20491-TRW 90 Degree Metric Female 24 Degree Cone O-Ring Fitting

Our 90 degree metric female 24 degree cone O-ring fitting, series 20491-TRW, is a one-piece crimp-on elbow that connects braided hydraulic hose to metric female ports at a right angle. The 24 degree cone seat carries a pre-installed O-ring, so the seal is made the moment the swivel nut is tightened. The range covers M12x1.5 to M52x2 threads, dash size -03 to -24, hose bore DN5 to DN40. Every elbow is formed in one piece, without welding, and 100% dimensionally inspected before shipment.

Compliance and standards:

• DIN 3865 (metric 24 degree cone connector with O-ring, Form A)
• ISO 8434-1 (24 degree cone connector geometry)
• DIN 2353 light series (L.T.) dimensional standard
• ISO 12151 series (hose fittings with 24 degree cone connectors)
• SAE J516 (general hydraulic hose fitting design reference)

Why buyers choose this elbow:

• One-piece 90 degree elbow. Formed from a single forging or cold-headed blank. No weld at the bend, no weak point under impulse pressure.
• The standard right-angle connection. Pumps, valve blocks and cylinders use 90 degree outlets more than any other angle. This elbow covers them with one part.
• O-ring included with every fitting. The O-ring sits in the 24 degree cone seat and provides the seal. No tape, no paste, no guesswork at assembly.
• Small sizes included. The range starts at M12x1.5, dash -03, for DN5 hose – a size often missing from competitor elbow programs.

90 Degree Metric Female 24 Degree Cone O-Ring Fitting Technical Specifications

The table below lists all 23 sizes of the 20491-TRW 90 degree metric female 24 degree cone O-ring fitting. Dimensions are in millimeters. Each fitting ships with the O-ring size listed, matched to the cone seat. Dim. A is the horizontal distance from the nut axis to the hose-end shoulder, Dim. H is the height from the nut face to the hose axis, Dim. C is the cone zone length, and S2 is the wrench size across flats.

Notes: The -RW suffix denotes the braided-hose version; for spiral-wound hose, use series 20492-XX-XXTRW. The swivel nut is free to rotate for easy alignment before final tightening.

Why a One-Piece 90 Degree Elbow

A 90 degree outlet is the most common port direction in hydraulic systems. Pumps, valve manifolds and cylinder heads all route hoses at right angles. A straight fitting plus a separate 90 degree adapter adds two potential leak points and extra length. This 90 degree metric female 24 degree cone O-ring fitting replaces that stack with a single component.

The elbow body is formed in one piece by hot forging or cold heading, then machined to tolerance. There is no welded seam at the bend. Our impulse testing found that a one-piece elbow survives pressure cycling significantly longer than a welded two-piece elbow of the same size. The compact 90 degree geometry also keeps the hose close to the machine frame, which reduces cover wear and protects the hose from snagging.

How the O-Ring Seal Works

The O-ring sits in a groove inside the 24 degree cone seat of the swivel nut. When the mating male 24 degree cone stud is tightened, it compresses the O-ring against the cone wall. The O-ring, not the metal cone, carries the seal.

This gives three practical advantages for maintenance teams. First, the seal is forgiving of minor surface scratches on the mating cone. Second, the swivel nut can be re-tightened several times without seal degradation. Third, there is no need for thread sealant, tape or paste.

Insert Depth and Crimp O.D. – The Two Numbers Engineers Ask For

Insert depth is the length of the barbed tail that enters the hose bore. Crimp O.D. is the outside diameter of the ferrule after crimping. Together they decide whether the assembly holds pressure or leaks at the crimp zone.

HENGHUA publishes the matched insert depth and crimp O.D. for every hose construction we supply, including SAE 100 R1AT, R2AT and EN 853 1SN / 2SN. Request our crimp data sheet with your hose model and we will return the exact crimp O.D. and die selection within one working day. Our production testing found that a verified crimp O.D. within the published tolerance (typically +/- 0.2 mm) gives a burst safety margin of 4:1 or higher on the complete assembly.

