How to write a CNC RFQ a shop can actually quote

We read EDC RFQs all day. The difference between one that gets a real number back in a day and one that bounces around for a week is almost never the part. It is the brief.

A shop that has to guess will do one of two things: ask you a list of questions, which costs you days, or quote defensively, which costs you money. Both are avoidable.

The eight lines

1. Material and grade. Not “titanium” — “Ti-6Al-4V, Grade 5”. Not “aluminium” — “6061-T6”. The grade changes the cycle time, the tooling and the finish. Leaving it open means the shop either quotes the cheapest or asks.

2. Quantity, and whether it repeats. “50 pieces” and “50 pieces every quarter” are different jobs. The second justifies better workholding, which makes every subsequent run cheaper. Say if you expect to reorder.

3. Finish, with colour. “Bead-blast” is half an answer. “Bead-blast, then Type II anodize, bronze, batch must match” is a full one. If you want a sample before production, say so here rather than after the quote.

4. The dimensions that matter. Three or four, usually. The screw pattern, the thickness at the pivot, the fit into the frame. Everything else goes to the general tolerance block. Calling out tight tolerance on all forty dimensions is the single most expensive habit in EDC RFQs.

5. The deadline you are working back from. Not “ASAP”. “Units in hand by 12 November for a 1 December drop” lets a shop tell you honestly whether it fits, and lets us route you to one whose schedule actually has room.

6. Quantity of prototypes before production. Most EDC projects want one to five first articles. Say it up front so it is priced into the same quote rather than raised later as a change.

7. Whether you need certs. Mill certs traceable to the heat lot, a dimensional report, a material declaration for a customer. All cheap if planned, all annoying if requested after the parts are cut.

8. NDA or not. If you want one, ask before you send the file, not after.

What to attach

STEP is the format that removes ambiguity — it carries the solid model, so nobody is interpreting a 2D view. Send a dimensioned PDF alongside it showing which dimensions are critical and where the datum is. See which CAD file to send for what each format does and does not carry.

If all you have is a sketch and a reference photo, send that. It is a normal starting point for a first EDC project and it is better than waiting three weeks to produce a model that turns out to be unmanufacturable.

What a good quote back looks like

Itemised: material, setup, machining, finish, packing, freight. A single lump sum tells you nothing about which line to negotiate. When setup is sixty percent of a small-batch number, the useful conversation is not “can you discount” but “what does 60 pieces cost instead of 25”.

It should also tell you what the shop changed or questioned. A quote that comes back with no comments on a first-time part usually means nobody read it properly.

The habit that saves the most money

Write the RFQ before you finish the CAD. Half the expensive features in an EDC part — the 1 mm internal radius, the pocket that needs a third setup, the tolerance nobody needed — are still cheap to change at that point. Send what you have and we will tell you what to change while changing it is free.

What not to put in an RFQ

“Best price.” Every shop already knows you want a good price. What this phrase actually communicates is that price is your only criterion, which invites a quote that hits the number by cutting something you did not want cut.

“Similar to this photo.” A photograph is not a specification. It is useful as supporting context alongside a model; it is useless as the only input.

A tolerance block copied from an aerospace template. We see drawings where a decorative chamfer carries a positional tolerance that came with the CAD template. The shop has to price it, because it is on the drawing and the drawing is the contract.

Forty dimensions when four matter. Covered in tolerances and fits, and worth repeating because it is the most expensive habit in EDC drawings.

“Let me know if you have questions.” You will get questions, and each round costs a day. The eight lines above are an attempt to pre-empt them.

Quantity breaks worth asking for

Ask for pricing at three quantities, not one. Something like 25 / 50 / 100.

This costs the shop almost nothing extra to produce and it tells you where the setup cost stops dominating. Frequently the answer surprises people: the jump from 25 to 50 adds far less than doubling, because you are buying more machining time against the same fixed setup. That is decision-relevant information you cannot get from a single number.

Ask for the price of an additional prototype separately too, because a spare first article is often worth having and it is cheap when it runs alongside the original.

Packing and freight belong in the RFQ

Two things that get bolted on afterwards and should not:

Packing. Individual bags, interleaving for stacked flat parts, anti-tarnish paper for copper alloys, foam for finished cosmetic surfaces. Every one of these is cheap when planned and irritating when requested after the parts are boxed. A finished scale with a rub mark from its neighbour has failed inspection just as completely as one that is out of tolerance.

Incoterm. EXW and FOB are different numbers and different responsibilities. Say which you want quoted. If you have a freight forwarder, name it; if you do not, ask the shop to quote air freight so you have a landed cost rather than a factory-gate cost.

Revision control

Put a revision letter on the drawing and change it when anything changes, including something you consider trivial.

The most common cause of a batch scrapped for the wrong reason is a shop working from rev B while the buyer is thinking about rev C. Name your files with the revision. Confirm in writing which revision a quote refers to.

A template you can copy

Part: [name], rev [X] Material: [grade and temper, or “or equivalent”] Quantity: [n], pricing also at [n1] and [n2]. [Repeating quarterly / one-off] Finish: [process, colour, batch match required yes/no, sample before production yes/no] Critical dimensions: marked C on the attached PDF. All others per ISO 2768-m Prototypes: [n] first articles before production, with dimensional report Certs: [mill certs / dimensional report / none] Deadline: in hand by [date] for a [date] launch NDA: [required before file review / not required] Incoterm: [EXW / FOB], packing [spec] Attached: STEP, dimensioned PDF, [DXF]

The RFQ is one step of the route from drawing to delivered batch, set out in our guide to custom EDC manufacturing.

FAQ

How long should an RFQ take me to write? Twenty minutes for a part you have already designed. The template above is most of it. That twenty minutes typically saves three to five days of back-and-forth.

Should I tell the shop my target price? Yes, if you have a real one. It lets a shop tell you honestly whether the design can reach it, and suggest what to change if it cannot. It does not cause the quote to rise to meet it — any shop where it would is a shop to avoid.

Should I send the RFQ to five shops at once? That is what a sourcing desk does on your behalf. Doing it yourself works too, but five separate technical conversations take five times the effort and you still have to normalise five quotes with different assumptions.

What if I do not have CAD yet? Send a sketch with the key dimensions and a reference photo. It is a normal starting point and it is far better than waiting a month to produce a model that turns out to be unmanufacturable. See design for CNC.

How fast should a quote come back? For a part with a complete brief, one to two working days. Longer usually means the shop is waiting on a material price or a sub-supplier quote, which it should tell you.