Molding, tooling and sourcing terms, in plain English.

Acrylonitrile butadiene styrene, a tough, rigid, low-cost plastic used for housings, enclosures and consumer products. It molds cleanly, takes paint and plating, and is a common rigid base under a soft overmold.

Also called: Acrylonitrile butadiene styrene

See: Insert molding & overmolding

The worst average defect rate a buyer agrees to accept when a lot is checked by random sampling under ISO 2859-1 or ANSI/ASQ Z1.4. The standard sets the sample size and how many defects pass or fail the lot. A common choice for consumer goods is 2.5 for major defects and 4.0 for minor defects at General Inspection Level II, with critical defects not accepted.

Also called: Acceptable quality limit

See: Inspection step, Line watch, AQL sampling calculator

The hollow in a mold that forms the outside shape of the part. A one-cavity mold makes one part per cycle; a four-cavity mold makes four. The word is also used for the mold half that holds that shape.

See: What an injection mold costs

An Incoterms rule for sea and inland waterway shipments. The seller pays freight and minimum insurance to the destination port, but risk passes to the buyer once the goods are loaded on board the vessel at origin.

See: Freight step

The force an injection press uses to hold the mold closed against the injection pressure. It is sized from the projected area of the parts and runner; too little tonnage lets the mold open slightly and causes flash.

Also called: Clamping force

See: Molding step

A hinged, one-piece thermoformed plastic package that folds closed around a product. It can be heat sealed or snapped shut and often carries a printed paper insert.

See: Blister & clamshell packaging

A runner system that is not heated, so the plastic in it solidifies each cycle and comes out with the parts. The runner is cut off and scrapped or reground. Cold runner molds cost less to build than hot runner molds.

See: Mold step

The mold half, or the inserted pieces, that form the inside of the part: the inner walls, holes and pockets. Cores and cavities together make the part shape.

Paperboard made of a fluted middle layer glued between flat liners. Flute size (such as E, B or C) sets the thickness and strength. It is the usual material for shipping cartons and for most POP displays.

See: Point of purchase displays

The country US Customs treats as where a product was made. When parts from several countries are combined, origin goes to the country where the last substantial transformation happened: where the goods became a new article with a different name, character or use. Origin drives duty rates and marking.

Also called: COO

See: Taiwan & tariffs

The time for one full molding cycle: mold close, inject, pack, cool, open and eject. Cooling is usually the longest part. Cycle time and cavity count together set the output per hour and the piece price.

See: Molding step

A steel pin in the mold that pushes the finished part off the core when the mold opens. Ejector pins usually leave small round marks, so their location is agreed on a non-cosmetic face.

A formal, documented change to a released drawing, part, material or process. An engineering change notice records what changed and from which date or lot, so production and inspection work from the same revision.

Also called: Engineering change notice

An Incoterms rule where the seller only makes the goods available at its own premises. The buyer takes on loading, export clearance, freight and all risk from that point.

See: Freight step

The opening where molten plastic enters the cavity from the runner. Gate type and location affect how the part fills, where weld lines fall and where a small vestige is left on the part.

See: Mold step

An approved production sample, signed off by the buyer and kept by both sides as the physical standard that later lots are compared against for color, fit, finish and function.

Also called: Approved sample, Reference sample

See: The golden sample was perfect. Lot three was not.

The International Chamber of Commerce's standard trade terms (current edition: Incoterms 2020). Each three-letter rule, such as EXW, FOB or DDP, states who pays for and who carries the risk of each leg of a shipment. They do not transfer ownership or set the price.

Also called: Incoterms 2020

See: Freight step

Placing a metal or plastic component, such as a threaded nut, a pin or a stamped part, into the mold and shooting plastic around it so the two become one part.

See: Insert molding & overmolding

A visible line where two flow fronts of plastic meet and fuse, such as around a hole. It can be a weak spot as well as a cosmetic mark, so gate location is planned to put it somewhere harmless.

Also called: Weld line, Meld line

The outer shipping carton that holds a set number of retail units or inner packs. Its size, count and weight set pallet and container loading.

