The cot rail gap was 60 mm: inside the standard, outside the order, and no compliant cot could pass the buyer's own test
Illustrative example This case is written from the patterns we see in furniture export orders, and the figures are representative rather than from a specific client file. It shows how a check works and what it finds. We will replace it with a real, anonymised case as soon as we can publish one with the buyer's permission.
The situation
A European online retailer of children's furniture ordered 800 convertible cots from a factory in Foshan. Each cot was a solid beech frame for a 70 × 140 cm mattress, with a mattress support that adjusted between three heights, supplied flat-packed with the mattress alongside. The order was worth $84,000. Thirty per cent was paid as a deposit, and the balance of $58,800 fell due when the factory asked for the booking.
The buyer's safety appendix ran to eleven lines, and most of them were sensible. Surface coatings to comply with EN 71-3. No small parts detachable by a 25 N pull. The cot stable on a 10° incline. The side to take a 750 N vertical load. All of that was checkable, and all of it was checkable against a document the factory already had.
Two lines were not. The appendix said the clear gap between the vertical elements shall not exceed 45 mm, and it said this would be verified by inserting a 40 mm test rod, which was not to pass. The factory's engineering team read both lines and did what any competent supplier would do, which was to point out that the two of them do not describe the same requirement.
The buyer's quality manager did not have an answer, so the order went ahead with the gap left ambiguous in practice. The factory built a 60 mm nominal gap and ran the buyer's own rod on the first twenty assembled cots. Twenty failures, because a 60 mm gap swallows a 40 mm rod. The factory escalated with the standard in hand, the buyer held the balance, and an independent inspection was booked before the money moved.
The result was that the goods were conforming to the standard on the characteristic the order complained about, and non-conforming on a characteristic the order never mentioned.
This is an illustrative example drawn from a recurring pattern in children's furniture orders, where a safety characteristic is reduced to a single number in the buyer's own checklist and the number turns out to be the wrong end of a range. The figures are representative of the category rather than taken from a named customer file.
Where to go next
→ why an inspection happens before the balance is paid rather than after
The number in the order, and the number in the standard
EN 716-1 does not specify a maximum gap between the vertical elements of a cot. It specifies a range: not less than 45 mm and not more than 65 mm. The lower bound exists because a gap below 45 mm will admit a child's finger or limb and hold it there. The upper bound exists because a gap above 65 mm will admit a child's head and not the shoulders behind it. Both ends of that range are hazards, and the whole logic of the requirement is that a gap has to sit inside it rather than beneath it.
So the buyer's 45 mm maximum, read as a maximum, was the lower bound of the range written as though it were the upper one. That is an easy mistake to make. The 45 mm is the number a reader remembers, because it is the number at the start of the sentence, and a checklist column headed 'maximum' is precisely where a number like that ends up.
It is worth being exact about what the factory did. The 60 mm gap is inside the EN 716-1 range, and the factory verified it with the standard's own tapered plug gauges: the 45 mm plug passed and the 65 mm plug was blocked, at every position measured. On the characteristic the order complained about, the goods were conforming to the standard and non-conforming to the purchase order. Those are two different findings, and the report kept them apart.
The 40 mm rod is where the order breaks down on its own terms, and it does so twice. EN 716-1 requires the 45 mm plug to pass when it is pushed with the specified force, which means a compliant gap is above 45 mm and not at it. The buyer had specified a rod of 40 mm that must not pass. No cot that satisfies EN 716-1 can pass that check, because the smallest gap the standard permits is already wider than the rod. The acceptance test was incapable of being passed by a compliant product.
And the rod and the stated limit do not test each other either. A 40 mm rod that must not pass bounds the gap below 40 mm. A 45 mm maximum bounds it at 45 mm. A gap of 42 mm fails the rod check and satisfies the limit; a gap of 38 mm passes the rod check and fails the limit. The two lines describe two different gaps, and neither of them is the standard's gap.
