Quality Control

AQL Inspection Specs for Custom Pins, Coins and Keychains

Q: What does AQL control before shipment?

AQL, or Acceptable Quality Limit, converts a vague quality expectation into a measurable shipment decision. For custom enamel pins, challenge coins, medals, keychains, fridge magnets and metal badges, it defines how many finished pieces are randomly inspected, how defects are classified, and how many defects are allowed before the lot fails. It protects both sides: the buyer avoids paying the balance on an unsellable shipment, and the factory avoids open-ended arguments after goods have already left China.

AQL does not replace the approved golden sample. The golden sample controls design, size, Pantone colors, plating tone, antique finish, attachment, backing card and packaging style. AQL controls production consistency against that sample. Typical failures include scratched plating, loose pin posts, underfilled enamel, epoxy offset, mixed artwork revisions, wrong clutch color, unscannable QR codes, short-packed retail cards and carton quantity errors.

Final inspection is most useful when at least 80% of the order is packed and all SKUs are available. Earlier in-line checks can catch plating, enamel or soldering problems, but packing errors usually appear near completion. AQL works well for repeatable, observable defects. It is not a good tool for subjective decisions such as whether antique brass is warm enough or whether an enamel shade feels premium; those points need signed artwork, Pantone references, plating cards and a physical approval sample before mass production.

Q: Which AQL level belongs on the PO?

For most B2B promotional orders, use ANSI/ASQ Z1.4 or ISO 2859-1, single sampling, normal inspection, General Inspection Level II. This is the standard language most Chinese factories and third-party inspectors understand. It gives a practical sample size without requiring 100% sorting.

A workable default for custom metal promotional products is Critical AQL 0, Major AQL 2.5 and Minor AQL 4.0. Premium retail, licensed merchandise, museum shops, airline gifts and shelf-ready packaging should usually use Major AQL 1.5 and Minor AQL 2.5. Very low-cost event giveaways may stay at Major 2.5 and Minor 4.0; Major 4.0 should only be used when the buyer knowingly accepts more visible cosmetic variation.

Order type	Inspection level	Critical AQL	Major AQL	Minor AQL	Best use
Premium retail pins, brooches or coins	General II	0	1.0 or 1.5	2.5	Licensed logos, museum shops, airline gifts, retail cards
Standard corporate pins or keychains	General II	0	2.5	4.0	Distributor orders, staff gifts, trade shows, campaigns
Mixed promo kits	General II by component	0	2.5	4.0	Pins, coins, lanyards and magnets packed as one set
Low-cost event giveaways	General I or II	0	4.0	6.5	Short-life handouts where minor cosmetic variation is accepted
Child-use or magnet items	General II plus safety checks	0	1.0	2.5	Small parts, magnets, sharp edges, warnings or compliance risk

The AQL level should be agreed before deposit payment because it affects sorting labor, reject allowance and schedule. Tightening from Major 2.5 to Major 1.0 after production is complete usually means paid re-sorting, 2-5 extra working days, and a dispute over who pays for rework or replacement.

Q: How should defects be classified?

Critical defects are safety, legal or severe functional failures. For metal promotional items, critical defects include sharp burrs over 0.10 mm on an accessible edge, detached magnets, pin posts that separate during light pull, broken brooch needles, exposed wire, prohibited materials, missing choking hazard warnings, wrong licensed artwork, mixed customer logos, or an unsupported nickel-free or lead-free claim. Critical AQL should be 0; one confirmed critical defect can fail the lot.

Major defects are issues a normal buyer would reject, return or complain about. Examples include wrong plating finish, missing enamel color, Pantone mismatch beyond the signed tolerance, size outside specification, front-face scratch longer than 3.0 mm, plating blister over 1.0 mm, epoxy overflow onto metal lines, UV print shift over 0.5 mm, loose spinning hardware, jump ring gap over 0.20 mm, unscannable QR code, wrong attachment, wrong backing card, incorrect barcode or carton shortage.

Minor defects are visible but not normally return-worthy when isolated. Examples include a backside polishing line under 1.0 mm, enamel meniscus variation within 0.20 mm, dust under epoxy below 0.30 mm, slight backside plating shade variation, light polybag scuff or minor backing card pressure mark. Upgrade a minor defect to major when it appears on the main logo face, repeats across many pieces, combines with another defect on the same item or affects retail presentation.

• Critical checklist: sharp edge over 0.10 mm, detached magnet, broken post, wrong logo, mixed artwork, prohibited material, missing safety warning, false compliance claim.
• Major checklist: wrong plating, missing color, front scratch over 3.0 mm, blister over 1.0 mm, loose clasp, wrong card, unscannable QR code, short quantity.
• Minor checklist: tiny backside scratch, light polishing mark, dust speck under 0.30 mm, slight enamel wave, minor polybag wrinkle, approved shade variation.
• Briefing rule: attach reference photos because words such as slight, obvious and acceptable are interpreted differently by factories, buyers and inspectors.

