What drives injection molding part cost

Machining and printing carry no tooling, so the cost per part barely moves with volume. Molding front-loads the tool and then makes parts for very little, so its cost per part falls steeply. The crossover is the volume at which the tool has paid for itself. Where it sits depends on part size, tool complexity and cycle time, not on a rule of thumb.

A worked example, in relative units

Nobody quoting a real part should trust a national average resin price or a generic shop rate, because both move month to month and press to press. What is stable is the shape of the calculation, so here it is worked through with the tooling and piece cost expressed as multiples of a single baseline, the material and process cost to make one part once the tool exists. Treat the multiples as illustrative, sized to show how steeply the curve falls, not as a quote for any specific part; your own tool cost and cycle time depend on your geometry, material and finish, and we state both as separate numbers on every quotation we send.

The total collapses toward the process cost as volume rises. Past a few thousand pieces the tool is nearly paid off, and the number that matters is almost entirely the process cost, driven by cycle time and material. That is also why a molder quoting "per part" without naming a volume has told you nothing: the same tool and the same part can sit anywhere on that curve.

Cycle time is the largest lever inside the process-cost number, and cooling is the largest part of cycle time, so it is worth knowing the shape of that relationship too. As a rule of thumb used across the industry for an unfilled engineering resin such as ABS or PC, cooled by water at a typical mold temperature, cooling time in seconds runs roughly two to three times the square of the nominal wall thickness in millimetres. A 1 mm wall might cool in two to three seconds; the same part at a 3 mm wall, only three times thicker, can take eighteen to twenty-seven seconds, nine times as long, because heat has to travel a squared distance, not a linear one. That squared relationship, more than any other single fact, is why "reduce wall thickness where the function allows" is the first lever we list above rather than the last.

Injection molding cost in India

The mechanics above hold everywhere. Three things move differently for a part molded and bought inside India.

Tool steel is usually sourced domestically. Aluminum and P20, the two steels covering most production tooling, are readily available and machined domestically, so a standard tool carries no import duty and its lead time is not exposed to a shipping schedule. Hardened steels such as H13, or stainless where corrosion resistance matters, sometimes involve imported blanks or specialty coatings; ask which steel in your quote is sourced how, since that is one more line that can move a tooling lead time.

Resin is where the import line actually shows up. Several of the engineering and high-performance resins in the table on our capabilities page, PC, PA66, POM, PEEK and PEI among them, are largely imported rather than produced domestically, so their landed cost carries duty and freight on top of the base resin price. That pushes material's share of piece price higher on these grades in India than the commodity examples above suggest, and it is a real reason to nominate the exact grade early rather than defaulting to an engineering resin out of habit. Commodity resins, PP, ABS, PE and PA6 chief among them, are produced domestically at scale and do not carry that same import line.

Labour is a smaller share of piece price than on a US or EU quote; machine time is not. Press depreciation, power, and skilled-operator time still price by the hour regardless of country, so cycle time stays the dominant lever it is everywhere else on this page. Do not expect a domestic quote to be proportionally cheaper across every cost driver just because it is domestic.

GST applies to both the tooling invoice and the piece price, the same as any other manufacturing service in India. Ask for a GST-inclusive figure on the quotation itself, so the number you are comparing against an overseas landed-cost quote is the number you will actually pay, not a pre-tax figure that looks lower than it is.

What does travel differently, and rarely gets its own line on a quote: a part sourced and shipped within India by road skips the international freight, customs clearance, and import-duty stack that a landed-cost quote from an overseas molder has to carry on the finished part. That is the checkable version of buying local, separate from any claim that the piece price itself is lower.

Minimum order quantity

Injection molding does not have a minimum order quantity in the way a distributor's price break does. Nobody is refusing to sell you 200 parts. What sets a practical floor is the same volume crossover shown above: below a few hundred pieces, the tooling multiple in that first row of the table gets so large that CNC machining or 3D printing, which carry no tool at all, usually land cheaper even though their per-part price is higher. We do not carry a contractual MOQ; our own economic floor sits at roughly 500 pieces, and below that we typically quote the part in CNC or 3D print instead and say so rather than sell you a tool that will not pay for itself. See on-demand injection molding for how we handle that lower band, and our capabilities page for the standing specification.

How to sanity check a quote you already have

• Ask for tooling and piece price as two separate line items. A single bundled number hides which one you are actually negotiating.
• Ask what cavitation the piece price assumes. A quote at four cavities and a quote at one cavity for the same part are not comparable numbers.
• Ask what annual volume the piece price is based on. Per the table above, the same part can be quoted at wildly different per-part prices depending on the volume assumed, with neither number being wrong.
• Ask for the resin grade, not the family, on the quotation itself. PA66 and PA66-GF30 do not cost the same to mold, and a quote that says only "nylon" has not committed to anything checkable.
• Ask what the quoted lead time actually covers: tool build, first article, or production release. These are three different dates, and a number that does not say which one is not comparable to another molder's number.

Have not sent an RFQ yet? See how to get an accurate injection molding quote for the checklist that gets a firm number back on the first pass.