Female 24-Degree Cone O-Ring LIGHT-Series Hydraulic Hose Fittings

Metric female O-ring cone elbow fittings add a 90-degree turn to a 24-degree cone O-ring connection, changing direction in the steel elbow instead of bending the hose. The 20491 light-series (L.T.) elbow carries its O-ring in the cone seat of the swivel nut – with the O-ring size printed on every part number – and connects onto 24-degree cone male studs of the light schedule, per ISO 12151-2 / DIN 3865, the O-ring cone configuration known in the trade as the DKOS-type joint. The series covers 23 part numbers from M12x1.5 (DN5, -03) to M52x2 (DN40, -24), mapping to DIN light-series tube classes from 6 to 42 mm, designed for wire-braided hose. If your machine connects hose onto light-series 24-degree O-ring cone male studs and the routing needs a compact turn, this page gives you the full reference: dimensions, O-rings, part numbers and OEM options.

Why Choose These O-Ring Cone Elbow Fittings

• O-ring already fitted in the cone seat. The 24-degree cone carries its O-ring, and the size is printed on each part number – no separate seal shopping at the bench.
• The forgiving O-ring cone joint. The O-ring does the primary sealing with metal cone backup (DIN 3865 / DKOS-type joint), tolerating surface wear that a bare metal cone would leak on.
• Turn the corner in steel, not in the hose. The 90-degree elbow keeps the hose inside its minimum bend radius at the connection – smaller envelopes and longer hose life.
• Light-series (L.T.) thread schedule. DIN light-series threads, M12x1.5 for a 6 mm tube class up to M52x2 for 42 mm.
• Swivel nut for orientation. The nut turns freely, so the elbow plane is set toward the routing before the joint is torqued – no twisted 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. Fittings are designed to pair with wire-braided hose built to EN 853 1SN/2SN or SAE 100 R1AT/R2AT performance classes. Dimensional inspection reports and material test certificates are available for OEM gate checks.

O-Ring Cone vs Multiseal vs Metal Cone Elbows

The 24-degree cone system appears in three female-seat variants in this catalog, and the elbows follow the variant of the male stud:

The O-ring version tolerates surface wear better and holds a seal under vibration and low-pressure conditions where a bare metal joint may weep. Because the three variants look similar at a glance, always confirm the male stud type before ordering – a photo of the stud and the old nut is enough for a same-day answer.

What does the O-ring column in the table mean?

Every part number lists its O-ring, for example O12.0x2.0 for the M22x1.5 sizes – the same O-rings as the 20411 straight series. Replacement O-rings are available separately. Standard O-rings are NBR for mineral oils; FKM seals are available for higher temperatures and aggressive fluids.

What does the T suffix mean?

Rows ending in T carry the nut construction shown on the 20491-T drawing, with a slightly different shoulder profile behind the swivel nut. Both constructions use the same thread, tube class, cone seat and O-ring. Order the exact part number from your drawing or the old fitting, and we will confirm the construction before dispatch.

What does the Tube O.D. column mean?

It shows the DIN light-series tube class sharing this thread and cone geometry (for example 15 mm tube takes M22x1.5), so drawings that state tube sizes can be looked up directly.

20491 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 elbow body, thread, cone seat and nut stay fatigue-resistant; 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.
• Elbow geometry: swept 90-degree bend, machined as one piece with the body.

Full dimension and part number table

All linear dimensions are in millimeters. E = thread, DN = hose bore, Tube O.D. = the DIN light-series tube class 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, H = overall elbow height per the drawing, S2 = swivel nut hex across flats. Rows ending in T use the alternate nut construction shown on the 20491-T drawing.

Full dimensioned CAD drawings are available on request so your engineers can verify every length, the elbow height, 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 20491 elbow depends on the hose you pair it with and the crimp quality. Wire-braided hydraulic hose in this size range typically operates between roughly 80 and 400 bar depending on bore size and construction (1SN or 2SN). Send us your hose specification and we will confirm the working pressure, burst margin and the recommended 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.

Which Fitting Series Do You Need: 20491 (Braided) or 20492 (Spiral)?

The part number changes with the hose construction, because the barb geometry and the crimp parameters are different. For spiral-reinforced hose (4SP/4SH style), order the 20492 series as 20492-XX-XX. Check the hose label before ordering: braided hose is marked 1SN, 2SN or R1AT, R2AT; spiral hose is marked 4SP, 4SH or similar.

Part Number Decoder and How to Order

The 20491 part number carries the whole specification – thread, tube class, bore, O-ring and construction – so purchasing can copy it straight into a PO:

20491 – 22 – 08

• 20491 = 24-degree cone O-ring light-series female elbow for braided hose
• 22 = thread nominal size (here M22x1.5, DIN light-series class for 15 mm tube)
• 08 = hose dash size (here DN12, 1/2-inch class bore)
• O-ring = O12.0x2.0 supplied with the fitting
• T suffix (where present) = alternate nut construction

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 elbow, send us a photo of the male stud, the old nut and the elbow body – we will confirm the matching part number, including the correct O-ring and construction – the same day.

