Does a Plastic Tool Box, Portable always need 80 samples?

Answer: No. Eighty fits a lot of 800 at level II; smaller lots need fewer pieces, but the AQL mapping stays fixed.

Where does the delta E 1.5 limit come from?

Answer: Measured against the signed sample under D65 light: above 1.5 it shows side by side, above 3 when a unit stands alone.

Why drop test with 18 kg of ballast?

Answer: An empty drop measures shell stiffness only; ballast near the working load shows how the latches behave.

How much latch force may be lost after cycling?

Answer: Thirty percent at most. Below 70 percent of the initial figure the claw root has yielded and the latch will open in transit.

Can a concession lot be shipped for export?

Answer: Not normally: export orders expect every item to pass, so a concession needs written customer approval.

Plastic Tool Box, Portable: Inspection Items and Verdicts

Quick answer: Acceptance of a Plastic Tool Box, Portable runs in three steps: fix the sampling plan, fix a numeric limit for each item, then decide what happens to a failed lot. Eighty units cover latch, handle, dimension and appearance, and any major defect above Ac fails the batch.

Start With a Sampling Plan
Appearance and Dimension Limits
Latch, Handle and Hinge Cycling
Drop, Stack and Temperature
Batch Verdict and Nonconformance
FAQ

1. Start With a Sampling Plan

Acceptance of a Plastic Tool Box, Portable starts with a plan, not full inspection: 800 units at inspection level II gives a sample of 80, with AQL 2.5 for major defects, Ac 5 and Re 6, and AQL 4.0 for minor ones, Ac 7 and Re 8. Without it, two inspectors judge a delivery differently.

Lots split before sampling: one mould, one shift, one colour; a resin or press change starts a new lot. Otherwise the sample averages two machines.

Defect class	Typical items	AQL	Verdict at 80 pieces
Major	latch springs open, handle crack, hinge break	2.5	Ac 5 / Re 6
Minor	sink, colour shift, flash, parting offset	4.0	Ac 7 / Re 8

Dimension gets its own sample, since it does not fit defect counting: one oversize part in five doubles the sample to 13, a second failure sends the lot to full inspection.

2. Appearance and Dimension Limits

Appearance limits are numbers, not adjectives: colour shift within delta E 1.5 of the signed sample under D65 light, sink under 0.15 mm so a fingernail does not catch, flash under 0.2 mm, parting offset under 0.3 mm. Written this way, an argument about looks becomes a measurement.

Plastic Tool Box, Portable: six layers of pale grey cases on a timber pallet in a workshop, orange racking and blue bins behind

Dimensions come off a caliper with 0.02 mm resolution: cavity long side within plus or minus 1.0 mm, envelope within 1.2 mm, stack gap within 1.5 mm between units of one lot, measured 10 mm below the rim and 15 mm above the base corner.

Out-of-tolerance parts that still assemble need a concession with written scope and expiry. Rework covers flash and parting lines; sink and colour shift cannot be reworked.

3. Latch, Handle and Hinge Cycling

The latch runs 8000 cycles and must then hold 70 percent of its initial force. The handle takes 250 N for 5000 cycles and may set 2 mm or less an hour after release. The living hinge runs 15,000 cycles without crack or whitening. Keep that order, or a racked body spoils the verdict.

Test	Condition	Cycles or time	Verdict
Latch	room temperature, empty	8000 cycles	holding force at least 70 percent
Handle	250 N	5000 cycles	set 2 mm or less
Metal parts	neutral salt spray	48 hours	rating 9 or better, no red rust

Metal parts get the salt spray, as latch springs and hinge pins are the only steel here; polymer parts take temperature cycling instead.

4. Drop, Stack and Temperature

Drop tests run from 1.2 m onto six faces, three edges and one corner, with an 18 kg sand bag inside. Two criteria only: the latch stays closed and the body shows no through crack. Paint loss at a corner is acceptable; say so, or a scuff stalls a delivery.

Plastic Tool Box, Portable: a tiled factory wall with a gold signboard, red fire hydrant valves and an open box truck loaded with white sacks

Stacking applies 60 kg for 48 hours: the bottom unit may deform 2.0 mm and must recover 80 percent within an hour. Temperature cycling holds -25°C and 60°C for four hours each, three cycles, with a drop within two hours of removal. A latch that snaps brittle in the cold voids every earlier result.

5. Batch Verdict and Nonconformance

Verdicts are item by item: major defects above Ac fail the lot, and strong minor results cannot offset them. Dimensions and cycling stand on their own lines. A weighted score looks tidy and is the first thing overturned.

Nonconformance has three routes: full screening with records, rework limited to flash and parting lines, or rejection with a defect code. Concessions need written scope and expiry, never above 15 kg per unit.

Conclusion

An acceptance standard for a Plastic Tool Box, Portable is a set of measurable lines, not an opinion: a sampling plan, numeric limits, cycle counts for life, drop and stack for the boundary, and item by item judgement. Write one item as an adjective and the standard fails in practice. With the lines fixed, a Plastic Tool Box, Portable is accepted twice with the same result.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.