AQL Sampling for Machined Parts: ANSI/ASQ Z1.4 (ISO 2859-1)

Sample Size Code Letters (General Inspection Level II)

Lot size	Code letter	Sample size
2 to 8	A	2
9 to 15	B	3
16 to 25	C	5
26 to 50	D	8
51 to 90	E	13
91 to 150	F	20
151 to 280	G	32
281 to 500	H	50
501 to 1,200	J	80
1,201 to 3,200	K	125
3,201 to 10,000	L	200

Accept / Reject Numbers (single sampling, normal inspection)

Sample size	AQL 1.0	AQL 2.5
n = 20	Ac 0 / Re 1	Ac 1 / Re 2
n = 50	Ac 1 / Re 2	Ac 3 / Re 4
n = 80	Ac 2 / Re 3	Ac 5 / Re 6
n = 125	Ac 3 / Re 4	Ac 7 / Re 8

Example: a shipment of 500 machined housings at level II uses code H, sample size 50. At AQL 2.5 the batch accepts with 3 or fewer defects and rejects at 4. The full Z1.4 master table covers reduced and tightened inspection and other AQL values; we apply the published table exactly.

Our Shipment Inspection Flow

1. Agree the quality plan at quoting: AQL levels, level II default, characteristic list
2. First article: 100 percent inspection of drawing characteristics, FAI per AS9102 on request
3. Production batch: AQL sampling per the agreed plan, plus material certificate and CMM report on critical features
4. Shipment documentation: inspection record with Ac/Re decision stated, in English

FAI / FAIR Reporting Capability

First article inspection per AS9102 on request, the same block we apply across quality pages: Form 1 (product accountability), Form 2 (material and process accountability), Form 3 (characteristic accountability with ballooned drawings), backed by CMM measurement data. Reports are issued in English and filed per part number, so repeat orders reuse the same FAI package.

Related: Inspection & QC, tolerance standards.

AQL Sampling FAQ

Which AQL do you recommend for machined parts?

Our default proposal: critical and functional dimensions at AQL 0.65 or 100 percent measurement on CMM characteristics, cosmetic features at AQL 2.5, general inspection level II. Final numbers are agreed per order in the quality plan.

Do you inspect to ANSI/ASQ Z1.4 or ISO 2859-1?

Both are equivalent; the sampling tables we apply are the Z1.4 (ISO 2859-1) single sampling plans at general inspection level II as published.

Can AQL inspection be combined with FAI?

Yes and usually is: the first article gets 100 percent characteristic inspection, and AQL governs the production batches that follow.