Also called: Shipping carton, Outer carton

See: Custom packaging, Packaging step

The tool steel the cavity and core are cut from. P20, a pre-hardened steel, is common for moderate volumes; H13 and other hardened steels last longer and cost more to machine. Aluminum is used for short-run and prototype tools.

Also called: Tool steel, P20, H13

See: Mold step, Why mold quotes vary

The smallest order a factory will run for a given item. It depends on setup time, material minimums and the number of cavities in the tool, and it is often negotiable in exchange for a higher unit price or a machine fee.

See: Minimum order quantity, what is negotiable

OEM (original equipment manufacturer) production makes a product to the buyer's own design. ODM (original design manufacturer) means the factory's own design is sold under the buyer's brand.

Also called: Original equipment manufacturer, Original design manufacturer

See: Engineering & tooling

Molding a second material over a part that was molded first, usually a soft TPE or TPU over a rigid plastic, for grips, seals and bumpers. It can be done in two separate molds or in one two-shot cycle.

Also called: Over-molding

See: Insert molding & overmolding

Measuring and scanning an existing part to rebuild a drawing and 3D model when the original files are missing. Tolerances, material grade and surface finish have to be confirmed, because a sample does not record them.

See: Reverse engineering from a sample

Recycled PET, made from post-consumer bottles and packaging. It forms like virgin PET and usually costs more.

Also called: Recycled PET, R-PET

See: Blister & clamshell packaging

The channels in a mold that carry molten plastic from the sprue to the gates of each cavity. They are either cold (scrapped each cycle) or hot (kept molten).

Also called: Runner system

See: Mold step

The first parts shot from a new mold, used to check fit, dimensions and appearance. Corrections follow and are re-sampled as T2, T3 and so on until the parts are approved.

Also called: First shot, T1 trial

See: Mold step, Molding step

Packaging that shows visible damage if it has been opened, such as a sealed blister, a breakaway band or a security label, so a store or customer can see if the product was accessed.

Also called: Tamper evident

See: Blister & clamshell packaging

A surface finish etched or blasted into the mold steel, from a light matte to a deep grain, specified by standards such as Mold-Tech or VDI numbers. Deeper textures need more draft.

Also called: Mold texture, VDI, Mold-Tech

Heating a plastic sheet until soft and pulling it over or into a mold with vacuum or pressure. It is how blisters, clamshells and trays are made, with much lower mold cost than injection molding.

Also called: Vacuum forming

See: Blister & clamshell packaging

Moving an existing mold from one factory to another. It usually needs a mold inspection, repair of worn steel, new sampling and a first article check at the new factory.

Also called: Mold transfer, Tooling transfer

See: Engineering & tooling

Who legally owns a mold the buyer paid for. The purchase terms should say that the buyer owns it, that it is marked as such, and on what terms it can be moved to another factory.

See: Payment terms in Asia

Thermoplastic elastomer: a rubber-like plastic that can be injection molded and remelted. It is the usual soft-touch material for grips, seals and overmolds.

Also called: Thermoplastic elastomer

See: Insert molding & overmolding

Thermoplastic polyurethane: a tough, abrasion-resistant elastomer used for phone cases, cable jackets and overmolds that need more wear resistance than a typical TPE.

Also called: Thermoplastic polyurethane

See: Insert molding & overmolding

Molding two materials or colors in one machine cycle: the first shot forms the base, the mold rotates or shifts, and the second shot is molded onto it. It suits high volumes of soft-grip and two-color parts.

Also called: 2K molding, Double-shot molding, Multi-shot molding

See: Insert molding & overmolding

The thickness of a plastic part's walls. Keeping it as even as practical is a first rule of part design, because thick areas cool slowly and cause sink, voids, warp and longer cycles.

Also called: Nominal wall

See: Drawing & CAD step

Distortion of a part out of its intended shape after molding, from uneven cooling or uneven shrinkage between thick and thin areas or across fiber direction.

Also called: Warpage