What “PEEK manufacturer” actually means in China

The word “manufacturer” hides three different businesses. Buyers lose money confusing them.

First: resin and semi-finished suppliers. Companies like PEEKChina, ZYPEEK, and Hengbo sell pellets, rod, sheet, tube, and film. Some mold parts too. But material is their core business. Need stock shapes to machine yourself? They’re your people. Need a complex molded part? You may be at the wrong desk.

Second: mould shops. They build the steel tool. Many of the “Top 10 PEEK precision mould” names near Taizhou and Dongguan are tooling makers first. They cut molds. Sometimes for other people’s presses.

Third: custom injection molders. These shops shoot your part, shift after shift, on machines built for it.

Here’s the trap. Genuine PEEK runs roughly $80 to $120 per kilogram, and some specialty grades cost more. So a quote far cheaper than the rest isn’t a deal. It’s a warning. Either the resin isn’t what they claim, or they’re a generic shop that’s never run PEEK. They underpriced because they don’t know what’s coming.

A real PEEK manufacturer for a production part is the third kind. And they can prove it.

Can PEEK even be injection molded?

Yes. PEEK molds on high-temp machines with barrel temperatures around 350–400°C, with wear-resistant screws and a hot mold held at 170–200°C. Aerospace, medical, and semiconductor shops do it daily. It’s just unforgiving.

Four things make PEEK harder than a normal resin:

• Melts at 343°C. Real-world barrel settings run 350–400°C, with melt typically around 360–390°C. A standard ABS press built for 200–250°C melt can’t touch it — you need a high-temp machine with a barrel and screw rated above 400°C.
• Soaks up water. PEEK is hygroscopic. Dry to below 0.02% moisture — typically 3 hours at 150°C in a desiccant dryer. Skip it and you get splay (silver streaks), bubbles, and a polymer that’s degraded before it ever sees the cavity.
• It’s abrasive. Filled grades — especially GF30 and CF30 — chew through soft tooling, standard screws, and barrels. Hardened steel cavities and bimetallic or wear-resistant barrels aren’t optional.
• Needs a hot mold. Hold mold temp at 170–200°C so the part crystallizes properly. PEEK is semi-crystalline. A cold mold quenches the polymer into a largely amorphous state — the part looks fine but loses heat resistance, chemical resistance, and creep performance. That’s a defect that doesn’t show up until the part is in service.

That last point is where generic shops blow it. They run PEEK like a commodity resin. The part looks fine. Then it cracks in the autoclave three weeks after it lands at your dock.

PEEK process window: the starting numbers

If a supplier can’t quote process numbers, they haven’t run PEEK. Here’s what a competent shop should already know before they bid your job.

These are starting points for sampling, not finished recipes. The actual settings come from the resin maker’s data sheet for your specific grade, then get tuned during first-shot trials. The order to tune is pressure first, then speed, then temperature — not all at once.

What PEEK injection molding actually costs

A simple PEEK mold from a China supplier usually runs $3,000 to $8,000. Per-part price rides mostly on resin. PEEK is pricey enough that on small parts, material beats machine time.

Your cost splits in two. Tooling, paid once. Piece price, paid on every part.

Tooling depends on part complexity, cavity count, steel grade, and tolerance. For PEEK you want hardened steel. H13 hot-work steel, heat-treated to roughly 44–50 HRC, is the standard pick for cavities and cores — it holds up at the 170–200°C mold temperatures PEEK demands, and it resists the abrasion from glass and carbon fillers. For corrosion-prone work or high-gloss medical parts, S136 stainless at 48–54 HRC is the alternative. Undercuts that need sliders add roughly $500 to $3,000 each. Tight tolerances and high-gloss finishes push it higher.

Piece price breaks the normal rules. With commodity plastics, material is an afterthought. With PEEK at $80–120/kg, material is the main event.

Treat these as starting points, not gospel. Real numbers ride on geometry, cavity count, and your supplier’s machine. A 5-gram medical part can cost more in resin than in machine time. That’s why your quote should always break out material separately.

One more number worth knowing. Break-even against CNC machining or 3D printing usually lands between 300 and 500 units. Below that, a mold may not pay for itself. Above it, injection molding pulls ahead fast. For a broader view of how tooling costs are built up, see our guide to mastering injection molding costs.

How to vet a China PEEK molder: the 7 checks

Ask seven questions. Listen for specific answers, not marketing.

1. Do you mold PEEK in-house, or job it out? A real molder owns the presses and runs PEEK themselves. Outsourcing quietly? You’ve added a layer with no accountability.

