20511TRW Metric Female 24-Degree Cone O-Ring HEAVY-Series ONE-PIECE Hydraulic Hose Fittings

One-piece heavy female 24-degree cone O-ring hydraulic hose fittings deliver the biggest female ends in the O-ring cone family ready to crimp: the heavy-series sleeve is pre-fitted on the tail, the heavy-series O-ring sits in the 24-degree cone seat, and the swivel nut turns freely on top. The 20511TRW series is the one-piece version of the 20511 heavy female, with the same 19 part numbers from DN6 (-04) to DN40 (-24), female metric threads M14x1.5 to M52x2 mapping to DIN heavy-series tube sizes from 6 to 38 mm, for wire-braided hose. If your shop builds heavy female ends onto 24-degree cone O-ring male studs – or your drawings call up ISO 12151-2 / DIN 3865 O-ring cone connections in the heavy schedule – this page covers the one-piece option, the suffix logic and the O-rings that actually match heavy cone geometry.

Why Choose One-Piece Heavy O-Ring Cone Fittings

• Pre-fitted sleeve, pre-fitted O-ring, free-turning nut. The ferrule is already on the tail and the heavy-series O-ring is already in the cone seat, so the fitting arrives complete.
• The benefit grows with size. On DN32 and DN40 heavy ends the sleeve is heavy and awkward to hold in alignment; the factory pre-fit removes exactly that handling step.
• 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.
• Heavy (H.T.) thread schedule. DIN heavy-series threads, M14x1.5 for a 6 mm tube class up to M52x2 for 38 mm, for the higher-pressure systems that specify them.
• 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. 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.

One-Piece vs Two-Piece on the Heavy Female Side

A heavy female hose end is the heaviest combination in the female range: a large stem, a long sleeve, a swivel nut and an O-ring, assembled at the top end of the size table. Every part handled separately on a bench is an error mode, and the parts only get heavier as the bore grows.

The 20511TRW one-piece version removes the handling problem at the source. The sleeve is already fitted on the stem and the O-ring is already seated in the cone, so the operator inserts the hose, crimps and verifies. The sleeve is always at the correct depth and orientation, the O-ring is always present, and results are consistent from one operator to the next – which matters most on the big sizes, where a misaligned sleeve is expensive to scrap.

Same port end as the two-piece 20511

The 20511TRW female end is dimensionally the same ISO 12151-2 / DIN 3865 heavy O-ring cone series as the two-piece 20511: same threads, same cone seat, same heavy-series O-ring sizes, same swivel nut hex. The difference is on the hose side, where the sleeve comes integrated. If your drawing specifies the 20511 series, the -RW one-piece version is a drop-in on the port side.

What do the RW and TRW suffixes mean?

• RW marks the one-piece construction (sleeve pre-fitted on the stem) for the sizes listed with it.
• TRW marks the one-piece construction combined with the alternate nut retention design shown on the 20511-T drawing – the same sizes that carry a T suffix in the two-piece 20511 table.
• Order the exact suffix from your drawing or the old fitting, and we will confirm the construction before dispatch.

The heavy O-ring is not the light O-ring

The cone seat geometry differs between schedules, so the O-ring for a heavy female is a different size than the light-series O-ring at the same nominal thread. Examples from the two tables: M22x1.5 takes O11.0x2.0 in the heavy series but O12.0x2.0 in the light; M30x2 takes O16.3×2.4 in heavy but O20.0x2.0 in light; M52x2 takes O33.3×2.4 in heavy but O38.0x2.5 in light. Every 20511TRW part number lists its own matched O-ring – never substitute a light-series seal.

20511TRW 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 to keep the thread, the cone seat, the sleeve and the nut 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 – these are the heavy-series sizes, not the light-series sizes.
• Sleeve: integrated with the stem as one delivered assembly, plated to match the body.

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 = engagement length from the end of the shell to the sealing face, C = depth of the internal sealing shoulder, S2 = swivel nut hex across flats (dimension definitions per the supplier drawing). RW = one-piece construction; TRW = one-piece with the alternate nut retention design.

Note: the last row appears in the source image with the part number misread as “20511-45-20TRW” against thread M52x2; the part number 20511-52-20TRW is used here, matching the two-piece 20511 table and the -20 dash. Confirm the printed part number with the factory before large orders.

Full dimensioned CAD drawings are available on request so your engineers can verify every length, 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 20511TRW fitting depends on the hose you pair it with and the crimp quality. The heavy schedule is specified where the circuit or the port standard demands it – typically the higher-pressure classes of the size range. Wire-braided hydraulic hose in this range commonly operates from roughly 80 bar (large bore) up to 400 bar (small bore 2SN). Send us your hose specification and we will confirm the working pressure, burst margin and the crimp setting 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: 20511TRW (Braided) or 20512TRW (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 20512 series as 20512-XX-XXTRW. 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 20511TRW part number carries the whole specification – thread, bore, O-ring and construction – so purchasing can copy it straight into a PO:

20511 – 30 – 12RW

• 20511 = 24-degree cone O-ring heavy-series female for braided hose
• 30 = thread nominal size (here M30x2, DIN heavy-series class for 20 mm tube)
• 12 = hose dash size (here DN20, 3/4-inch class bore)
• RW = one-piece construction; TRW = one-piece with alternate nut retention design
• O-ring = O16.3×2.4 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, send us a photo of the nut end, the hose side and the male cone stud it connects to, and we will confirm the matching part number – including the correct heavy-series O-ring and suffix – the same day.

