Custom Fiber Patch Cord Spec Template: Lock the Build Before You Order
A custom fiber patch cord specification fixes everything a factory needs to build the same cord every time: both connector ends, fiber and cable, polarity, overall and leg lengths with tolerances, labels, acceptance tests and packing. Write it once as a one-page spec (the template below), approve a sample against it, and reference the same spec number on every repeat order. That avoids the most common custom-order problems: undefined length reference points, unstated polarity and unclear test limits.
Scope of this guide: the engineering specification that defines a custom cord or MPO assembly and is approved before production. It is different from the fiber cable RFQ checklist, which lists the twelve fields needed to get a price; use the RFQ checklist to get a quote and this template to lock the build.
The Spec Template
Copy this table into your document and fill one column per part number.
| # | Field | What to write | Example |
|---|---|---|---|
| 1 | Spec / part number, revision | Your internal number and rev | HW-PC-0412 rev B |
| 2 | Assembly type | Patch cord, trunk, breakout, conversion harness | Duplex patch cord |
| 3 | End A connector | Type, polish, gender (MPO), boot colour | LC UPC, blue |
| 4 | End B connector | Same, separately | SC UPC, blue |
| 5 | Fiber | Grade and fiber standard | OS2, G.657.A2 |
| 6 | Fiber count | Per connector and total | 2 |
| 7 | Cable | Construction, diameter, jacket rating, colour | 2.0 mm duplex, LSZH, yellow |
| 8 | Polarity | Duplex A-to-B / A-to-A, or MPO Type A/B/C | A-to-B |
| 9 | Overall length and reference points | Measured from which points | 5.00 m, ferrule tip to ferrule tip |
| 10 | Length tolerance | Your requirement | +10 cm / −0 cm |
| 11 | Breakout legs (if any) | Leg length, stagger, furcation position | 0.5 m legs, no stagger |
| 12 | Insertion loss limit | Max per connector or mated pair, and wavelength | ≤0.35 dB at 1310/1550 nm |
| 13 | Return loss limit | Per polish | ≥50 dB UPC |
| 14 | End-face inspection | Standard and magnification | IEC 61300-3-35, 400x |
| 15 | Geometry | Interferometer sampling or 100% | Sampled |
| 16 | Labels | Content, position, both ends, format | Port ID both ends, 30 mm from boot |
| 17 | Packing | Per piece, per kit, carton marking | Bag per cord, 50 per carton by rack |
| 18 | Documents | Test report format, CoC, packing list | IL/RL per cord, PDF + CSV |
| 19 | Sample approval | Number of samples and approver | 2 pcs, signed by site engineer |
| 20 | Quantity and delivery | Per release | 400 pcs, 2 releases |
Fields That Cause the Most Rework
Length reference points
State what "5 m" means: ferrule tip to ferrule tip, or boot to boot. For breakouts also state where legs are measured from (the furcation, or the main connector). See MPO trunk length calculation.
Polarity
Duplex cords: A-to-B or A-to-A. MPO: Type A, B or C, plus key and gender at each end. Draw it if in doubt; see MPO polarity diagrams.
Test limits
"Low loss" is not a specification. Write the number, the wavelength and whether it is per connector or per mated pair. See insertion loss vs return loss.
Labels
Give the label text as a list or spreadsheet that maps every part to its port IDs. See fiber cable labeling.
From Spec to Repeat Orders
- Send the spec with your RFQ. Gaps are flagged in the quotation.
- Approve a sample. Check it against every line; sign the revision.
- Freeze the revision. Production builds to the signed revision; changes get a new revision.
- Reorder by spec number. Repeat orders reference the same number and need no re-checking.
See OEM/ODM project workflow and the sample program.
Frequently Asked Questions
What should a custom fiber patch cord specification include?
Both connector ends, fiber grade, fiber count, cable and jacket, polarity, length with reference points and tolerance, loss limits, inspection, labels, packing, documents and sample approval.
How is a spec template different from an RFQ?
An RFQ gives enough information to price an order. A specification defines the exact build so every batch is identical, and is approved with a sample before production.
How should cable length be specified?
State the length, the reference points (usually ferrule tip to ferrule tip) and the tolerance; for breakouts, also leg length and where it is measured from.
Do I need a drawing for a custom cord?
Not for simple duplex cords; the template is enough. For breakouts, harnesses and multi-leg assemblies a simple drawing avoids misreading.
Is there a minimum order for custom builds at Huawellux?
For special/custom requirements, MOQ is 2 km of fiber length. Standard listed patch cords have no formal MOQ.
Build It with Huawellux
Huawellux builds custom LC, SC and MTP/MPO assemblies to customer specifications, including OM3 and other grades not listed online.
Huawellux's specification for MPO and MTP® assemblies is insertion loss ≤0.35 dB for single-mode and multimode, with return loss >60 dB single-mode (OS2, APC) and >30 dB multimode (OM3/OM4/OM5). LC and SC patch cords are listed at insertion loss ≤0.35 dB and return loss ≥60 dB (single-mode APC), ≥50 dB (single-mode UPC) and >30 dB (multimode) on each product page. Every Huawellux product receives end-face visual inspection under a 400x video microscope and is tested for insertion loss (IL) and return loss (RL) before it ships. Interferometric end-face geometry (fiber height, coplanarity, end-face angle and radius) is checked by sample-based testing in standard production, and 100% interferometer testing of a batch is available on request. Dust caps are fitted on every connector, and a formal test report is available on request.
Huawellux replies to inquiries within 24 hours. Listed standard products are prepared in 1–7 business days. Custom orders typically take 1–5 business days to complete production, with final timing confirmed case by case in the quotation. For special/custom requirements, MOQ is 2 km of fiber length. Standard listed patch cords have no formal MOQ. Labels printed to your own numbering scheme are free. The sample fee is credited against the bulk order. Standard products carry a one-year limited warranty under the published returns and warranty policy.
- Start with the fiber cable RFQ checklist, then send your spec: Request a Quote
- See listed options: LC/SC patch cords, MPO patch cables
MTP® is a registered trademark of US Conec Ltd.