What to send in a cable assembly RFQ

Someone emails a photo of a cable on a bench, or a PDF with no revision, or a BOM that says “Molex connector, or equivalent.” Then both sides spend a week asking the same three questions. The buyer thinks the shop is stalling. The shop is trying not to guess the pinout.

If you build equipment in the U.S. and you outsource cable assemblies, the RFQ is the first place the program either gets honest or starts leaking time.

This is the pack we actually use when an OEM wants a number they can take to purchasing.

Start with the drawing you have, not the drawing you wish you had

A controlled 2D assembly drawing is still the best document. Lengths, breakouts, connector orientation, notes, tolerances. If you have that, send it. We quote primarily from the 2D drawing, with the 3D model used to understand routing, clearances, and form where needed.

If you do not have a released drawing, send the next best thing. In order, that is usually:

1. A marked-up print of the last revision, even if it is messy
2. A wiring diagram or pinout table
3. A sample, or clear photos of both ends plus a tape measure on the length
4. A paragraph that says what the cable does and what it plugs into

A screenshot pasted into Word is the one that burns people. We cannot reliably read small markings, verify dimensions, or trust missing drawing information, and we will not pretend we can.

You do not need a perfect package to start. You do need enough that an engineer can stop guessing.

Put a revision on everything

This sounds petty until two quotes come back for different cables.

If the drawing is Rev C and the BOM is Rev B, say so. If purchasing is still working off an older print, say that too. We would rather quote the revision you intend to buy than the file that happened to be in the email.

Same rule for part numbers. “J1 connector” is not a part number. “TE 1-776267-1 housing, with the specified contact part number” is a part number. If a contact or seal is a different dash number, that changes cost and lead time. It also changes whether the thing actually clicks into the mating half on your board.

“Or equivalent” on a sealed automotive or medical connector is how you get a quote that looks cheap and a first article that may not mate, seal, or meet the required qualification.

The BOM is where quotes go wrong

A usable BOM names the manufacturer and the exact part, not just the commodity.

Useful lines look like this:

• Cable or wire: type, gauge, color, UL style if you have one, jacket/insulation specification, length
• Connectors: manufacturer, housing, terminals, seals, cavity plugs
• Protection: braid, split loom, heat shrink, overmold material if you already chose it
• Labels: content, format, where they sit
• Hardware: clips, grommets, backshells, strain relief

If a line is still open, mark it open. “Shield termination TBD” is fine. Leaving it blank is how two shops assume two different things and you compare prices that are not for the same build.

Approved alternates belong on the BOM, not in a side email. If Molex is the preferred source and you will accept TE as an alternate, write it down. If you will not, write that down too.

Pinout, or we are quoting a shape

A cable can look right and be electrically wrong.

Send a pin-to-pin table. From-to is enough. Color to cavity is enough. What we cannot use is “same as the sample” when the sample has no markings and the mating connector is already potted into a housing in California.

If the assembly is a multi-branch harness, the pinout matters more, not less. Branch length without a from-to is just a sketch.

Tell us how it lives in the machine

Shops can build a pretty cable that dies in the field. That is not a quote problem. That is a missing application note.

A short block is enough:

• Power, signal, or mixed
• Voltage and current, even if approximate
• Temperature, oil, washdown, UV, flex, vibration, if any of those are real
• Humidity or moisture, chemicals, mating/unmating cycles, if they apply
• Indoor panel versus something that sees weather or motion
• Mating parts on the equipment side, if you already bought them

You do not have to write a novel. “48 V, panel interior, no flex, mates to an existing Phoenix Contact terminal block” is a usable sentence. “High reliability interconnect for harsh environment” is not.

Say what you want tested, in writing

If the drawing is silent, the test list is easy to under-specify. For a basic cable assembly, that may mean 100% continuity testing plus visual and dimensional inspection. If your program requires more, specify it on the RFQ. That may be enough for a panel jumper. It may not be enough for a medical-device, high-voltage, or other regulated program.

If you need hipot, pull force, insulation resistance, or a first-article report, put it on the RFQ. If your program requires specific lot traceability or documentation with the shipment, say that. If IPC/WHMA-A-620 compliance or a specific class is a customer requirement, put that on the print. Do not assume the shop will add those because the industry “usually does.”

We would rather quote the test you actually need than surprise you after a first-article build.

Commercial facts people forget

These change the number more than another 50 mm of cable:

• Prototype quantity versus the first production release
• Annual volume, even a range
• Target date, and whether that date is a hope or a line-down date
• Ship-to location, because packaging, freight, and delivery requirements can vary by destination
• Labeling and bagging if your receiving team is picky
• Whether this is a one-off or a program that should stay on the same revision through pilot

No fixed MOQ on our side does not mean a 2-piece build costs like a 2,000-piece build. Tooling, cut lists, and setup show up at the low end. That is normal. Put the volume on the RFQ so the quote is for the life you actually want, not a guess.

What we do with the pack

Once the files are readable, engineering reviews them the way a build would happen: can we source the parts, can we hold the lengths, where will the print fight the process. That is the DFM pass. Sometimes it is “good to build.” Sometimes it is two or three flags, like a bend radius that will not survive the backshell, or a connector with a 20+ week lead time.

You want those flags before you lock a PO, not after the form board is cut.

If you already have a failed first article from another vendor, send the failure note. It is more useful than another marketing paragraph about quality.

A pack we can quote without a meeting

That is enough to start. If something is missing, we will ask for that one thing instead of stalling the whole RFQ.

Upload what you have on the Request a Quote page at vezewire.us/rfq, or email the pack to mp@vezewire.com. If the drawing is ugly, send it anyway. Ugly and complete beats clean and empty.