Plastic Injection Molding Companies, Custom Plastic Molding

Name: Suppliers
Brand: Suppliers
Price: 99.00 USD

Every shortlist is vetted/ Registry & customs cross-checked/ Certifications surfaced/ Risk flags shown/ No per-deal commission

The short answer

Last updated August 2026

A plastic injection molding company builds a steel or aluminum mold from your part design, then presses molten resin into that mold to produce identical parts at a per-piece cost that falls as volume rises. Tooling is the number that decides the project: aluminum prototype molds commonly run $2,000 to $10,000 and last a few thousand shots, pre-hardened P20 steel runs $15,000 to $60,000 for several hundred thousand shots, and hardened H13 runs $40,000 to $150,000 or more for a million plus. Per-part prices for typical consumer parts land around $0.50 to $5.00, falling toward pennies in a multi-cavity production tool. The single line that makes competing quotes comparable is the SPI mold class you specify in the RFQ.

Why Suppliers

Sourcing an injection molder goes wrong in a way that is easy to miss until the quotes arrive. You send the same STEP file to six plastic molding companies. Two never reply. One comes back at $4,200, one at $31,000, and one at $96,000, and because none of them wrote down which tool they were quoting, the spread looks like a negotiation problem when it is actually three different products. The $4,200 shop quoted a single-cavity aluminum tool that will die around shot 3,000. The $96,000 shop quoted a four-cavity hardened steel tool designed to run for a decade. Both are honest quotes. Neither answers your question until you decide, in writing, how many parts this mold has to make.

Suppliers is the AI sourcing agent built for that decision. Describe the part, the resin, and the annual volume you expect, and the agent finds injection molding companies that genuinely run that part size and material, then lays their tooling cost, mold class, cavitation, cycle time, per-part price, and lead time out side by side. Every match carries its vetting evidence: identity verification, registry and customs cross-checks, surfaced certifications such as ISO 9001 or ISO 13485, and any risk flags worth a second look. The agent shortlists and ranks; you review the evidence and decide who cuts your steel.

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Quotes normalized to one mold class

The agent puts every molder on the same tool specification before comparing them, so a $4,000 prototype tool is never lined up against a $60,000 production tool as if they were the same offer.

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Tooling and per-part cost shown together

Cheap steel with an expensive cycle can cost more over 200,000 parts than expensive steel with a fast one. Both numbers sit in the same row, with a break-even you can read at your real volume.

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Matched to your resin and part size

Glass-filled nylon, medical-grade PC, food-contact PP, and overmolded silicone need different steel, different presses, and different certifications. The shortlist only surfaces shops tooled for what you actually specified.

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Domestic or overseas, compared honestly

Say whether you want a US molder or lower tooling cost in Asia, and the shortlist reflects it with landed cost, lead time, and the practical cost of an engineering change ten time zones away.

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Tool ownership surfaced before you commit

Who owns the mold, where it is stored, and what it costs to move it are surfaced as comparison points, because that clause decides whether you can ever leave the molder who built it.

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Flat price, no commission

One predictable monthly fee in USD. We take no percentage of your tooling or production spend, so nothing pushes you toward a bigger tool or a particular molder.

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How it works

Describe, match, decide.

1

Describe what you need

Type your need in plain English. The agent extracts the structured spec, from quantity and material to target price and destination.

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AI finds & vets

It matches qualified suppliers, cross-checks registry and customs data, surfaces certifications, and flags risk, then ranks the fits.

3

Compare & decide

Review quotes, MOQs, and lead-times side by side, then run RFQ outreach and POs in one place. You stay in control.

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Buyer's guide

What to know before you commit.

Your tooling quote is set by shot count, not part complexity

Almost every buyer walks into injection molding believing the mold quote tracks how complicated the part is. Geometry does matter, and undercuts, side actions, and tight tolerances all add machining hours. But it is rarely the variable that produces a 20x spread between two quotes on the same drawing. The dominant variable is the number of shots you told the molder to design for, because that single number picks the tool steel, and the tool steel drags everything else with it.

Run the same part through three tool specifications and the drawing never changes. An aluminum prototype mold, SPI Class 105, commonly quotes at $2,000 to $10,000. Protolabs, one of the few vendors that publishes a number at all, lists mold cost starting at $1,495 and guarantees its prototyping aluminum tools for at least 2,000 shots. Move to pre-hardened P20 steel and the same geometry typically quotes at $15,000 to $60,000 and is rated in the hundreds of thousands of shots. Move to fully hardened H13, which you need for abrasive glass-filled resins, and you are looking at $40,000 to $150,000 or more, with a life past a million shots. Industry test data consistently shows P20 cavities running 30 percent glass-filled nylon starting to show measurable gate wear somewhere around 200,000 to 300,000 shots, while H13 holds tolerance well past a million under the same conditions.

