First Sleeve Order: How to Inspect It and How to Pay

An acceptance criterion without a sampling plan is only a wish

The plan answers two questions at once: how many pieces are measured, and how many defects still count as a pass. Getting one without the other is how disagreements start — a buyer writes "no splits" and a supplier ships whatever the mould produced.

ISO 2859-1 covers this. The combination used most often in this product class is general inspection level II, normal severity, single sampling, with AQL 2.5 for major defects and 4.0 for minor ones. For a moulded sleeve the numbers work out like this:

Two things to understand before that table goes into an order

The sample does not scale with the lot. A 500,000-piece order is inspected at 500 pieces, not at 10% of the shipment. What the plan buys you is a decision rule with a known error rate, not a proportion of the goods verified. If you need a proportion, you are buying sorting, which is a different service at a different price.

The numbers are a ceiling, not a target. Accepting a lot at AQL 2.5 means the plan will still pass shipments running near that defect rate a good share of the time. So if a defect would stop your assembly line — a split wall, a bore that will not seat, a flash ring inside the bore — do not give it an AQL at all. List it as a critical defect, inspect it separately at c = 0, and state in writing what happens to the lot if one piece fails.

Draw the sample across the cartons rather than off the top layer. Two hundred pieces pulled from the first box test one moulding run and tell you nothing about the other nineteen, which is usually where the tool was running hot or the operator had changed.

Four payment structures, and what each one actually protects

Whichever you choose, three terms belong in the quotation rather than in the chat thread: the acceptance criteria the balance depends on, the number of days you have to raise a claim after arrival, and who pays return freight on a rejected lot. A supplier who will not state those three in writing is telling you in advance how the dispute will go.

• 30/70 by T/T — a 30% deposit with the balance against a copy of the bill of lading. The supplier is financed through production and the buyer holds the balance until the goods are on the water, but the balance is released against a document, not against an inspection result.
• 30/70 with the balance after inspection — the same deposit, with the 70% released only once the pre-shipment report is signed. This is the version to ask for on a first order. It costs the supplier working capital, which is precisely why it carries information.
• Letter of credit at sight — bank-intermediated and governed by UCP 600. The bank checks documents, not parts, so it protects you against non-shipment and document fraud rather than against a bad moulding. As a rough rule the fee is hard to justify below roughly USD 30,000 of order value.
• Platform escrow — Trade Assurance and its equivalents hold the money until you confirm receipt. Convenient on small orders, but the dispute window closes, and tooling costs usually sit outside the cover.

Ten checks that decide a pre-shipment inspection

A remote audit happens before you order; a pre-shipment inspection happens after production and before the balance is paid, and it is the last point at which a problem is still cheap. These ten cover the failure modes that actually occur on a moulded sleeve:

• Quantity and carton count — counted against the packing list before any carton is opened. Short shipment is more common than bad parts.
• Part identification — carton label, inner bag label and the part itself must agree on part number, size and lot. A mismatch here invalidates every other check on the list.
• Bore diameter at both ends — the gate end and the open end measured separately. An oval bore passes a single measurement and leaks on the line.
• Wall thickness at four points — with a gauge, not a caliper jaw across the outside diameter. Uneven wall is the defect that produces splits in service.
• Overall length — against the drawing, on ten pieces, so you see the spread rather than one number.
• Flash at the gate and the parting line — cosmetic flash is acceptable; flash inside the bore is not, because it changes the clearance you designed for.
• Colour against the approved reference — under daylight, next to the signed sample. Photographs taken under factory lighting have caused more colour disputes than any amount of colour drift.
• Hardness, where the drawing specifies it — Shore A on a flat section, not on a curved wall, where the durometer reads low.
• A seating trial — fifteen to twenty pieces fitted by hand onto the terminal you actually use, recording how many needed force and how many sat loose.
• Packing and labelling to the agreed standard — bag quantity, carton weight, shipping marks, and whether the carton survives a stack of three. This is where sea freight damage begins, not in transit.

Record measurements, not verdicts

A report that says "passed" cannot be argued with afterwards, which is convenient for exactly one side. A report that lists the ten values can be argued with, and that is what you are paying for. Ask for the numbers, and ask which instrument produced them.

Book the inspection before production ends, not after. Once the goods are packed and the container is booked, an inspection that finds a problem costs you the freight and the schedule as well as the parts — and the supplier knows that as well as you do.