LC-QR usually means a quick-release LC connector, an ordinary LC with a push-pull tab, pull-boot or extended latch so it can be released in a dense panel. It is a supplier label, not a standard. The ferrule, loss and adapter fit stay those of a normal LC, so specify the release feature by description or drawing.
What the name LC-QR is being used for
LC-QR is not a connector standard. There is no IEC or TIA document that defines an interface called LC-QR. The letters QR are generally read as quick release, and the name is used by some suppliers for an LC connector whose housing is built to be unplugged more easily, typically with a push-pull tab, a pull-boot or a latch that can be released without a fingertip reaching in beside the neighbouring plug. The part you mate with is still an ordinary LC, with the same 1.25 mm ferrule and the same adapter.
That matters for a buyer, because it means two things. First, an LC-QR plug should plug into any standard LC adapter or transceiver, since the optical interface is the LC interface in IEC 61754-20 and TIA-604-10. Second, what "QR" means in detail depends on the supplier. One maker's LC-QR may be a push-pull tab, another's a longer latch lever, and a third's a shortened body. So the safe approach is to describe the behaviour you want on the drawing, and to treat the name only as a pointer.
The sections below cover the quick-release features found on LC plugs, what they change, and how to word an order. The page sits under our overview of fibre connector types. Radix Fibrotech builds patch cords in Pune from the buyer's drawing, and a given quick-release housing is checked against that drawing before we say yes. Send it and we reply with what we can build.
The problem quick release is meant to solve
A standard LC has a small latch on the top of the plug, shaped like an RJ-45 tab. To pull it out of an adapter you press the tab and pull the plug. In a loose rack that is easy. In a dense panel it is not, because the adjacent plugs are packed 6.25 mm apart, the tab is under a neighbour's boot, and a thumb and finger cannot get in. Technicians end up pulling on the cable or the boot, and that can pull the fibre out of the ferrule or break the latch.
Quick-release designs address one or more of these things:
- A tab that extends back along the cable so it can be pressed and pulled from behind the body of the plug.
- A boot that moves with the latch, so pulling the boot releases the connector.
- Colour-coded or labelled tabs to identify the fibre without handling the neighbours.
- A thinner or shorter profile, which leaves more finger room in the panel.
These are the same ideas used in the push-pull tab LC patch cords and in uniboot LC patch cords. If the product you are looking at is described as LC-QR, ask the supplier which of these it is.
How LC pitch and finger room work out
The dimension that creates the access problem is the pitch, the centre-to-centre spacing of the LC plugs. A standard LC duplex adapter holds two plugs 6.25 mm apart, so a duplex pair takes 12.5 mm of panel width. Panels are built to this pitch to get density.
Worked example, assumed values. A 1U panel with a usable width of 440 mm and LC duplex adapters at 12.5 mm per duplex pair.
- 440 divided by 12.5 is 35.2, so at most 35 duplex positions across the row, ignoring frame and fixings.
- Allow for the frame and spacers, and a real panel might fit 24 to 32 duplex positions per row. The panel maker states the number for each product.
- The plug body of a standard LC is narrower than the 6.25 mm pitch, but only by a millimetre or so (check the plug data sheet). No fingertip fits in a gap that small.
So in a fully filled row there is no gap to reach a latch from the side. The release has to be reachable from above or from behind. This is the reason quick-release and push-pull designs exist, and the reason many high-density panels are built with removable cassettes rather than fixed adapters. Where you can open the cassette out, the problem is smaller. In a fixed panel, quick-release plugs matter more.
Check the dimensions yourself. The plug width and the panel pitch are on the data sheets, and a sample plug in a sample panel settles it faster than any table.
What a quick-release LC does not change
It helps to be exact about what stays the same, because buyers sometimes expect an LC-QR to behave differently optically.
| Item | Standard LC | LC with quick-release housing |
|---|---|---|
| Ferrule diameter | 1.25 mm | 1.25 mm |
| Fibre type | Single-mode or multimode | Same options |
| Polish | PC, UPC or APC | Same options; the polish is on the ferrule, not the housing |
| Insertion loss | Depends on ferrule and fibre grade | Depends on the ferrule and fibre grade, not on the release feature |
| Adapter and transceiver fit | Standard LC | Standard LC, if the housing is within the dimensions of the interface |
| Polarity | A-B duplex | The same, but check that the clip or tab does not block the reversing of the duplex clip |
Optical performance comes from the ferrule and the fibre, as the table shows. Loss and return loss are set by the polish, the geometry and the cleanliness, as the guide to PC, UPC and APC polish explains. A quick-release housing neither adds loss nor removes it. Ask for the attenuation figures in the quote and ask how the cord is tested, as set out in how fibre patch cords are tested.
Compatibility checks before you buy
Because the housing is where suppliers differ, the checks are mechanical.
- Adapter fit. Plug a sample into the actual adapters or transceivers it will use. A housing that is slightly long can foul the cage or the neighbouring port.
- Latch strength. Pull the plug in the direction of the cable, gently, to confirm it holds. The retention test in the connector standards (IEC 61300-2-4) defines the force and the method, and the supplier can state the result.
- Release action. Test with the panel full, not on an empty bench. The test is whether a technician can release one plug without disturbing the neighbours.
- Duplex clip and polarity. Many duplex LC cords use a clip that holds the two plugs together and can be reversed to swap transmit and receive. Check the quick-release feature still allows this.
- Boot and cable. The boot must suit the cable diameter. See 2 mm vs 3 mm patch cord cable. A pull-boot design transmits the pull to the latch, so it needs a boot that is stiff enough not to buckle.
- Bend relief. The release design should not reduce the strain relief on the cable. A bend that is too tight at the boot is a standard cause of damage; see bend radius for fibre cable.