The trap is in the obvious remedy. Tightening the specification is instinct, and it is how a non-conformance gets closed without anyone examining what it produces. Instruct the factory to bring the gap down to 44 mm so that the 40 mm rod stops, and the cot now sits below the standard's lower bound, where a child can get a hand into the gap and lose it. The buyer's stricter specification was not a safer one. It was a specification for a product that cannot be made safely.
Where to go next
How the gap is measured, and why a photograph cannot measure it
The gap was measured with the standard's tapered plug gauges, not with a rule and not with an impression. Two gauges: a 45 mm plug that has to pass when pushed with the specified force, and a 65 mm plug that has to be stopped by it. Anything that passes the first and is blocked by the second is a compliant gap. A rule produces one number in one place, and a compliant gap is a relationship between two numbers, so a rule cannot confirm it.
The measurement was taken at the narrowest point of every aperture, in both the vertical and the horizontal direction, at both ends of each rail as well as in the middle, with the cot fully assembled and with the mattress in place. A gap that is even in the middle of a rail is not even at the end, and the ends are where the spindles sit closest together and where a child's head goes first.
The gauges were used again with the cot loaded, because the standard requires the distance to be maintained when the members are loaded and not only when they are at rest. A child leaning on the side closes a gap by a millimetre or two, and the reading taken at rest is not the reading that governs.
One measurement was taken that is not a gap measurement at all: how deeply each spindle is let into the rail it is set into. It came out at 11 to 14 mm across the sample, and four spindles could be rotated by hand in their sockets. That is a workmanship finding on a joint, it is a different non-conformity from the one the order raised, and the report gave it its own line rather than folding it into the gap discussion.
The third column of the table below is the finding. The fourth column is why it matters. Reporting '60 mm' on its own would have started an argument about the order. Reporting that the 45 mm plug passed and the 65 mm plug was blocked at every position ended it.
| Check | Method | Result on the sampled cots | What it establishes |
|---|---|---|---|
| Clear gap between vertical elements, narrowest point | 45 mm and 65 mm tapered plug gauges, both directions, both ends of each rail | 58–62 mm; 45 mm plug passes, 65 mm plug blocked | Conforming to EN 716-1; the purchase order's 45 mm maximum is not met |
| Same gap with the cot loaded | Gauges reapplied under the standard's loading condition | Gaps closed 1–2 mm at the loaded member, none exceeding 65 mm | Conforming when loaded, which is how the standard defines the limit |
| The buyer's own acceptance check | 40 mm test rod, required not to pass | Rod passed at every measured position | Void: the rod bounds the gap below 40 mm and the order caps it at 45 mm, and neither is the standard's gap |
| Spindle engagement depth in the rail | Measured at the joint, 10 positions per cot | 11–14 mm; 4 spindles rotatable by hand in their sockets | A second and separate non-conformity, on workmanship rather than design |
The third row is the one that changes the conversation. A gap of 60 mm is a fact. A gap of 60 mm measured against a check that no compliant product could ever pass is a fact about the check.
Where to go next
The number that was hiding in the mattress
The rail height failure took a different route and had nothing to do with the gap. The buyer's order specified the mattress size, 70 × 140 cm, and did not specify a thickness, because thickness is not a line that appears on a furniture schedule and nobody asks for it. Cot mattresses in this category run from 60 mm to 150 mm thick. Every one of those sizes is normal, every one of them is sold as the right mattress for the cot, and the order's silence covered the whole range.
EN 716-1 sets the rail height as the distance from the top of the cot side down to the mattress surface: not less than 600 mm with the mattress support at its lowest position, and not less than 300 mm at its highest. The reference plane is the mattress surface, not the platform the mattress rests on, and that distinction is the entire case. A thicker mattress raises the mattress surface, and a raised mattress surface sits closer to the top of the rail, so a thicker mattress reduces the rail height at both ends of the adjustment.
