Quality Control

Final Inspection AQL for Custom Pins and Keychains

Final Inspection Is the Last Controllable Gate

The highest-risk moment in a custom metal order is usually not artwork approval. It is the final week, when 20,000 enamel pins or keychains are packed, the air booking is open, and the buyer is asked whether final inspection is really needed. If the buyer relies on factory photos or checks only the top cartons, mixed plating tones, loose pin posts, missing backstamps, weak split rings, wrong barcode labels or short-packed cartons can move directly into an event warehouse or retail DC.

A useful final inspection is not a general request to check quality. It defines the inspection timing, sampling plan, AQL limits, defect classes, measurement tolerances, carton checks and failure response before production starts. For enamel pins, brooches, metal keychains, challenge coins and similar small metal promotional items, the standard should be objective enough that a factory QC team, third-party inspector and buyer can reach the same pass or fail decision.

At ZheCraft, we normally schedule final random inspection when 100 percent of production is complete, 100 percent of accessories are available, and at least 80 percent of the order is export packed. That timing is late enough to catch mixed SKU and packaging errors, but still early enough to sort, relabel, repair or remake before goods leave Yiwu or another China export hub.

Lock Inspection Timing, MOQ and Lead-Time Assumptions

Inspection should be tied to packing status, not only to the promised ship date. If inspection happens before backing cards, polybags, retail boxes and master cartons are ready, the report may miss the errors that most often delay receiving: wrong PO labels, missing warning text, incorrect carton sequence, mixed attachments and short counts. For most B2B orders, the cleanest rule is final random inspection at 100 percent finished goods and 80 to 100 percent packed goods.

For common custom metal items, production lead time normally runs 12 to 18 days for soft enamel pins after artwork approval, 15 to 25 days for epoxy, glitter, spinner or multi-attachment pins, 18 to 28 days for die-cast zinc alloy keychains, and 20 to 35 days for challenge coins with dual plating or edge numbering. These ranges assume normal MOQ and no safety testing backlog. Add 3 to 7 days for pre-production sample approval, 1 to 2 days for final inspection, and a realistic correction buffer before freight handover.

MOQ affects both production stability and inspection value. A practical MOQ is often 100 pieces per design for simple enamel pins, 300 pieces per design for zinc alloy keychains with custom hardware, and 500 pieces per design for complex coins or retail-packed programs. Typical FOB China pricing, excluding tooling and freight, may range from USD 0.35 to 1.20 per 25 mm soft enamel pin at 500 to 5,000 pieces, USD 0.85 to 2.80 per die-cast keychain at 300 to 3,000 pieces, and USD 1.20 to 4.50 per 40 to 50 mm challenge coin at 300 to 2,000 pieces. Lower prices usually mean thinner plating, looser cosmetic tolerance, simpler packaging or fewer inspection points.

Do not book inspection on the same day as container loading unless the order is low value and low risk. A safer buffer is 3 to 5 calendar days before air shipment handover and 5 to 7 calendar days before sea shipment closing. If rework is needed, allow 1 to 3 days for sorting, 2 to 5 days for repacking or relabeling, 5 to 10 days for replating or enamel repair, and 12 to 20 days for remade tooling or a replacement batch.

Use AQL Numbers That Match Commercial Risk

AQL means acceptable quality limit. It is not a promise that the shipment contains that exact defect percentage. It is a statistical sampling rule, commonly based on ISO 2859-1 or ANSI/ASQ Z1.4, that tells the inspector how many units to check and how many defects trigger rejection. For most custom pins and keychains, General Inspection Level II with AQL 0 for critical defects, AQL 2.5 for major defects and AQL 4.0 for minor defects is a practical starting point.

For licensed retail pins, premium corporate gifts, child-facing products or safety-sensitive attachments, tighten major defects to AQL 1.5 and minor defects to AQL 2.5. For low-cost event handouts with short service life, some buyers use AQL 4.0 for major and 6.5 for minor defects, but brand color, logo accuracy, sharp edges and attachment security should never be relaxed. Critical defects should remain AQL 0, meaning one confirmed critical defect fails the lot.

Sampling size depends on lot quantity. Under General Inspection Level II, a 1,201 to 3,200 piece lot normally uses code letter K and a 125-piece sample; at AQL 2.5, the lot passes with 7 or fewer major defects and fails at 8. A 3,201 to 10,000 piece lot normally uses code letter L and a 200-piece sample; at AQL 2.5, it passes with 10 or fewer major defects and fails at 11. A 10,001 to 35,000 piece lot normally uses code letter M and a 315-piece sample; at AQL 4.0, it passes with 21 or fewer minor defects and fails at 22.