Assembly Guide: Four Steps with the O-Ring Cone Elbow

Step 1 – Cut the hose square. Use a sharp hose cutter or cutoff saw. A square, clean cut lets the 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 elbow tail into the hose until it bottoms firmly against the internal shoulder. The hose end must sit at the full insertion depth, not short, or the crimp zone will be wrong.

Step 3 – Lubricate and insert. Apply a thin film of assembly lubricant to the hose bore and the barb. Push the elbow 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, verify, orient and torque. Crimp the matched ferrule with the hose manufacturer’s crimp specification and measure the crimp outside diameter against the crimp table. Then set the elbow plane to the routing direction and torque the swivel nut onto the light-series 24-degree cone stud – the nut turns freely, so the hose is never twisted to aim the elbow.

Warnings: three mistakes that cause leaks and blow-outs

• Never mix the O-ring cone, multiseal and metal cone elbows. The three 24-degree female variants match different male studs – confirm the variant before ordering.
• Never discard or swap the O-ring. Each part number carries its listed O-ring size; if a seal is damaged, order the replacement in the same size and material.
• 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.

Aplicaciones típicas

90-degree 24-degree O-ring cone light-series female elbows serve layouts that combine light-schedule O-ring cone connections with a compact right-angle turn:

• Machine tools, presses and injection molding machinery
• European-specified machines and their global service networks
• Hydraulic power units and valve stands
• Mobile equipment with compact plumbing
• Replacement service for machines with unreadable or obsolete elbow part numbers

Wherever the male stud carries a light-series 24-degree O-ring cone joint and the routing demands a 90-degree turn, the 20491 series is the elbow to specify – complete with its O-ring.

OEM Customization and Quality Traceability

For equipment builders and large maintenance programs, the 20491 series can be adapted to your exact drawing and your traceability rules.

Customization options

• Thread and geometry: special threads, modified lengths, non-standard elbow angles (for example 45 degrees) and 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 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; O-rings supplied fitted or loose per your line-side process.
• Nut construction: standard or -T variant per your drawing.
• Packaging and kitting: custom labels, barcodes, poly-bag or box quantities, and complete hose assembly kitting.

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.

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: elbows are individually poly-bagged or boxed to protect threads, O-rings, cone seats and swivel nuts, then packed in export cartons labeled with part number, quantity and batch code. Custom labeling, kitting 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 90-degree metric female 24-degree cone O-ring hydraulic hose elbow? A: It is a crimp-style 90-degree swept elbow whose port end is a female metric thread with a swivel nut carrying a 24-degree cone seat with an O-ring (ISO 12151-2 / DIN 3865, DKOS-type joint), in the light (L.T.) schedule. The O-ring is supplied with the fitting.

Q: What is the difference between the O-ring cone, multiseal and metal cone 24-degree elbows? A: The O-ring cone seals through its O-ring with metal backup (20491 light series); the multiseal version (20491C light series) uses a spherical multiseal seat; the metal cone version seals on bare metal. Match the elbow to the male stud variant.

Q: Is the O-ring included? A: Yes. Each part number carries its listed O-ring (for example O12.0x2.0 for the M22x1.5 sizes). Replacement O-rings are available.

Q: What does the Tube O.D. column mean? A: It shows the DIN light-series tube class sharing this thread and cone geometry (for example 15 mm tube takes M22x1.5), so drawings that state tube sizes can be looked up directly.

Q: What does the T suffix mean? A: Rows ending in T carry the nut construction shown on the 20491-T drawing, with a slightly different shoulder profile behind the swivel nut. Both carry the same cone seat and O-ring.

Q: Can the elbow be oriented after crimping? A: Yes – the swivel nut turns freely, so the elbow plane is set toward the routing when the nut is torqued, without twisting the hose.

Q: What is the difference between 20491 and 20492 series? A: 20491 is for wire-braided hose (1SN/2SN or R1AT/R2AT) and 20492 is for spiral hose (4SP/4SH style).

Q: What is the working pressure of these elbows? A: The assembly rating depends on the hose, the ferrule and the crimp quality. Send your hose specification 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, special elbow angles and dimensions, with MTR and batch traceability for OEM programs.

Order Today: O-Ring Cone Elbows with Confirmed Fit

Every 20491 metric female 24-degree cone O-ring hydraulic hose elbow in this range ships with its O-ring, is made to controlled dimensions, inspected before packing and backed by batch traceability. Send us a photo of the male stud, your hose type and thread size, and you will get a confirmed part number – including the correct O-ring and construction – a delivery date and a quote within one working day. Request samples first and trial-fit one on your own layout: the O-ring cone seats cleanly and the swivel nut makes the elbow as easy to aim as it is to route. We make sure the fitting, ferrule and hose work as one leak-free assembly.