Q: What tolerances should inspectors measure?

Do not ask inspectors to judge small metal goods only by eye. Provide numeric tolerances for size, thickness, finish, registration and function. For stamped iron or brass pins under 40 mm, a realistic outer size tolerance is ±0.20 mm. For 40-70 mm badges, medals and keychains, ±0.30 mm is more practical. Cast zinc alloy parts with 3D relief often need ±0.30 mm because mold flow, polishing and plating change edges unevenly.

Thickness should be specified separately from length and width. A 1.5 mm iron soft enamel pin can often hold ±0.10 mm before plating. A 3.0 mm challenge coin is more realistic at ±0.15-0.20 mm after polishing and plating. Decorative nickel, gold, brass, copper, black nickel and rose gold plating is commonly 3-8 microns. Premium corrosion-resistant requests may use 8-12 microns, but excessive plating can soften recessed detail and increase cost.

Artwork placement should use centerline or edge-offset measurements. Screen print and UV print registration should normally be within ±0.20 mm for small logos and ±0.30 mm for larger artwork. Epoxy dome offset should be no more than 0.30 mm on pins below 35 mm and no more than 0.50 mm on larger keychains. Magnet placement should stay within ±0.50 mm of the approved back layout so the item hangs straight on a steel surface.

Check point	Standard tolerance	Tight tolerance	Factory note
Outer size under 40 mm	±0.20 mm	±0.10 mm	Tight limits need simple outlines and controlled polishing
Outer size 40-70 mm	±0.30 mm	±0.20 mm	Large thin badges can distort during polishing or plating
Metal thickness	±0.10-0.20 mm	±0.05 mm	Very tight thickness raises reject rate and unit cost
Print registration	±0.20-0.30 mm	±0.10 mm	Avoid tight limits on curved, domed or 3D surfaces
Epoxy dome offset	≤0.30-0.50 mm	≤0.20 mm	Narrow borders and cutouts make tight doming difficult
Plating thickness	3-8 microns	8-12 microns	Higher thickness improves durability but may soften detail

Q: How many pieces are inspected?

Sample size depends on lot size and inspection level, not on how many cartons are easy to open. Under General II normal inspection, a 500-piece order normally uses an 80-piece sample, while a 5,000-piece order uses a 200-piece sample. The inspector should pull randomly across finished cartons, SKUs and production dates, not from a clean tray prepared by the factory.

For example, a 5,000-piece keychain order under General II uses sample size code L, or 200 inspected pieces. At Major AQL 2.5, the lot passes with 10 or fewer major defects and fails with 11 or more. At Minor AQL 4.0, the same sample passes with 14 or fewer minor defects and fails with 15 or more. Critical defects remain AQL 0.

Multiple designs should not be hidden inside one vague lot. If a shipment contains four pin designs of 500 pieces each, the inspector should sample every design or pull proportionally from each SKU and carton group. For mixed promo kits, inspect each component first, then inspect assembled sets for count, orientation, insert sheet, barcode, carton mark and ship mark.

100% inspection is justified for serialized coins, premium medals, safety-sensitive brooches, reworked lots or retail programs with chargebacks. It still does not guarantee perfection, but it reduces visible escapes. For small metal items, 100% visual sorting commonly adds FOB USD 0.03-0.12 per piece depending on defect criteria, lighting, polybag removal, barcode scanning and re-packing complexity.

Q: What checks apply by product type?

The inspection plan should match the item. A soft enamel pin needs enamel fill, plating, post strength, clutch fit, Pantone color, epoxy edge and backing card orientation checks. A challenge coin needs diameter, thickness, weight, edge finish, relief sharpness, antique wiping, enamel fill and capsule or pouch condition checks. A keychain needs ring strength, jump ring closure, swivel movement, print alignment and packing checks. A fridge magnet needs magnet pull, adhesive bond, flatness and surface protection checks.

For pin posts, a practical pull test is 5 kg for 10 seconds when the solder area and design allow it. For heavier brooches, inspect hinge movement, catch closure and needle straightness; a needle bent more than 1.0 mm from center should normally be major. For keychains, open the split ring to 3.0 mm and confirm it recovers without permanent deformation. Standard jump ring closure gaps should be no more than 0.20 mm.

Magnet performance should be tested on a clean vertical steel plate, not a dusty painted cabinet. Light fridge magnets under 50 mm may only need to hold one A4 sheet. Heavier metal magnets should specify pull force, commonly 300 g, 500 g or 800 g depending on item weight. If the magnet is glued into a recess, add an adhesive bond check after curing and reject magnets that rotate, rattle or lift at the edge.