So the practical instruction is short. Before you send a single RFQ, write down your expected annual volume and the number of years this part will stay in the catalog, multiply them, and put the resulting shot count and a requested SPI mold class in the RFQ itself. Six quotes against one stated mold class are comparable. Six quotes against a silent one are not, and the cheapest number in an uncontrolled set is usually the tool that dies first.

Almost nobody publishes an injection molding price, and that is a sourcing problem

We checked the injection molding capability pages of the three best-known digital manufacturing platforms in August 2026. Exactly one of them, Protolabs, publishes a dollar figure: mold cost starting at $1,495, with no minimum order quantity and standard lead times as fast as seven days. Xometry publishes no dollar figure anywhere on its injection molding capability page and routes you to an instant quoting engine. Fictiv publishes no dollar figure either, quoting lead times such as production-grade steel tooling in weeks but no price at all.

That is not a criticism of any of them. A mold price genuinely depends on geometry, and a published number would be wrong more often than right. But it has a direct consequence for how you should source: because price is invisible until you upload a file, the cost of getting a real number is one CAD upload plus a wait, and buyers routinely settle after two or three quotes because collecting more is tedious. That is exactly the wrong place to stop, since the spread on the same part across honest molders is frequently 10x.

The defense is to make the request cheap to repeat and identical every time. Package the STEP file, the resin and any filler percentage, the expected annual volume, the requested SPI mold class, the cavitation you want quoted, the color or masterbatch requirement, and the tool ownership terms into one brief, then send that same brief to eight or ten shops rather than three. That is the part of the job an agent should be doing for you, and it is why structured RFQ software beats a folder of email threads once you are comparing more than a handful of molders.

Cavitation is where the per-part price is actually won

Once the steel grade is settled, the second lever is how many cavities the mold has. A single-cavity tool makes one part per cycle. A four-cavity tool makes four parts in roughly the same cycle time, because the cycle is dominated by cooling the resin, not by how many impressions the plate carries. The tool costs more, usually well under 4x more for 4x the output, and the per-part machine cost divides by close to the cavity count.

This is why the industry rule of thumb is that per-part injection molded cost for a typical consumer part sits around $0.50 to $5.00 in low cavitation, then falls toward pennies once you are running a multi-cavity hardened production tool at hundreds of thousands of units. The break-even is arithmetic you can do before any quote arrives. Take the extra tooling cost of the higher-cavitation option, divide it by the per-part saving, and you get the volume at which the bigger tool pays for itself. If that number is above your realistic three-year demand, the cheaper tool wins no matter how good the per-part price looks. The same arithmetic decides whether you should be molding at all: our breakdown of injection molding versus CNC machining cost per part runs it against five real tooling tiers.

A family tool is the variation worth asking about when you have several different parts in one assembly. It puts multiple distinct cavities in one mold base, which saves tooling money and press setups but locks the parts into a fixed ratio per shot. It is excellent when you always need one housing and one lid, and a trap when the two parts fail or sell at different rates.

Ask who owns the mold before you ask what it costs

The mold is a physical asset that can weigh several hundred pounds and cost as much as a car, and the contract term covering it is the one most buyers skip. Three arrangements are common. You pay for the tool outright and own it, in which case you can pull it and move it to another molder. The molder amortizes the tool into the per-part price, in which case the tool is theirs and the low per-part price you were quoted is only available from them. Or the tool is owned by you on paper but held by the molder with storage, maintenance, and transfer terms that make retrieving it expensive.

Ask in writing: who holds title to the mold, what a transfer costs, who pays for maintenance and for replacement inserts as the tool wears, how many shots the tool is warranted for, and what happens to the tool if you stop ordering for twelve months. A molder running its own tool room will answer all five in specifics. One that answers in reassurances is a broker placing your work elsewhere, which adds a margin and removes your ability to fix a dimensional problem directly.

The other question worth asking early is what the shop does before it cuts steel. A serious molder returns a design for manufacturability review with named issues: wall thickness variation that will sink, missing draft on a vertical face, a gate location that will leave a witness mark on a cosmetic surface, a rib thicker than 60 percent of the adjoining wall. Getting that review before tooling is far cheaper than discovering it at T1 samples. If you are still deciding whether molding is the right process at all, compare it against CNC machining companies for the first few hundred units, where there is no tool to pay for.

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At a glance

Injection mold options by tooling cost, rated life, and the volume each one suits.