Assembly Guide: Four Steps with the Pre-Fitted Sleeve

The one-piece design shortens the heavy female-end routine to four steps, with the sleeve and the O-ring already in place.

Étape 1 – Coupez le tuyau à angle droit. Use a sharp hose cutter or cutoff saw. A square, clean cut lets the pre-fitted sleeve grip the cover evenly. A beveled or ragged cut is the most common cause of pull-out failures.

Step 2 – Prepare the insert depth. The hose must reach the full insertion depth inside the one-piece fitting. Measure once against the fitting or the crimp die, and use that depth on every assembly of the same size.

Étape 3 – Lubrifiez et insérez. Apply a thin film of assembly lubricant to the hose bore and the barb zone, then push the hose into the pre-fitted sleeve and over the stem until it bottoms out. Wipe away excess lubricant. Keep the O-ring and the cone seat clean.

Étape 4 – Sertir et vérifier. Crimp the pre-fitted sleeve 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 mix the heavy and light schedules. A heavy-series male stud needs a heavy-series female, and the light-series O-ring at the same nominal thread is the wrong size for a heavy female.
• Never mix the O-ring cone joint with the plain metal cone joint. A male stud designed for a metal-cone female may not match the O-ring geometry of this nut, and vice versa.
• Never re-use a fitting that has already been crimped, and never put PTFE tape or sealant on the thread. The one-piece sleeve is made for one crimp cycle.

Typical Applications

The heavy-series O-ring cone (DKOS-type) joint is specified on higher-pressure European-standard systems and on equipment that demands the heavy thread schedule. The one-piece female version earns its place wherever heavy female ends are made in volume:

• Hose assembly shops and distributors producing heavy O-ring cone female ends in batches
• Hose assemblies onto heavy-series 24-degree cone O-ring male studs on pumps, valves and cylinders
• European-specified machines and their global service networks
• Machine tools, presses and injection molding machinery
• Construction, mining and material handling equipment
• Hydraulic power units and general industrial hydraulics

Wherever the mating stud carries a heavy-series 24-degree cone O-ring joint, the 20511TRW series is the female hose end – complete with sleeve, heavy O-ring and swivel nut in one part number.

OEM Customization and Quality Traceability

For equipment builders and large maintenance programs, the 20511TRW 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.
• Packaging and kitting: custom labels, barcodes, poly-bag or box quantities, and pre-kitted assemblies 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.

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.

Emballage et logistique

Standard export packing: fittings are individually poly-bagged or boxed to protect the pre-fitted sleeves, O-rings, threads and cone seats, 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 one-piece heavy female 24-degree cone O-ring hydraulic hose fitting? A: It is a crimp-style female hose end in the heavy (H.T.) thread schedule where the sleeve is pre-fitted on the stem and the heavy-series O-ring is pre-seated in the 24-degree cone. The operator inserts the hose and crimps – no separate ferrule or O-ring to handle.

Q: What is the difference between 20511TRW and the two-piece 20511? A: The port end is dimensionally the same. The difference is on the hose side: the 20511TRW has the sleeve pre-fitted, so there is no separate ferrule to align and the O-ring is already in place.

Q: What do the RW and TRW suffixes mean? A: RW marks the one-piece construction. TRW marks the one-piece construction combined with the alternate nut retention design – the sizes that carry a T suffix in the two-piece 20511 table.

Q: Is the heavy-series O-ring the same as the light-series O-ring? A: No. For example M30x2 takes O16.3×2.4 in the heavy series but O20.0x2.0 in the light series. Each part number lists its own matched O-ring.

Q: What is the difference between 20511TRW and 20411TRW? A: 20511TRW is the heavy-schedule version and 20411TRW is the light-schedule version of the one-piece O-ring cone female. Same concept, different thread schedule, different O-rings.

Q: What is the difference between the O-ring cone and the metal cone heavy females? A: The O-ring cone female seals through its O-ring with metal backup. A metal-cone female (the 20511C-type multiseal construction) seals metal-to-metal on the bare cone. Match the female to the joint type of the male stud.

Q: What is the difference between 20511TRW and 20512TRW? A: 20511TRW is for wire-braided hose (1SN/2SN or R1AT/R2AT) and 20512TRW is for spiral hose (4SP/4SH style).

Q: Do I need thread tape or sealant? A: No. The O-ring in the cone seat does the sealing. Tape on a straight metric thread adds nothing and can contaminate the system.

Q: Can a one-piece fitting be re-used after crimping? A: No. The sleeve is made for one crimp cycle. Cut the assembly off and use a new fitting.

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: One-Piece Heavy O-Ring Cone Female Fittings with Confirmed Fit

Every 20511TRW one-piece heavy female 24-degree cone O-ring hydraulic hose fitting in this range ships with its sleeve and heavy-series O-ring in place, is made to controlled dimensions, inspected before packing and backed by batch traceability. Send us your hose type, thread size and a photo of the male cone stud it connects to, and you will get a confirmed part number, the correct suffix and O-ring, a delivery date and a quote within one working day. Request samples first and run them through your own crimper – on the big sizes, the pre-fitted sleeve is the fastest way to see what one-piece construction does for your reject rate. We make sure the fitting, hose and crimp work as one leak-free assembly.