Order Type	Typical MOQ	Suggested Level	Critical AQL	Major AQL	Minor AQL	Typical FOB Range
Licensed retail pins or coins	300 to 500 pcs/design	General II	0	1.5	2.5	USD 0.80 to 4.50/pc
Corporate gifts and event badges	300 to 1,000 pcs/design	General II	0	2.5	4.0	USD 0.45 to 2.80/pc
Simple giveaway pins	100 to 500 pcs/design	General I or II	0	4.0	6.5	USD 0.35 to 1.20/pc
Child-facing pins or keychains	500 pcs/design	General II	0	1.5	2.5	USD 0.70 to 3.20/pc

Classify Defects Before the Inspector Arrives

Defect classification must be agreed before production. A report is not useful if the buyer and factory argue after inspection whether a weak magnet, wrong backstamp or 1 mm plating scratch is major or minor. The approved artwork, golden sample, color reference, packaging file and defect classification sheet should all carry the same revision date.

Critical defects create safety, legal or complete usability risk. For pins and brooches, examples include exposed sharp burrs above 0.2 mm on wearable edges, pin posts that detach under a light pull, incorrect child safety warning, swallowed-size magnets used in a child-facing item, lead or cadmium non-compliance where testing was specified, or nickel exposure where nickel-free plating was required. Critical defects should normally trigger automatic failure and containment.

Major defects make the product unsuitable for normal use or clearly different from the approved sample. Examples include wrong plating finish, Pantone enamel color visibly outside the agreed delta or approved chip, missing logo, wrong backstamp, reversed artwork, loose keyring, weak magnet, broken epoxy dome, severe enamel underfill, missing attachment, incorrect retail barcode or pin post placement more than 1.0 mm from the approved location. For anti-rotation dual-post pins, post spacing should normally stay within ±0.5 mm.

Minor defects are cosmetic issues that do not seriously affect function, brand recognition or resale value. A reverse-side plating speck below 0.3 mm, light polishing line visible only at 30 to 40 cm, or tiny non-logo color dot may be minor. Repeated minor defects can still fail the lot if the count exceeds the AQL allowance or if the defects create an inconsistent shelf appearance.

• Classify safety risks, wrong item, wrong material, missing legal markings and failed compliance claims as critical.
• Classify functional failure, visible logo error, wrong color, wrong plating, incorrect barcode and missing accessories as major.
• Classify small reverse-side scratches, slight polishing marks and tiny non-logo specks as minor when within agreed limits.
• Inspect at 30 to 40 cm under 600 to 1,000 lux white light; do not use microscope standards unless specified.
• Define tools in advance: digital caliper, pull gauge, feeler gauge, vertical steel plate, Pantone reference, plating chip and golden sample.

Measure Dimensions, Plating and Function

Small metal promotional products can look acceptable in photos while failing basic checks. Final inspection should measure length, width, thickness, weight, attachment placement, plating coverage, color match, packaging count and carton weight. For die-struck or cast pins under 50 mm, a common dimensional tolerance is ±0.2 mm on main length and width, ±0.15 mm on thickness, and ±5 percent on weight unless the design must fit a holder, display tray or mechanical part.

Plating thickness is not always measured during standard final inspection because many inspectors do not carry XRF equipment. If corrosion resistance or nickel-free claims matter, specify the plating stack before production and request XRF spot checks or factory bath records. Decorative flash layers on low-cost promotional items may be only 0.03 to 0.08 microns. More durable nickel, brass, black nickel, antique gold or imitation gold finishes are often specified around 0.10 to 0.30 microns, while higher-wear retail programs may require thicker deposits and salt-spray testing.

Functional checks should reflect the item type. Standard lapel pin posts can be pull-tested at 2 to 3 kgf when the construction allows it; heavier brooches may require 3 to 5 kgf. Split rings should close without a visible gap above 0.3 mm after assembly. Lobster clasps should spring back fully after three manual cycles. Magnets should hold the approved sample load on a clean vertical steel plate for at least 30 seconds without sliding. Epoxy domes should show no open bubbles, lifted edge or cloudy patch in the logo area.

Check Item	Typical Spec	Tool or Method	Fail Example
Main size	±0.2 mm for items under 50 mm	Digital caliper	45.0 mm approved, 44.5 mm found
Thickness	±0.15 mm unless otherwise agreed	Digital caliper	1.8 mm specified, 1.45 mm found
Pin post position	±1.0 mm standard; ±0.5 mm for dual-post alignment	Caliper from edge datum	Badge tilts on garment
Split ring gap	≤0.3 mm after assembly	Visual check and feeler gauge	Ring opens during pull check
Plating thickness	0.10 to 0.30 microns when specified for durable decorative finish	XRF spot check	Flash layer wears during handling
Magnet hold	Holds approved load for 30 seconds	Vertical steel plate	Fridge magnet slides under own weight

Inspect Cartons as Carefully as the Product

Many final inspection failures are packing failures, not metalwork failures. Incorrect counts, mixed designs, missing clutches, wrong backing cards, unscannable barcodes or carton marks that do not match the forwarder booking can delay receiving even when the pins themselves are acceptable. For distributor and retail orders, one wrong carton label can break the link between the purchase order, warehouse ASN and customer shipment.

