Metric 74 Degree Cone Flared Sleeve Adapter NB500-Q (GB/T 5646 Flared Tube Sleeve)

Why This Metric 74 Degree Cone Flared Sleeve Adapter NB500-Q Passes the Compliance Gate

The metric 74 degree cone flared sleeve adapter NB500-Q is the flared sleeve of the GB/T 5646 system, and it is the part that actually touches the tube. It slides over the tube behind the flare, and when the matching NB200-Q nut is tightened the sleeve pushes the 74 degree flare onto the adapter cone, producing a metal-to-metal seal.

The sleeve is therefore the part that decides whether the joint holds. A nut with no sleeve, a sleeve of the wrong size, or a sleeve fitted the wrong way round all leave the flare unseated, and no amount of torque will recover the joint. Because the sleeve is pressed against the flare every time the joint is tightened, it is also the part that is normally renewed rather than re-used.

Three facts matter when ordering:

• The sleeve is selected by the tube outside diameter, not by the thread. The published table lists the tube size, the sleeve dimensions, and the nut it is dimensionally paired with.
• The sleeve and its nut must come from the same tube size row. NB500-14Q belongs with NB200-22Q on a 14 mm tube, and no other combination is correct.
• One nut row serves two sleeve-compatible cases: a 20 mm tube sleeve NB500-20Q is listed with both NB200-30Q (M30X1.5) and NB200-30EQ (M30X2).

Core Advantages

1. Published nut pairing. Every sleeve row is listed with the nut it fits, so a joint can be ordered complete in one step.
2. Full flared tube range. Eleven published sleeve sizes from a 5 mm tube to a 25 mm tube.
3. Correct 74 degree geometry. The sleeve is dimensioned for the 74 degree flare system, not for a bite-type ring.
4. Renewable wear part. Replacement sleeves keep repaired joints reliable without changing the nut or the adapter body.
5. Batch traceability. Heat number, production batch and inspection records are tied to each carton.
6. OEM marking and kit packing. Customer numbers can be laser marked, and sleeve and nut can be packed as a matched kit.

Technical Specifications

What Is a Metric 74 Degree Cone Flared Sleeve Adapter?

The metric 74 degree cone flared sleeve adapter NB500-Q is the sleeve of the GB/T 5646 flared tube system, the companion part to the GB/T 5647 nut. In this system the tube end is cut square, deburred, and flared to 74 degrees; the nut is then slid on, the sleeve follows, and the nut is tightened so that the sleeve forces the flare onto the adapter cone.

The sleeve does not seal on a thread and is not welded. The sealing surface is the flared tube end on the cone, and the sleeve is the load path that presses it there.

Dimensional Data

Full Dimension Table (Part Number Matrix)

Thread Size and Dash Chart

Material and Heat Treatment

The series drawing states no material grade, so the following describes typical production and is confirmed on the purchase order.

Working Pressure and Operating Envelope

The published drawing carries no pressure column, so no pressure rating is claimed for this series. Working pressure of a finished flared joint is governed by the port standard together with the tube and sleeve grade selected, and the finished assembly is only as strong as its weakest member.

• The flare sleeve carries the clamping load of the joint, so it must be replaced whenever the flare has been re-cut or the tube replaced.
• Data sheets referenced to the flared tube system standards (GB/T 5646 and GB/T 5647) can be supplied on request.
• Each batch is inspected and packed with batch records as part of the standard HENGHUA fitting workflow.
• For safety-critical circuits, rate the assembly from the lowest rated element: tube, flare, sleeve, nut or adapter body.

Temperature Range

A typical service window for a steel flared joint with a metal-to-metal cone seal is -40 degrees C to +120 degrees C. The real limit is set by the tube and by the connected hose or adapter body, not by the sleeve. Outside that window, specify the complete joint material set and confirm with our engineering desk.

How to Read the Part Number Matrix

The metric 74 degree cone flared sleeve adapter NB500-Q is coded with a family block, a two digit tube size and a system letter.

NB500 identifies the GB/T 5646 flared tube sleeve family, the number is the tube outside diameter in millimetres, and Q marks the 74 degree cone flared system.

Selection and Ordering

Selection Checklist / Decision Table

Confirm the following points before ordering the metric 74 degree cone flared sleeve adapter NB500-Q.

Cross Reference Service

Send a photograph of the worn sleeve with the tube outside diameter and the sleeve outside diameter, and we will identify the correct row and its matching nut free of charge, normally within 24 hours. We do not copy or re-label another company’s brand; we match the interface and the drawing.

Packaging and Logistics

Individual poly bags with size labels or bulk bags per size, carton marking with batch and heat number, mixed-size consolidation in one shipment, and air freight or courier for urgent requirements. Sleeves and nuts can be supplied as matched kits on request, and material certificates travel with the goods when requested.

