Does every grenade transport case acceptance run a drop test?

Bulk delivery draws 3 pieces per lot and all nine drops must pass. Single-piece replenishment may substitute pressure decay plus wall thickness.

Does AQL 1.5 mean 1.5% defects are allowed?

No. AQL is the acceptance quality limit of the plan, not a permitted defect rate.

Can cosmetic defects be relaxed?

They can be negotiated, but a sink mark deeper than 0.2 mm on the sealing face is already major.

The seal passes but a latch feels loose. Acceptable?

No. A latch below 600 N is a major defect, and a 50 N synchronism gap opens first under vibration.

Why can reworked grenade transport cases not go straight to stock?

Rework changes assembly stress and hardware fit, so 160 samples across every rework tote confirm the defect has not simply moved.

Grenade Transport Case Acceptance Standards: Items and Decisions

Quick answer: Acceptance of a grenade transport case runs on three defect classes: critical items take zero acceptance, major items are sampled at AQL 1.5, minor items at AQL 4.0. A 500-piece lot draws 80 samples, and one critical defect sends the whole lot back.

Lot formation and sampling for a grenade transport case
Dimensional and visual inspection items
Seal and hardware performance judgement
Drop, stacking and thermal cycling verification
Decision rules and nonconforming disposition
FAQ

1. Lot formation and sampling for a grenade transport case

Inspection starts with lot formation, because a badly drawn lot makes every later number meaningless. A lot must share one mould number, one colour, one material batch and one press, produced in one continuous run, capped at 500 pieces.

A 500-piece lot maps to sample code J, which means 80 samples at general inspection level II. Critical defects, those breaking the seal or load path, run at AQL 0.065 with zero acceptance. Major defects sit at AQL 1.5 and minor cosmetic ones at 4.0.

Class	Typical items	AQL	Ac/Re at 80 samples	Disposition
Critical	Through crack, wall below limit, seal failure	0.065	0 / 1	Lot rejected
Major	Oversize, low latch force, hinge crack	1.5	3 / 4	100% sort or rework
Minor	Sink marks, flow lines, colour shift	4.0	7 / 8	Concession or sort

2. Dimensional and visual inspection items

Only drawing-critical dimensions are measured: outer size 620×420×230 mm at ±1.2 mm, wall 3.8 mm at ±0.15 mm, and rim flatness 0.6 mm. Any one out of tolerance is a major defect, since size drives stacking, wall drives load capacity, and flatness decides whether the gasket loads evenly.

Outer size is measured after four hours in a 23±2 °C room, because a fresh grenade transport case still shrinks. Wall is read at 10 points with an ultrasonic gauge, four of them in the corner radii. Sink marks deeper than 0.2 mm on the sealing face are promoted to major.

3. Seal and hardware performance judgement

Seal performance is judged by pressure decay, never by bubble testing. The cavity is charged to 15 kPa, held 30 seconds, then timed for 60 seconds; a decay above 0.6 kPa fails.

Latches need at least 600 N of holding force each, with no more than 50 N of difference between them. Hinges are cycled 5000 times and the grenade transport case must still pass the decay test. Screw torque is 1.2 N·m, verified on 5 samples.

Item	Test condition	Decision line	Class
Seal	15 kPa charge, 60-second hold	Decay at or below 0.6 kPa	Critical
Latch force	Pull along opening direction	At least 600 N	Major
Latch synchronism	Both paper strips pulled together	Difference at or below 50 N	Major
Hinge life	5000 cycles, then retest	No crack, decay still passes	Major

4. Drop, stacking and thermal cycling verification

Drop testing uses the harshest attitudes: one bottom face, four edges and four corners, nine drops from 1.5 m onto concrete. After each drop a grenade transport case must show no through crack, latches operable with one hand, and a passing decay test.

Stacking reproduces warehouse storage, not transport: three high with 600 kg on top for 24 hours, then permanent set within 2 mm after one hour of recovery, tested at 40 °C. Thermal cycling runs three cycles of -25 °C and 55 °C, four hours each, before latches and rim are re-checked.

5. Decision rules and nonconforming disposition

The order cannot be reversed: critical first, then major, then minor. One critical defect rejects the lot without tightened sampling. Major defects at the acceptance number mean 100% sorting or rework and resubmission; minor ones may pass by concession with the scope stated.

Resubmitted lots are sampled at 160 pieces, covering every tote that held reworked parts; a lot failing again is returned.

Outcome	Trigger	Disposition	Re-inspection
Accept	All classes within Ac	Release with report	None
Sort	Major class reaches Re	Inspect every piece	160 samples
Rework	Size or hardware repairable	Replace hardware or correct size	160 samples
Reject	One critical defect	Return lot, no conformity declaration	Not offered

Conclusion

Acceptance of a grenade transport case comes down to three habits: class the defects, fix the decision lines, order the dispositions. AQL with Ac/Re decides release, and 15 kPa decay with 600 N latch force decides whether the evidence suffices. Write those numbers into the procedure, and grenade transport case quality stops depending on impressions.

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.