Tool option	Typical tooling cost	Rated life in shots	Time to first samples	Best for
Aluminum prototype tool (SPI Class 105)	$2,000 to $10,000	A few thousand	1 to 3 weeks	Bridge production, pilot runs, design still moving
Pre-hardened P20 steel, single cavity	$15,000 to $60,000	Several hundred thousand	4 to 8 weeks	A proven part at steady annual volume
P20 or hardened steel, multi-cavity	$30,000 to $100,000+	Several hundred thousand	6 to 12 weeks	Driving per-part cost down at high volume
Hardened H13 production tool	$40,000 to $150,000+	1,000,000+	8 to 16 weeks	Abrasive glass-filled resins and long product life
CNC machined parts, no tool	No tooling cost	Not applicable	Days	Under roughly 100 to 500 units, or geometry still changing

Ranges reflect what US and overseas molders commonly quote in 2026 and are a planning guide, not a promise. Protolabs is the one major platform publishing a starting figure, listing mold cost from $1,495 with aluminum prototyping tools guaranteed for at least 2,000 shots (protolabs.com, checked August 2026). Xometry and Fictiv publish no dollar figures on their injection molding pages. Verify every number against a live quote on your own geometry.

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The questions buyers actually search.

How much does injection molding cost?

Injection molding cost is tooling plus per-part cost. Tooling runs roughly $2,000 to $10,000 for an aluminum prototype mold, $15,000 to $60,000 for pre-hardened P20 steel, and $40,000 to $150,000 or more for a hardened H13 production tool. Per-part cost for a typical consumer part lands around $0.50 to $5.00, falling toward pennies in a multi-cavity tool at volume.

How much does an injection mold cost?

A single mold commonly costs between $2,000 and $150,000 depending on the steel grade, cavity count, and part complexity. Protolabs publishes mold cost starting at $1,495 for simple aluminum tooling. The steel grade you request, which is driven by your expected shot count, moves the quote more than the geometry does.

What is the minimum order quantity for injection molding?

Traditional molders often set no formal minimum but need enough volume to justify the tooling investment, which practically means several thousand parts. Digital manufacturing platforms are different: Protolabs states no minimum order quantity and builds cost-effective aluminum tools for runs as small as 25 pieces, at a much higher per-part price.

How long does it take to make an injection mold?

An aluminum prototype tool typically reaches first samples in one to three weeks, and some vendors quote as fast as one to seven days for small simple parts. A production steel tool usually takes four to twelve weeks to cut, plus a sampling and dimensional approval round before the mold is released for production.

Is injection molding cheaper than 3D printing or CNC machining?

Only above a break-even volume. Injection molding carries the tooling cost up front but has a very low per-part cost, while 3D printing and CNC machining have no tooling cost and a much higher per-part cost. The crossover for a typical small plastic part usually falls somewhere between 100 and 1,000 units.

What is the difference between an aluminum and a steel injection mold?

Aluminum tools are cheaper and faster to cut, conduct heat better so cycles run quicker, and wear out after a few thousand shots. Steel tools cost several times more and take longer to build, but pre-hardened P20 lasts into the hundreds of thousands of shots and hardened H13 past a million, including with abrasive filled resins.

Who owns the injection mold, me or the molder?

It depends entirely on the contract, so get it in writing before tooling starts. If you pay for the tool outright you normally own it and can move it. If the molder amortizes tooling into the per-part price, the tool is theirs and the low per-part price is only available from them. Ask about title, transfer cost, maintenance, and warranted shot life.

What is an SPI mold class?

The SPI mold classification is an industry scale from Class 105 to Class 101 that describes how long a mold is built to last. Class 105 is a prototype tool rated under 500 shots, Class 101 is an extremely high production tool rated above one million. Naming a class in your RFQ is what makes competing quotes comparable.

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FAQ

Common questions.

Yes. State the quantity you can commit to and the shortlist prioritizes shops that run aluminum bridge tooling and low volume plastic molding, rather than production houses whose economics only work in the hundreds of thousands.

Yes. Say you want domestic production in your brief and the agent shortlists US molders. Many buyers compare a US shop against an overseas tool room on landed cost, lead time, and how quickly an engineering change can be turned around.

Yes. Both numbers sit in the same comparison, because a low tooling quote paired with a slow cycle can cost more across a production run than a more expensive tool that cycles faster. You can see where the two options cross at your own volume.

Certifications such as ISO 9001, ISO 13485, and food-contact resin handling are surfaced with each match, with the evidence shown. Say what your part has to comply with in the brief and the shortlist filters on it before you start sending RFQs.

Yes. You can send the same structured RFQ to every shortlisted molder from one workspace, keep their tooling quotes, cavitation, cycle times, and lead times side by side, and issue purchase orders without re-keying anything into a spreadsheet.

No. We do identity verification, registry and customs cross-checks, surfaced certifications, and risk flags, with the evidence shown so you can judge it. That is risk reduction, not elimination. First article inspection and dimensional approval are yours to run, and a human should sign off before steel is cut.

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