Installation and Fitment Guide

Step-by-Step Assembly

1. Cut the tube square. Measure the cut with a square; an angled cut produces a flare that does not sit squarely on the cone.
2. Deburr inside and outside. Remove the burr so the sleeve can slide freely and the flare forms without cracking.
3. Anneal hard tube ends where required. If the tube grade or the drawing calls for annealing before flaring, do it before the flare is formed.
4. Slide the nut on first, then the sleeve. The nut must go onto the tube before the flare is made; the sleeve follows, in the orientation shown in the drawing.
5. Flare the tube end to 74 degrees with a tool that produces the correct cone angle and flare diameter. Reject a cracked or split flare and start again.
6. Seat and tighten. Push the tube forward so the flare contacts the adapter cone squarely, then tighten the nut to the published torque with a backing wrench on the adapter body, and leak test at working pressure.

Tube End Requirements

Torque and Sealing Notes

• Use the torque figure published for the thread size and tube grade; the sleeve is compressed during tightening and must not be over-loaded.
• The seal is made by the flared tube end on the 74 degree cone, so no sealant is applied to the flare or to the sleeve.
• The nut must run down freely by hand before final torque; a binding nut indicates a cross thread, the wrong pitch, or a sleeve that has not seated.
• Fit a new sleeve whenever the tube end has been re-flared.

Installation Warnings

• ✔ Confirm the sleeve and the nut come from the same tube size row.
• ✔ Confirm the flare angle is 74 degrees before assembly.
• ✔ Hold the adapter body with a backing wrench while tightening the nut.
• ✔ Re-test at working pressure after any re-torque.
• ❌ Never assemble a flared joint without the sleeve; the nut alone cannot clamp the flare.
• ❌ Never fit the sleeve backwards or use a sleeve from another tube size.
• ❌ Never re-use a sleeve that has been crushed, scored or stretched.
• ❌ Never mix this sleeve with a bite-type nut or a 60 degree cone adapter body.

Applications and Industries

The metric 74 degree cone flared sleeve adapter NB500-Q is used wherever flared tube joints are made, repaired or stocked as matched pairs with the nut.

Industry tags: hydraulics, tube fabrication, repair workshops, test benches, mobile machinery, marine, mining, plant maintenance.

Common Fitting Faults to Avoid

OEM Customization and Quality Traceability

HENGHUA produces hydraulic adapters, flared tube components and complete hose assemblies alongside its Globhose hose programme, so the metric 74 degree cone flared sleeve adapter NB500-Q can be supplied alone or as a matched sleeve and nut kit.

• Laser marking and private labelling with customer logo, part number and lot code.
• Custom surface treatment including trivalent zinc and Zn-Ni.
• Drawing or sample based production, with quotation typically within 24 hours.
• Batch traceability from heat number to carton label.
• Testing and documentation: material certificates and BV or SGS inspection on request.

FAQ

Q: What is the difference between the NB500-Q sleeve and the NB200-Q nut? A: The sleeve contacts the tube behind the flare and presses it onto the 74 degree cone, while the nut provides the clamping force through its thread. Both are needed, and they must be matched by tube size.

Q: Can I fit the NB500-Q sleeve without the nut? A: No. The sleeve only deforms and clamps when the nut pulls it forward onto the flare, so the two parts always work as a pair.

Q: How do I know which nut fits this sleeve? A: Read the MATCHING NUT column. For example NB500-14Q pairs with NB200-22Q on a 14 mm tube, while NB500-20Q pairs with NB200-30Q or NB200-30EQ on a 20 mm tube.

Q: What does the tube end need before assembly? A: A square cut, a deburred end, annealing where the tube grade requires it, and a 74 degree flare that is concentric, uncracked and matched to the tube size. Welding does not replace the flare, because the sleeve seals on the flare.

Q: Which way round does the sleeve go? A: The sleeve is fitted behind the flare in the orientation shown in the series drawing, with the nut already on the tube. Fitting it backwards prevents the flare from being pressed onto the cone.

Q: What pressure does the joint hold? A: The drawing carries no pressure column, so no rating is claimed. The limit depends on the tube wall, the flare quality and the sleeve, and the assembly is only as strong as its weakest member.

Q: What material is the sleeve made from? A: Typical production is carbon steel with trivalent zinc plating; stainless steel 304 or 316L is available on request. Confirm the grade on the purchase order.

Q: Where can I buy the metric 74 degree cone flared sleeve adapter NB500-Q with matching nuts? A: Order the sleeve and nut together by PART NO., for example NB500-14Q with NB200-22Q, and state the material or coating and quantity. Quotations are answered within 24 hours and standard sizes ship in 7 day batches.

Solicitar um orçamento

Send the tube outside diameter, the matching nut PART NO. if known, the material or coating and the quantity, and we will confirm the correct row of the metric 74 degree cone flared sleeve adapter NB500-Q table, normally within 24 hours. Order the sleeve with its nut and the flared tube joint arrives as a complete matched set; if you are replacing unmarked parts, send a photograph with the tube and sleeve diameters and we will identify both free of charge.

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