Material and Heat Treatment

• Carbon steel (standard): high-strength cold-headed or hot-forged carbon steel (20# / 35# / 45# grades). The tail and cone seat are case-hardened with a carburizing and quenching process for fatigue resistance. Reference hardness range is HRC 20-28 on the core with a hardened case.
• Surface finish: white zinc or color (yellow) zinc plating with passivation. Optional zinc-nickel and Dacromet coatings are available for higher salt spray requirements.
• Stainless steel (option): 304, 316 or 316L stainless steel for corrosive media and washdown environments.
• O-ring elastomer: standard NBR (nitrile). FKM, EPDM and other elastomers are available on request for special fluids and temperatures.

Pressure and Temperature Ratings

The connection rating follows the DIN 2353 light series table below. These are reference values (§) for the fitting connection itself. The final working pressure of a hose assembly is set by the hose construction and the approved crimping specification.

§Reference values per DIN 2353 light series. Confirm the assembly rating with the HENGHUA crimp data sheet matched to your hose.

Temperature range: -40°C to +100°C with the standard NBR O-ring. At elevated temperature, apply the standard SAE J517 style derating to the assembly working pressure. The O-ring operating range can be extended with FKM material for high-temperature circuits.

Pressure testing: HENGHUA can supply assemblies proof-tested up to 100% of the rated working pressure, with test certificates on request.

How to Select the Right 90 Degree Metric Female 24 Degree Cone O-Ring Fitting

Selection is a four-step process. First, confirm the port needs a right angle. Second, match the hose bore to the dash size. Third, match the thread to your port. Fourth, confirm the hose construction version (-RW for braided, 20492 series for spiral).

Part Number Structure

Read any HENGHUA part number in three segments. Example: 20491-22-08RW.

Select by Hose Series

The 20491-TRW elbow is designed for braided hydraulic hose. Recommended matching constructions:

• SAE 100 R1AT (one wire braid) – for -03 to -24 sizes
• SAE 100 R2AT (two wire braid) – for -03 to -24 sizes
• EN 853 1SN and 2SN (equivalent European constructions)
• DIN EN 857 1SC and 2SC (compact constructions, confirm insert depth)

Select by Thread Size

The swivel nut carries a metric female thread that accepts a male 24 degree cone stud. The O-ring in the cone seat does the sealing, so the mating stud needs no additional sealing element:

• Small sizes: M12x1.5, M14x1.5, M16x1.5, M18x1.5 (dash -03 to -06)
• Medium sizes: M22x1.5, M26x1.5, M27x1.5, M30x2 (dash -05 to -12)
• Large sizes: M36x2, M45x2, M52x2 (dash -12 to -24)

The swivel nut rotates freely before tightening, which lets you align the 90 degree outlet in any direction around the port axis.

90 Degree vs 45 Degree vs Straight – Which One Do You Need

Use a straight fitting when the hose leaves the port in line with the port axis. Use a 90 degree elbow when the hose must turn immediately, such as at a pump port or valve manifold edge. Use a 45 degree elbow when the hose needs a shallow angle change. When in doubt, send us a sketch of your routing and our engineers will confirm the correct angle and size within one working day.

Cross Reference

This series replaces equivalent DIN 3865 / DIN 2353 light series 90 degree metric female fittings with O-ring available in the market. If you hold an OEM part number or a competitor catalog number, send it to our sales team. We confirm the direct replacement within 24 hours, including thread, dash size, hex, insert depth and O-ring size checks.

Packaging and Logistics

Assembly Guide: Four Steps to a Safe Hose Assembly

Follow this process for every crimped assembly. It applies to every 90 degree metric female 24 degree cone O-ring fitting size from dash -03 to -24. Skipping one step is the most common cause of early fitting failure.

Step 1 – Cut the hose square. Use a sharp hose cutter. A square cut face lets the fitting seat evenly inside the hose. A beveled or ragged cut leaves voids that become leak paths.

Step 2 – Mark the insert depth. Measure the insert depth from the HENGHUA crimp data sheet. Mark a line on the hose cover at that distance. The mark must remain visible after insertion.

Step 3 – Lubricate and insert. Apply a thin layer of compatible assembly lubricant to the hose bore and the barbed tail. Push the fitting in with a twisting motion until the depth mark aligns with the tail end. Stop at the mark. Do not force past it.

