Who should set hand tools case standards?

A: The user sets the limits, the supplier holds the process; a limit written by the supplier tends to match what it already achieves.

Can sampling cover appearance only, with size left to the first article?

A: No. A first article proves the mould started well, not that the lot is stable. Dimensions drift with cooling, so measure five per lot.

Does AQL 1.0 permit one percent defective?

A: No. AQL is an acceptance limit, not a defect allowance. At 501 to 1200 pieces the sample is 80 with acceptance number 2, so the third failure rejects the lot.

How many drops are enough?

A: Ten, over six faces, three edges and one corner. Fewer misses the corners, the thinnest part of the shell.

Why re-inspect stock older than six months?

A: Additives migrate and latch toughness falls. Check latch force and a corner drop; passing both, the goods can ship.

Hand Tools Case Standards: Seven Checks and Their Limits

Quick answer: Hand tools case standards rest on seven testable items: appearance, dimensions, insert fit, latch force, drop, stacking and salt spray. Sample to GB/T 2828.1 level II with AQL 1.0 for major defects, 2.5 for minor, zero tolerance for critical. Written into the inspection sheet, the limits give the same verdict whoever repeats the check.

Hand tools case standards: the seven incoming checks
Sampling plans and acceptance numbers
Defect classes and how they are judged
Six type tests before shipment
Records, traceability and re-inspection
FAQ

1. Hand tools case standards: the seven incoming checks

Incoming inspection decides whether a lot can be received.

Check	Gauge or rig	Limit
Appearance, colour	Colour chip, 10× loupe	ΔE within 1.5, flash under 0.3 mm
Envelope size	Vernier, granite plate	±2 mm, diagonal within 3 mm
Insert fit	Feeler gauge, sample tool	0.5 to 2 mm gap, no rattle
Latch force	Pull gauge, hook fixture	Holding 120 N, opening 45 to 85 N
Drop	Drop rig, concrete base	1.2 m loaded, no crack, latch holds
Stacking	Stack frame, weights	400 kg for 24 h, set within 3 mm
Salt spray	Neutral chamber	48 h, rust under 5 percent

The last three need equipment and run as type checks: first article, material change, stoppage over thirty days. Insert fit is usually written as "no visible defect", yet no eye sees the 0.3 mm offset that jams pliers.

2. Sampling plans and acceptance numbers

Sample to GB/T 2828.1, normal inspection, single sampling, level II: lot size gives the letter, the letter the sample size, AQL the acceptance numbers.

Lot size	Code	Sample	AQL 1.0	AQL 2.5
151 to 280	G	32	1 / 2	2 / 3
281 to 500	H	50	1 / 2	3 / 4
501 to 1200	J	80	2 / 3	5 / 6
1201 to 3200	K	125	3 / 4	7 / 8

Judge major and minor separately; five accepted lots move to reduced inspection, one rejection to tightened.

3. Defect classes and how they are judged

Classification splits "reject" into three actions: critical rejects the lot, major is judged at AQL 1.0, minor at 2.5 can be sorted and resubmitted.

Hand tools case in red lined up closed on a steel shelf, one unit open on a bench with pliers and wrenches in black foam

Keep the critical list short: a latch that releases itself when closed, a handle that breaks under load, an insert that lifts to expose metal, a sharp edge within reach. Any one is a design problem, not a sampling issue. Where they blur, ask whether a tool can fall out or a hand tools case can gap in transit.

4. Six type tests before shipment

Type tests judge the model rather than the lot: six of them cover transport, storage and climate stress, and the report travels with the goods.

Test	Parameter	Pass criterion
Drop	1.2 m loaded, ten drops	No crack, latch holds, insert seated
Stacking	400 kg, 24 h	Set within 3 mm
Salt spray	Neutral, 48 h	Rust under 5 percent
Latch life	3000 cycles	Holding force within −20 percent
Vibration	10 to 55 Hz, 2 h	No loosening, no rattle
Thermal	−20 and 60 °C, three cycles	No crack, no permanent set

Draw samples at random: units built for the test pass while production does not.

5. Records, traceability and re-inspection

Records narrow the search after a failure. An eight-digit lot code — date, machine, shift, such as 260318A2 — on the base and on the insert back means one lot when both match, mixed production when they do not. A cavity number decides whether a lot or one position is quarantined.

Keep two samples per lot for twelve months, records for three years. Re-inspection triggers: the same complaint twice, a new supplier, stock over six months. The third is forgotten most often: plasticiser migration makes latches brittle, so a hand tools case cracks on opening with no production fault.

Conclusion

A standard does not keep bad units out so much as tell the supplier where the door is: seven items say what to measure, the plan how much, the classes how to judge. In the contract, they give hand tools case quality a floor that holds across shifts.

This article covers container-side specifications and design implications only, not the handling, loading or use of the contents.