How many categories does a Tool Roll inspection cover?

Answer: Six, from sampling to packaging and marking. A 500-piece lot takes about six hours.

Why is a 2 mm slot error major?

Answer: The slot is functional. Two millimetres narrow and the tool will not enter; three wide and it slides, pushing the rolled diameter up 4 to 6 mm.

Where does the 600 N figure come from?

Answer: A loaded ten-slot Tool Roll weighs about 12 kg and the strap sees roughly 120 N, so 600 N is a safety factor of five.

Grey card grade or colour difference number?

Answer: The instrument, because two inspectors can differ by half a grade under the same lamp.

How is a reworked lot resampled?

Answer: At the original lot size and sample count, with nothing reduced, and flagged in the record.

Tool Roll Acceptance Standards: Items and Pass-Fail Rules

Quick answer: A Tool Roll is accepted batch by batch with numbered samples and fixed accept-reject limits. Appearance is judged at 1000 lux, dimensions after conditioning, strength by load, pull and cycles.

Sampling and Tool Roll Batch Definition
Appearance and Stitching Checks
Dimensions and Slot Tolerances
Strength and Durability Tests
Batch Judgement and Rework
FAQ

1. Sampling and Tool Roll Batch Definition

Batches are split before any sample is pulled: one fabric roll, one slot pattern and one sewing shift make one batch. Mix two fabrics and fifty samples describe nothing about the rest of the lot.

Sampling is adjusted counting at level II: 32 samples for 151 to 280 pieces, 50 for 281 to 500, 80 for 501 to 1200. Major defects run at AQL 2.5, minor at 4.0, and samples rest four hours at 20 °C and 65% relative humidity before measuring.

Lot size	Samples	Major accept	Major reject	Minor accept	Minor reject
151 to 280	32	2	3	5	6
281 to 500	50	3	4	7	8
501 to 1200	80	5	6	10	11

2. Appearance and Stitching Checks

Appearance is viewed at 1000 lux from 600 mm with both faces turned. A blemish above 3 mm is major, a skipped stitch under 1 mm is allowed twice per piece, and stitch density runs 28 to 32 per 100 mm.

Tool Roll: a yellow pegboard bay with stacked black cases on a green bench, two women seated at red stools, an air hose reel above

Seam allowance is 8 mm plus or minus 1 mm, with three backstitches and the tail buried within 5 mm at every start. Colour is graded on a grey card under D65 at grade 4 or better, then confirmed at a colour difference of 1.5.

3. Dimensions and Slot Tolerances

Dimensions are taken flat and unstretched: plus or minus 5 mm on body length, 1.5 mm on slot width, 3 mm on slot depth, 5 mm on strap length. Cloth tapes are excluded because they carry 2 mm of their own error.

Slot width is functional, so an error there is major. Two millimetres narrow and a 24 mm open-end wrench will not enter; three wide and it slides, adding 4 to 6 mm to the rolled diameter. A ten-slot roll loaded with 3 kg of ballast must hold 82 mm, plus or minus 4 mm.

4. Strength and Durability Tests

Hang 3 kg from one slot for 24 hours: sag may not exceed 2 mm and no seam may open. The full roll then hangs at 1.5 times load, about 18 kg, for 30 minutes.

Tool Roll: a steel-framed assembly bay with a blue sign reading assembly group one, workers along green benches, black plastic catches heaped in front

A 25 mm webbing sample is pulled at 100 mm per minute over a 150 mm gauge and must hold 600 N for 60 seconds, while buckles cycle 3000 times. Four cycles at minus 20 °C and 60 °C must leave the coating uncracked and free of tackiness.

Test	Condition	Pass
Slot load	3 kg, 24 hours	Sag 2 mm or less
Full-roll hang	1.5 times load	No strap slip
Strap pull	600 N, 60 seconds	No tear or slip
Buckle cycles	3000 open-close	Closes one-handed
Thermal cycling	Minus 20 °C to 60 °C	Coating intact

5. Batch Judgement and Rework

Judgement belongs to the batch. Within the accept numbers on both counts and the lot passes; reach a reject number and it is reworked and resampled, never sorted. Three pieces are sealed for 12 months as the reference for the next run.

Only restitching and part replacement are allowed. Fabric blemishes, slot errors and colour drift cannot be repaired because the cloth is already cut, so those pieces become second grade or scrap.

Conclusion

Acceptance of a Tool Roll rests on a table an inspector can follow: split the batch, pull the sample, view appearance under fixed light, measure flat after conditioning, test load, pull and cycles, then judge against the counts. Every check carrying a number is what makes a standard for a Tool Roll hold.

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.