• Visual checks: plating color, enamel fill, scratches, stains, dust under epoxy, print registration, antique finish, logo sharpness, clean edges.
• Functional checks: post pull, clutch fit, brooch catch closure, split ring recovery, jump ring gap, magnet holding force, swivel movement.
• Dimensional checks: length, width, diameter, thickness, hole size, ring wire diameter, backing card size, carton weight and carton dimensions.
• Packing checks: SKU separation, barcode accuracy, polybag seal, backing card direction, master carton quantity, desiccant if required, carton sequence.
• Document checks: artwork version, Pantone list, plating finish, attachment type, PO quantity, ship mark, destination market and compliance notes.

Q: How do MOQ, FOB price and lead time change?

Stricter AQL affects more than the inspection invoice. It changes production behavior because the factory may need extra polishing, re-plating, enamel repair, hardware replacement, sorting and re-packing. For custom enamel pins, practical MOQs are 100-300 pieces per design, with better pricing at 500, 1,000 and 3,000 pieces. A 25-35 mm soft enamel pin typically quotes FOB USD 0.45-1.20 at 1,000 pieces, depending on metal, plating, color count, epoxy, backing card and attachment. Tight cosmetic sorting can add USD 0.03-0.10 per piece.

Challenge coins often start at 100 pieces per design, but pricing improves at 300, 500 and 1,000 pieces as mold, setup and plating costs spread out. For 40-60 mm zinc alloy or brass coins with enamel and antique plating, typical FOB pricing is USD 1.80-5.50 per piece. Major AQL 1.0 or 1.5 on antique coins can add 2-4 working days because edge finish, wiping consistency and rework take time.

Metal and PVC keychains commonly start at 100-300 pieces per design. Standard FOB ranges are USD 0.55-2.20, while spinner, bottle opener, 3D zinc alloy or retail-carded keychains can exceed USD 3.00. Hardware cycle checks, barcode scanning and individual retail packing add 1-3 working days. Metal enamel fridge magnets require the same plating and enamel controls as pins; printed acrylic or soft PVC magnets may be cheaper but still need magnet bond and pull-force checks.

Normal custom metal promotional goods follow a predictable schedule: artwork confirmation in 1-2 days, tooling and pre-production sample in 5-10 days, mass production for 500-5,000 pieces in 10-20 days after sample approval, and final inspection plus rework buffer in 2-5 days. Before Chinese New Year, National Day, major trade shows or peak event seasons, add 7-14 days because plating, enamel and packing subcontractors become bottlenecks.

Q: What wording should go into the RFQ and PO?

Inspection wording should be short, measurable and tied to payment. Avoid phrases such as factory must ensure best quality because they have no operational meaning. State the inspection standard, AQL levels, defect classes, tolerances, sample references, function tests, reinspection responsibility and shipment approval rule.

A practical clause is: Final inspection to ANSI/ASQ Z1.4, single sampling, normal inspection, General Inspection Level II. AQL: Critical 0, Major 2.5, Minor 4.0 unless otherwise stated. Inspection must include visual, dimensional, functional, packaging and quantity checks against the approved golden sample, signed artwork, Pantone list, plating specification and PO. Shipment requires buyer approval of the inspection report before balance release.

For premium or licensed orders, add: Major defects include visible logo distortion, wrong trademark color, unapproved artwork version, barcode mismatch, retail card damage or any front-face cosmetic defect visible at 30 cm under normal daylight. For child-use or magnet items, add pull-force, sharp-edge, small-part and warning-label checks based on the destination market requirement.

• PO checklist: AQL standard, defect classification, sample reference, size tolerance, thickness tolerance, plating micron target, function tests and packing spec.
• Sampling checklist: lot quantity, SKU split, carton selection method, inspection level, sample size, acceptance number and reinspection rule.
• Evidence checklist: defect close-ups, caliper photos, pull test photos, magnet test photos, carton labels, sealed cartons and quantity records.
• Payment checklist: balance release condition, failed inspection handling, rework timing, reinspection cost responsibility and partial shipment approval rule.

Set these requirements before quotation, not after production. Send the supplier artwork, target quantity, item size, base material, plating finish, attachment, packaging, destination market and requested AQL. Ask them to confirm MOQ tiers, FOB price range, sample lead time, mass lead time, realistic tolerances and whether inspection sorting is included. For ZheCraft projects, the same AQL checklist can be built into the quotation, pre-production sample approval sheet, in-line QC and final packing inspection so the buyer, factory and inspector work from one measurable standard.

Have a project? Send your artwork and target quantity and we’ll reply with a detailed quotation within 12 working hours.