The frame gives 690 mm above the support platform at the lowest position and 390 mm at the highest. Set the mattress thickness against those numbers and the frame complies only while the mattress is 90 mm thick or thinner. The factory's own showroom sample had an 80 mm mattress in it and passed comfortably. The buyer's nominated mattress, the standard product at that size, was 120 mm.
So the frame was not altered between the showroom and the container. The mattress was. And the frame had no margin to give, because a design that only works with the thinnest mattress the market sells is a frame with a tolerance of about 10 mm across a 90 mm range of commercially normal input. The factory had built to a number it drew on the drawing, and the drawing was right about the frame and silent about the one component that decides the result.
This is the finding that cannot be seen by looking at the cot, and it is not unusual at all. The frame is checked bare, on the floor, with nothing in it. The mattress arrives separately, is put in by the customer, and changes the compliance of the product in the customer's own house. Every unit in the sample passed the factory's own check on the bare frame, and every unit in the container was non-conforming with the mattress the order had specified.
| Mattress in the cot | Rail height above the mattress surface, lowest position | Same at the highest position | Result against EN 716-1 |
|---|---|---|---|
| 80 mm, the factory's showroom sample | 610 mm | 310 mm | Conforming at both positions, with 10 mm of margin at the low position |
| 90 mm, the thickest mattress the frame tolerates | 600 mm | 300 mm | Conforming exactly, with no margin at all |
| 120 mm, the buyer's nominated mattress | 570 mm | 270 mm | 30 mm short at both positions |
| 150 mm, the thickest sold in this category | 540 mm | 240 mm | 60 mm short at both positions |
| Frame measured to the support platform, no mattress | 690 mm | 390 mm | Not the reference plane the standard uses |
The last row is the number most people measure, and it is the number that makes the frame look generous. It is a measurement of the frame rather than of the product. The standard does not use it, because the standard is about the child in the cot and not about the cot on its own.
Why safety dimensions are not sampled
The buyer's file also carried a sampling instruction, and this is where a report can do real damage if it is careless about it. The order said AQL 2.5 for general inspection. For a rail gap of 60 mm, an AQL of 2.5 means almost nothing. It means that in a sample of 32 units, a certain number of non-conforming units is acceptable. It is a statistical allowance for a characteristic whose risk is a scratch.
A rail gap is not that kind of characteristic, and neither is a rail height. These are safety characteristics, and a safety characteristic is judged on every unit or it is not judged. There is no acceptable proportion of cots whose vertical elements sit 65 mm apart. A sampling plan applied to a safety dimension describes a defect rate rather than accepting it, and a report that lets a safety finding travel through an AQL decision has misrepresented the standard it is working to.
So the gap and the height were measured on all 32 units of the sample, and spindle engagement was measured at 10 positions on each. The 320 cots already packed were the remaining question, and the report recommended opening a set of packed units to extend the check, because a gap does not change when a cot is packed and there was no basis for assuming the packed units differed from the ones standing on the floor.
Doing it that way produced a result that was uncomfortable for the buyer and useful to them. Every unit measured had a gap inside the EN 716-1 range, and every unit would have failed the buyer's 45 mm line. There was no sampling risk to characterise, no acceptance number to argue about, and no route to closing the finding by pointing at a plan.
What the report established, and what it did not
What the report established: that the clear gap at the narrowest point of every measured aperture was 58 to 62 mm across the 32 sampled cots; that the 45 mm tapered plug passed and the 65 mm tapered plug was blocked at every measured position, with and without load; that the cots therefore conform to EN 716-1 on that characteristic and do not conform to the purchase order's 45 mm maximum; that the order's 45 mm maximum and the standard's range have no compliant value in common; and that the rail height above the mattress surface was 570 mm at the lowest support position and 270 mm at the highest with the 120 mm mattress, against 600 mm and 300 mm required.
It also established that the same frame conforms with an 80 mm mattress, that the frame's tolerance across the commercially normal range of mattress thicknesses is about 10 mm, and that spindle engagement measured 11 to 14 mm with four spindles hand-rotatable in their sockets.