- Cleaning access. The end face still has to be inspected and cleaned, and a plug that will not accept a cleaning tool is a nuisance. The method is in the guide to end-face cleaning and inspection.
Where quick-release LC makes sense
| Setting | Why it helps | Notes |
|---|---|---|
| High-density patch panels, fixed adapters | Plugs can be released without reaching between neighbours | Match the panel pitch and check finger room with the panel full |
| Switch front panels with tight cages | Pull-tab or pull-boot lets you release without touching nearby ports | Check the module cage dimensions |
| Moves-adds-changes in busy data centres | Faster, less handling of other cords | The saving shows up in time per move |
| Test benches and labs | Repeated plugging and unplugging | Wear on the latch matters; ask for mating cycle data |
| Broadcast and event racks | Quick re-patching in short windows | Consider locking connectors where cords may be tugged |
Elsewhere it makes less difference. A cord that is plugged in once and left for years does not need a quick-release housing, and a standard LC is smaller and cheaper to stock. In a frame where cords are routed behind a door and released by opening the cassette, a quick-release feature adds little.
For the underlying connector, the LC connector guide covers the dimensions and history, and LC vs SC connector compares it with the connector it largely replaced. The version with a tab fitted to a standard body is described in LC to LC patch cords.
Wording the order line
Because LC-QR has no standard definition, do not order by that name alone. Describe the cord completely. A complete line looks like this:
- Connector at each end: LC duplex, with polish (UPC or APC) and the fibre type and grade.
- Release feature: push-pull tab, pull-boot or other, with a drawing or a sample part number from the supplier you want to match.
- Tab colour or label, if you use colour for identification. See fibre colour codes.
- Cable: diameter, jacket and colour.
- Length and tolerance.
- Duplex clip: fixed or reversible, and the polarity you need.
- Tests: wavelengths, limits and the report you need.
If you already have a sample cord whose housing you want to match, send a photograph and the part number. The page on how to write an RFQ for fibre assemblies gives the complete list of headings for a quote request, and you can send it on the request a quote page. For housing details outside the common range, send a drawing and we reply with what we can build.
Mistakes buyers make with the LC-QR name
- Treating LC-QR as a standard. It is a supplier label. Two products with that name may not share a housing.
- Assuming the optical performance differs. The release feature is mechanical. Loss comes from the ferrule and fibre.
- Testing on an empty panel. The advantage only shows when the panel is full.
- Mixing housings in the same panel. Different bodies have different lengths, and a mixture can leave some plugs hard to reach.
- Ordering the tab but not the polarity. A quick-release feature does not specify which fibre is which. Write the polarity down.
- Pulling the cable to release a plug. If the design relies on the boot to release, use the boot, not the jacket.
When a quick-release LC is not what you need
A quick-release feature is a convenience, not a requirement. If you plug in once, leave the cord and rarely touch the panel, choose a standard LC. If the cord will be tugged by traffic, or used in a vibrating or outdoor setting, the better answer is a locking or sealed connector, not an easier-to-release one. See IP67 and IP68 fibre connectors for sealed styles, or the Harting LC connector guide for a rugged LC housing.
If your real problem is that the panel is too dense, a better fix might be a different panel: one with sliding trays or cassettes that pull out for access. And if the aim is to reduce the number of cords, a multi-fibre approach such as MPO with breakouts or cassettes may do more than any LC housing change; see MPO vs LC in the data centre.
Related products and guides: Related ranges: LC.
Questions buyers ask
What is an LC-QR connector?
LC-QR is a supplier name, generally read as quick-release LC. It is an LC connector with a housing that is easier to release in dense panels, such as a push-pull tab or pull-boot. It is not a separate standard, and the optical interface is the ordinary LC interface with a 1.25 mm ferrule.
Does LC-QR fit a standard LC adapter?
It should, since the mating part is the standard LC. Check the housing dimensions against the adapter or transceiver cage on a sample, because some housings are a little longer or wider than a plain LC. Buy a few samples before a large order.
Does a quick-release housing change insertion loss?
No. Insertion loss and return loss come from the ferrule, the fibre grade, the polish and cleanliness. The housing is mechanical. Ask the supplier for attenuation limits and the wavelengths used to test them, as for any LC cord.
Are LC-QR and push-pull tab LC the same?
Often they are close, but the name is not defined, so do not assume. Push-pull tab is a descriptive term for a tab that extends the latch backwards. Ask the supplier what their LC-QR release mechanism is, or send a sample or drawing for a quote.
Can the polarity be changed on a quick-release LC duplex cord?
On many duplex LC cords the clip that joins the two plugs can be reversed to swap transmit and receive. Whether a quick-release version allows this depends on the design. State on the order whether you need reversible polarity or a fixed A-B arrangement.
What panel pitch do LC connectors use?
Adjacent LC plugs sit 6.25 mm apart, so a duplex pair takes 12.5 mm of panel width. The plug body is only a little narrower than that, which leaves almost no gap between plugs in a full row. That is why release tabs and cassettes are used.
When should I choose a standard LC over a quick-release one?
Choose standard where cords are rarely moved, where space is not tight or where you want the smallest, simplest part. Choose quick-release where technicians patch often in a full, dense panel. Choose locking or sealed housings where the cord faces vibration or weather.
Can Radix make LC cords with a quick-release housing?
Whether a given quick-release housing can be built depends on the drawing. Send a drawing or a sample part number by form, phone or WhatsApp, and Radix replies with what we can build.
Is LC-QR the same as an LC uniboot connector?
Not necessarily. Uniboot describes a duplex LC with both fibres in one round cable and one boot. Quick release describes how the latch is released. Some uniboot connectors also have a pull tab, and some quick-release LCs are on two separate cords, so name both features on the order.