A practical carton inspection starts with quantity and weight. Gross weight should usually stay within ±0.5 kg of the approved packing plan for small metal items, and any carton that feels unusually light or heavy should be opened. Inner quantities should be fixed: for example, 100 pins per inner polybag, 500 pieces per inner carton or 1,000 pieces per master carton, depending on item weight and customer handling. Mixed-color or mixed-design cartons should be avoided unless the packing list clearly defines the assortment.

Dense metal products need stronger export packing than paper giveaways. We normally recommend 5-ply corrugated cartons, reinforced tape, inner moisture protection where needed, and gross weight below 15 kg for pins or below 18 kg for coins and keychains unless the buyer approves otherwise. Safe master carton sizes are often around 35 x 25 x 25 cm or 40 x 30 x 25 cm; tall, narrow cartons crush more easily and are harder to palletize. Retail boxes, acrylic displays and gift tins may need a simple drop check before shipment.

• Open cartons from the beginning, middle and end of the packed lot, not only the easiest cartons to reach.
• Verify SKU, design number, plating color, attachment type, backing card and quantity against the packing list.
• Check barcode scanability, warning labels, suffocation text, polybag size and country-of-origin marking where specified.
• Confirm carton marks include PO number, item code, quantity, gross weight, net weight, carton sequence and destination.
• Reject cartons with crushed corners, wet marks, weak tape, loose strapping, mixed loose accessories or unapproved substitutions.

Use Golden Samples, Defect Boards and Revision Control

A golden sample shows the approved product, but it does not define every borderline condition. A defect board, even a controlled photo sheet, helps inspectors and production workers judge enamel dust, plating pits, epoxy bubbles, scratches, color overflow, burrs, offset printing, poor laser engraving and weak attachments. The best time to build this reference is during sampling or first article review, not during final inspection.

Each reference should state the measurable rule. For example: acceptable plating speck under 0.3 mm on reverse side only; reject any front-logo scratch visible at 40 cm; reject enamel overflow touching text; accept color shift only if it matches approved Pantone chip under D65 or equivalent daylight. Without these notes, the factory may treat an approved sample as permission to repeat every small imperfection on a larger scale.

For repeat orders, keep the golden sample, defect board, color card, plating chip and packing sample under one revision code. ZheCraft normally labels controlled samples with item number, version date, base metal, plating finish, enamel type, attachment, packaging method and approved artwork file name. This is important when a buyer reorders after 6 or 12 months and expects the new lot to match the previous shipment even if raw material, plating bath or enamel supplier has changed.

Decide Rework, Sorting or Remake Quickly

A failed inspection does not automatically mean the entire order must be remade. If defects are concentrated in one plating rack, one production shift, one carton range or one design, sorting can recover most usable pieces. Sorting 5,000 to 20,000 pins for visible front-side defects usually takes 1 to 3 working days; repacking corrected goods can add another 1 to 2 days. A 100 percent functional check for posts, magnets or keyrings takes longer because every attachment must be handled.

Some failures are realistic to correct. Loose clutches, missing polybags, wrong carton labels, unsealed retail boxes and mixed quantities can usually be fixed quickly. Light enamel underfill, polishing haze or small plating stains may be repairable if the surface allows it. Wrong mold size, incorrect logo relief, wrong base metal, deeply pitted plating, unsafe sharp edges or failed compliance claims usually require remake or formal buyer concession because rework creates inconsistent appearance or does not remove the risk.

The commercial decision should be documented. If an event date is fixed, a buyer may accept minor reverse-side defects with a written concession, reduced price or replacement plan. Do not accept critical defects, weak attachments, sharp burrs, wrong branding or non-compliant materials to protect the schedule; these issues create higher downstream cost after distribution. A clear inspection standard makes the decision faster because the shipment either meets the agreed criteria or follows a defined recovery path.

Failure Type	Best Action	Typical Extra Time	Buyer Decision Point
Wrong carton labels	Relabel and recheck	1 to 2 days	Confirm label file and carton sequence
Mixed attachments	Sort and replace hardware	2 to 4 days	Decide whether 100 percent check is required
Visible plating pits on front	Sort or replate if feasible	3 to 10 days	Confirm whether replating changes color tone
Wrong artwork relief	Remake affected lot	12 to 20 days	Approve new sample or revised schedule
Weak pin posts	Rework or remake depending on solder issue	3 to 12 days	Require pull test after correction

Before placing the purchase order, add a one-page final inspection standard to the RFQ or order confirmation. For a normal corporate order, start with General Inspection Level II, AQL 0 critical, 2.5 major and 4.0 minor. Add exact checks for size, thickness, attachment strength, magnet holding, plating finish, color match, backstamp, packaging count, barcode scanability and carton marks. For retail, licensed, outdoor or child-facing programs, tighten major defects to AQL 1.5 and define safety-related defects as automatic failure.

If you are sourcing from ZheCraft, send the approved artwork, golden sample requirements, target MOQ, FOB budget, packaging file and shipment deadline together with the inspection standard. We can align production, internal QC and final random inspection around the same criteria, then flag realistic rework time before the goods leave China. The goal is not to reject more shipments; it is to make the pass or fail decision clear while there is still time to fix the problem.

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