What it did not establish: why the buyer's checklist carried 45 mm as a maximum, where that number came from, or whether it had been written for this product category at all. It also did not establish whether any child had been harmed, which is not an inspection question and which the report did not speculate about.
What it could not establish: the condition of the 320 packed units, which had not been opened, and the effect of either finding on the seller's certification, which is a matter for the accredited laboratory that issued the test report and for the buyer's own compliance file. The report recorded the measurements, named the standard each one was measured against, and stopped there.
The conclusion it carried was not a rejection, and the reason is worth stating. On the gap, the goods conform to the standard and the order was defective, and no factory can be instructed to make a product that satisfies a specification with no compliant value. On the height, the goods do not conform to the standard, the fault sits in the frame's tolerance and in the order's silence about the mattress, and the remedy is a different frame and a nominated thickness rather than a different gap. Two findings of similar apparent size, pointing in opposite directions, and a report that merged them into one verdict would have been wrong in both directions.
Where to go next
→ what a report records when a lot passes and a lot fails
→ our beds scope, for cot and bed frame verification against your specification
What the specification should have said
Seven lines. None of them costs anything to write, and together they replace a single copied number with a checkable requirement and a correction to the buyer's own checklist, which is the document most likely to be reused on the next order and the next factory.
- **Quote the range, not a number.** The clear gap between vertical elements shall be not less than 45 mm and not more than 65 mm in accordance with EN 716-1, verified with the standard's 45 mm and 65 mm tapered plug gauges, the first passing and the second blocked. A single maximum on a characteristic the standard defines with two limits is not a specification, it is a guess, and it is more likely to be the wrong end of the range than the right one.
- **State the acceptance test as the pair of gauges, and nothing smaller.** The 45 mm plug shall pass when pushed with the force the standard specifies and the 65 mm plug shall be blocked, measured at the narrowest point of every aperture in both directions and at both ends of each rail, with the cot assembled and with the mattress in place, and repeated with the cot loaded. Any test rod smaller than 45 mm is void, because no compliant cot can fail it.
- **Make the mattress an input to the height check and not a furniture schedule line.** The cot shall be supplied with a mattress of 70 × 140 cm and a stated thickness, and the rail height shall be verified with that mattress in place at every mattress support position. Where the buyer nominates the mattress, the height check is done with the buyer's mattress and not with the factory's.
- **Give the height criteria with their reference plane.** Not less than 600 mm from the top of the cot side to the mattress surface at the lowest mattress support position, and not less than 300 mm at the highest, measured to the mattress surface. Measured to the support platform the same cot passes, and it is the mattress surface that the standard means.
- **Take the safety dimensions out of the AQL.** Gap, rail height above the mattress surface and spindle engagement depth shall be measured on every unit in the lot and the record shall travel with the order. Safety characteristics are not sampled, and no acceptance number applies to them.
- **Fix the first ten.** The first ten cots of the run, complete with the specified mattress, shall be presented for verification against the clauses above before the remaining 790 are built, and no unit shall be packed against an unverified first article.
- **Correct the checklist as well as the order.** Where a buyer's own safety checklist carries a single maximum for a characteristic that the governing standard defines as a range, the purchase order shall state the range and the checklist shall be amended in the same revision. The checklist is the document that travels to the next factory, and in this case it was the document that travelled wrong.
The point of all seven is not to catch the factory out. The factory built a cot that passes the European standard and told the buyer so, in writing, before the goods were finished. The gap finding and the height finding look like the same kind of problem, one with comfortable margin and one with none at all, and the only way to tell them apart was to measure the gap with the standard's own gauges and to measure the height with the mattress the order had actually bought.
Where to go next
→ our beds scope, for cot and bed frame verification against your specification
→ what a report records when a lot passes and a lot fails
→ how sampling works under ISO 2859-1
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