Most sourcing problems start before the first order: the buyer compares four suppliers who are actually four different kinds of business, and treats their prices as if they were comparable. This checklist is about asking the right question of the right channel.
Four channels, four different businesses
A moulder sells capability. It owns tools, mixes or buys compound, and can make a size that does not exist yet. Its price is built around setup and run time, so small mixed orders are awkward for it and custom work is natural.
A trading company sells availability. It holds no tools of its own and quotes from a network of factories. On a standard size it can be fast and flexible about quantity; on a technical question it forwards the message and waits.
A stockist sells speed. It buys in volume and ships from a shelf, which means the size you want is either there or it is not, and the price includes someone else holding the inventory for you.
A marketplace sells visibility. You see many prices at once; what you do not see is who actually moulds the part, whether the photographs are of the seller's own production, or what happens when a batch is wrong.
None of these is the right answer in general. The right question is which one can answer your specific requirement — a standard size in three days, or a new bore in a new colour.
In stock usually means three things at once
A sleeve is only genuinely available if the tool exists, the compound is on the shelf, and the colour is scheduled. Suppliers often say in stock when only the first two are true, and the third turns a three-day promise into a three-week one.
So ask a narrower question: which colour is on the shelf today, and how many pieces of this exact size. Vague stock answers are a reliable predictor of vague delivery dates.
Five questions that get real answers
- Which terminal series and wire range does this sleeve fit? A supplier who sells the part should answer without checking.
- Is the tool yours or the factory's, and can I have that in writing? This decides whether you can move supplier later.
- What is the wall thickness and its tolerance, not just the bore? Bore alone does not tell you whether the sleeve will split on assembly.
- For a custom colour, is there a separate minimum and a separate lead time? Colour is the most common hidden constraint.
- If the first batch is out of tolerance, what happens? The answer tells you more about the supplier than any certificate.
How to compare quotations without being misled
Unit price is the least comparable number in the file. Two quotes for the same part can differ because one includes tooling amortised into the piece price and the other charges it once, because one quotes ex-works and the other delivered, or because one is based on a compound grade the other would not use at that price.
Line up five things before comparing: tooling as a separate one-off line, packing and carton quantity, incoterm and who pays freight, currency and validity period, and the payment split. A quote that does not state validity is not a commitment — compound prices move.
Prepare these three things before you ask anyone
First, the mating part: a terminal sample, or the series name plus wire range. Second, the annual volume and the first order size, because they are different questions and they produce different prices. Third, the market the part goes into, since that decides which material declarations you will eventually be asked for.
With those three, a quotation takes a day. Without them, every supplier guesses, and the guesses are not comparable.
Sample, trial, and production are three different requests
A sample request is answered from stock or from a short hand run. A trial order is a real production run at a small quantity. A production order is the same run at scale, with packing and scheduling attached. Suppliers often quote one of the three when you asked for another, and the numbers look comparable until delivery.
State which one you want in the first sentence of the enquiry. If you ask for a sample and receive a quotation with a carton price and a lead time, you are being quoted for production, and the sample you actually need has not been discussed.
Red flags worth taking seriously
None of these is fatal on its own, and one of them on a first enquiry is common. Three together on the same quotation is a pattern, and the pattern is what you should walk away from rather than any single item.
- A price that is far below the others with no explanation of what was left out.
- Photographs that appear across several suppliers' pages.
- Refusal to name the material grade, only the word PVC or silicone.
- No tolerance stated on any dimension.
- Pressure to pay a large deposit before a sample is approved.
Frequently asked questions
Is a trading company always more expensive than a factory?
No. On a small mixed order a trader's consolidated freight and held stock can beat a factory's setup cost. Compare total landed cost at your order size, not unit price at someone else's.
Should I buy from the factory if I only need a few thousand pieces?
It depends on whether the size is standard. If it is, a stockist is usually faster and cheaper at that quantity. If it is a new bore or a new colour, only the factory can make it.
What should I have before paying a deposit?
A sample or photograph of the exact cavity and colour, plus written acceptance criteria for the dimensions you care about. Paying before either exists means the standard is decided after the money moves.
Do I need a drawing for a standard sleeve?
No. For an existing size the terminal series and wire range identify the part. A drawing becomes necessary as soon as a dimension is custom or the tolerance matters to your assembly.
How long should a quotation stay valid?
Ask explicitly and get it in writing. Compound prices move with the resin market, so an open-ended quote is either generous or about to be revised.