Step 4 – Crimp and verify. Select the correct die set for your hose and fitting size. Crimp in one continuous stroke. After crimping, measure the crimp O.D. with a digital caliper and compare it with the tolerance on the crimp data sheet. Record the value on your quality log. Then align the swivel nut and tighten it to the torque value on the data sheet.

Safety Warnings – Read Before Crimping

• Never mix brands. Hoses and fittings from different manufacturers may share the same dimensions but use different crimp parameters. Always use a matched hose, fitting and crimp data sheet.
• Never seal the 24 degree cone with tape. The O-ring in the cone seat provides the seal. Thread sealant tape or paste on the cone face damages the O-ring and destroys the seal.
• Check the O-ring before assembly. A cut, pinched or hardened O-ring must be replaced. The O-ring is the sealing element; never assemble without it.
• Align the swivel nut before final tightening. Rotate the 90 degree outlet to its final direction, then tighten. Do not use the hose to twist the nut into position after tightening.
• Tighten to spec. Use the hex S2 and tighten to the torque value on the data sheet. Over-tightening distorts the cone seat. Under-tightening causes vibration loosening.
• Never reuse a crimped fitting. Once crimped, the ferrule zone is work-hardened. A re-crimp cannot restore the original grip.

OEM Customization and Quality Traceability

HENGHUA supplies not only standard sizes but also fully customized 90 degree metric female 24 degree cone O-ring fitting solutions for OEM programs.

Customization Services

• Angle and thread customization. Special bend angles, non-standard thread lengths, and custom tail lengths for your hose construction.
• O-ring elastomer selection. NBR, FKM, EPDM and other elastomers matched to your fluid and temperature range.
• Surface treatment customization. White zinc, color zinc, zinc-nickel and Dacromet coatings, matched to your salt spray requirement from 72 hours up to 720+ hours.
• Laser marking. Your logo, part number and batch code laser-marked on the hex for full traceability.
• Packaging customization. Private-label boxes, barcode labels and mixed-size kits per your BOM.

Quality Traceability

Every HENGHUA batch carries a traceable batch number. The traceability chain covers incoming material certificates, heat treatment records, dimensional inspection reports, O-ring material certificates and final packing lists. Material test reports (MTR) and third-party inspection (BV, SGS or equivalent) can be arranged before shipment. Request our sample batch and audit our quality documentation – we are confident in what it shows.

Frequently Asked Questions

What is a 90 degree metric female 24 degree cone O-ring fitting?

It is a one-piece elbow fitting whose swivel nut carries a metric female thread with a 24 degree cone seat and a pre-installed O-ring. The 90 degree outlet redirects the hose at a right angle to the port axis. The geometry follows DIN 3865 and ISO 8434-1.

Why choose a 90 degree elbow instead of a straight fitting?

A 90 degree elbow turns the hose immediately at the port, which is the standard routing at pumps, valve manifolds and cylinder heads. It removes the need for a separate adapter and keeps the hose close to the machine frame.

Is the O-ring included?

Yes. Every 20491-TRW fitting ships with the matching O-ring pre-installed in the cone seat. Spare O-rings can be ordered by the size code listed in the specification table.

Which hose works with the 20491-TRW fitting?

The 20491-TRW version is designed for braided hydraulic hose such as SAE 100 R1AT, R2AT and EN 853 1SN / 2SN. For spiral-wound hose, use the 20492 series.

What is the difference between light series and heavy series?

Light series (L.T.) fittings have smaller hex and thread dimensions for the same bore and are used for lower pressure systems. Heavy series (S.T.) fittings use larger dimensions for higher pressure service. This page covers the light series per DIN 2353.

Do you supply small sizes below DN6?

Yes. The range starts at dash -03 (DN5, M12x1.5), which covers compact hydraulic circuits often used in agricultural and material handling equipment.

What is the minimum order quantity?

Stock sizes start from 100 pcs. Customized versions start from 500 pcs per size. OEM annual contracts can be discussed directly with our factory team.

Get a Quote for Your 90 Degree Metric Female 24 Degree Cone O-Ring Fitting

Tell us your hose model, thread size, bend angle and annual volume. We reply with a formal quotation, the matching crimp data sheet and our lead time within one working day. For urgent projects, our engineers support you online with crimp parameter and routing verification.