20791 90-Degree Elbow GB Metric Female 74-Degree Cone Seat Hydraulic Hose Fittings

Metric female 74-degree cone seat elbow fittings are the 90-degree swivel-nut version of the GB 74-degree cone family: the nut carries a 74-degree internal cone seat (37 degrees per side) that receives a male stud with a matching 74-degree external cone, sealing metal-to-metal without seals or tape, while the elbow turns the hose through 90 degrees in the steel. The 20791 series covers 18 part numbers from DN6 (-04) to DN40 (-24), female metric threads M12x1.5 to M52x2, designed for wire-braided hose. If you connect hose ends onto 74-degree external-cone male studs on Chinese-specified agricultural and construction machinery – and the routing needs a compact right-angle turn – this page is your reference for dimensions, thread-pitch and construction variants, part numbers and OEM options.

Why Choose These 74-Degree Cone Seat Elbow Fittings

• 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.
• The GB-standard cone geometry. 74-degree internal cone seat (37 degrees per side), the national-standard cone family used on Chinese agricultural and construction machinery ports – the female counterpart of the 10711 male series in this catalog.
• Metal-to-metal cone seal. No O-ring, no bonded seal, no thread tape – a clean machined cone joint for hydraulic oils.
• 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.

Standards and traceability. Threads are ISO 724 metric threads. The sealing cone follows the GB-series 74-degree cone geometry – catalog reference as printed on the series sheet (REF GB/T 9065.1 on the female series, REF GB/T 5628 on the male 10711 series; both labels under factory confirmation, see the notes section). The 74-degree included angle is the metric-thread cousin of the 37-degree flare family. 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.

Which Male Stud Does This Elbow Connect To?

A 74-degree cone seat elbow receives a male stud with a 74-degree external cone – no O-ring, no bonded seal, no tape. The joint is metal-to-metal: the two machined cones mate and the threads hold the preload.

Three checks before ordering:

1. Cone angle. The port stud must carry a 74-degree external cone (37 degrees per side). A 60-degree or 24-degree cone will not seal against a 74-degree seat.
2. Thread system and pitch. Metric thread and pitch must match, for example M22x1.5. The same cone angle with inch threads (JIC 74-degree flare) is a different system.
3. Construction variant. Standard rows and the C/W rows on the larger and fine-pitch sizes follow the drawing – order the exact part number.

In the catalog structure, the matching male hose end is the 10711 series (74-degree external cone male), and machine-side male studs with the same cone geometry connect directly to this 20791 elbow. If you are not sure, send us a photo of the stud – cone angle, thread and pitch – and we will confirm the matching 20791 part number.

What do the C and W suffixes mean?

• C marks a fine-pitch thread variant for the same nominal size: 20791-12-04C uses M12x1.25 where the standard row 20791-12-04 uses M12x1.5.
• W marks the construction used on the large sizes (dash -20 and -24) per the drawing. The W rows carry the same thread and cone seat as the standard construction; order the exact suffix from your drawing or the old fitting, and we will confirm the construction before dispatch.

74-degree cone seat elbow vs the other metric elbow families

The same metric thread size can appear in several cone systems, and only the matching angle seals:

20791 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).
• Sealing face: the 74-degree internal cone seat is machined, not cast, so the cone surface stays clean and concentric for a metal-to-metal seal.
• 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, A and C = lengths per the supplier drawing, H = overall elbow height per the drawing, S2 = swivel nut hex across flats. The row marked C uses the fine-pitch thread shown in the thread column; rows ending in W carry the large-size construction shown on the drawing.

Full dimensioned CAD drawings are available on request so your engineers can verify every length, the elbow height and the 74-degree cone seat 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 20791 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, because the rubber cover and tube lose capacity above about +100°C.

Which Fitting Series Do You Need: 20791 (Braided) or 20792 (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 20792 series as 20792-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 20791 part number carries the specification – thread, pitch, bore, construction – so purchasing can copy it straight into a PO:

20791 – 22 – 08

• 20791 = GB-series 74-degree cone seat 90-degree female elbow for braided hose
• 22 = thread nominal size (here M22x1.5)
• 08 = hose dash size (here DN12, 1/2-inch class bore)
• C suffix (20791-12-04C) = fine-pitch thread M12x1.25
• W suffix (large rows) = large-size construction per the drawing

Because one thread size can serve several hose bores and two pitches, always quote the full part number including any C or W suffix. 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 cone angle, pitch and construction, the same day.

Assembly Guide: Four Steps with the 74-Degree Cone Seat 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 cone seat clean and free of nicks.

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 74-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 74-degree cone with the 60-degree or 24-degree systems. A port with a different cone angle will not seal against a 74-degree cone even if the thread screws on.
• Never put PTFE tape or sealant on the thread of a metal-cone joint. The machined cones do the sealing, and contamination can score the seat.
• Never aim the elbow by bending the hose. If the nut cannot reach the correct orientation, re-check the part number or use an adjustable fitting.

Typical Applications

90-degree 74-degree cone seat female elbows serve the layouts of Chinese-specified machinery that combine the GB cone system with a compact right-angle turn:

• Agricultural machinery, tractors and implements
• Construction machinery and compact loaders
• Machine tools and general industrial hydraulics
• Hydraulic power units with GB-specified ports
• Replacement service for machines with unreadable or obsolete elbow part numbers

Wherever the male stud carries a 74-degree external cone and the routing demands a 90-degree turn, the 20791 series is the elbow to specify.

OEM Customization and Quality Traceability

For equipment builders and large maintenance programs, the 20791 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.
• Nut construction: standard or W large-size construction 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, 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 GB metric female 74-degree cone seat 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 74-degree internal cone seat, sealing metal-to-metal onto a male stud with a matching 74-degree external cone, in the GB-series cone family.

Q: Which male stud does it connect to? A: A male stud with a 74-degree external cone (37 degrees per side) – the GB cone geometry of the 10711 male series in this catalog. A 60-degree or 24-degree cone will not seal in this seat.

Q: What does the C suffix mean? A: C marks a fine-pitch thread variant: 20791-12-04C uses M12x1.25 where the standard row uses M12x1.5.

Q: What does the W suffix mean? A: W marks the construction used on the large sizes (dash -20 and -24) per the drawing, with the same thread and cone seat.

Q: What is the difference between 20791 and 20711? A: 20711 is the straight (inline) version of the GB 74-degree cone seat female end; 20791 is the 90-degree elbow version. Same port system and cone geometry.

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 20791 and 20792 series? A: 20791 is for wire-braided hose (1SN/2SN or R1AT/R2AT) and 20792 is for spiral hose (4SP/4SH style).

Q: Do I need thread tape or sealant? A: No. The machined 74-degree cones seal metal-to-metal. Tape on a straight metric thread adds nothing and can contaminate the system.

Q: What is the working pressure of these elbows? A: The assembly rating depends on the hose 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: 74-Degree Cone Seat Elbows with Confirmed Fit

Every 20791 GB metric female 74-degree cone seat hydraulic hose elbow in this range 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 cone angle, pitch and construction – a delivery date and a quote within one working day. Request samples first and trial-fit one on your own layout: the machined 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.