2. What machines and screws do you run PEEK on? You want high-temp machines with barrels rated above 400°C and wear-resistant or bimetallic screws. A good answer names the press make and the screw type. Vague answers — “we have many machines” — mean they’ve never done it.

3. How do you control mold temperature? They should mention holding the mold at 170–200°C for crystallization, usually with oil-based temperature controllers since water tops out around 90°C. No mention of mold heat or oil heaters? Walk.

4. Can you give me resin traceability? Ask for the Certificate of Analysis and lot numbers, usually from Victrex or Solvay. A genuine shop hands these over. A regrind reseller stalls.

5. How do you handle annealing and stress? Parts under load or sterilization need controlled cooling, sometimes a post-mold anneal to drive crystallinity to the design value. I’ve seen parts pass first inspection, then crack in the autoclave because nobody managed crystallinity. A molder who’s solved that will tell you how — usually a hold near 200°C followed by slow cool.

6. What certifications do you hold? ISO 9001 is the floor, not the bar. Medical needs ISO 13485. Aerospace needs AS9100. “ISO certified” with no number is a soft answer.

7. Who owns the mold, and will you release the drawings? Get it in writing. The mold is yours. So are the 3D files. Sort this before you pay, not after.

Save those seven. Paste them into your first email. The quality of the answers tells you more than any homepage. For a broader supplier evaluation framework, our guide to choosing the right injection molding manufacturer in China covers the full qualification process.

Verifying the resin is real

A 30% discount on PEEK almost always means the resin isn’t what you think. Genuine PEEK is too expensive for a real shop to undercut that hard.

Two common swaps. Regrind — reprocessed scrap blended into virgin resin. And a cheaper PAEK grade sold as PEEK. Both look identical in the bag. Both behave differently under heat and load.

Your defense is paperwork. Ask for the resin maker’s Certificate of Analysis, tied to a specific lot. Real Victrex or Solvay material names the grade and batch. Can’t produce it? Then you’re not buying what the quote says. For medical and aerospace work, demand lot traceability through the whole run — not just a sample at the start. Red flags to watch when sourcing from China covers additional warning signs beyond resin fraud.

Lead times, MOQ, and 2026 landed cost

Plan 2 to 4 weeks for a prototype tool. 6 to 8 weeks for a production mold and first articles. Simpler parts move faster. Tight tolerances and multi-cavity tools take longer.

Most decent shops run samples before full production. Insist on it. First-article approval on PEEK matters more than on a forgiving resin. The defects that kill PEEK parts often hide until the part sees real heat or load.

On cost, China still tends to land below US and European production, even after freight and duties. Often meaningfully so for mid-to-high volumes. But “tends to” isn’t “always.” Model your own landed cost — current tariffs, shipping, your volume — before you assume the savings. A cheap piece price can evaporate under a slow boat and a bad exchange week. For a full picture of what drives landed price, see our breakdown of MOQ and lead times in injection molding from China.

Design rules that keep your PEEK part moldable

A few design choices decide whether your part molds clean or fights you the whole run.

Walls. Keep them between 1 and 3 mm. Keep them uniform — variation across the part inside ±25% of nominal. PEEK holds structure at thin walls thanks to its modulus, but abrupt thickness changes invite differential shrinkage and warpage. Thicker sections also cool slower, and on a semi-crystalline resin that means uneven crystallinity from one zone to the next.

Draft. Plan draft angles by surface type, not as a single number. Standard external surfaces: 0.5–1°. Deep cavities and cores: 1–2°. Textured or etch-grained surfaces: 1–3° (the rule of thumb is roughly 1° of additional draft per 0.01 mm of grain depth). High-gloss surfaces: 0.25–0.5°. Rib sides: 0.5–1.5°. These principles align with the broader draft angle and wall thickness guidelines we cover for injection-molded parts.

Corners and ribs. Round your internal corners — minimum R ≥ 0.25–0.5× wall thickness. Sharp corners concentrate stress and crack under load, which matters more on PEEK than on most resins because it often replaces metal in load-bearing parts. For ribs: thickness at 40–60% of the wall (closer to 50% if you want to suppress sink marks), height no more than 2.5–3× wall, spacing at least 2× wall, root radius around 0.25–0.4× wall.

Shrinkage. Plan for it deliberately. Unfilled PEEK shrinks roughly 1.2–1.5% in the flow direction as it cools and crystallizes. Glass-filled grades cut that to roughly 0.3–0.6% in the flow direction, with higher shrinkage cross-flow — an anisotropy that becomes a warpage source if the mold isn’t designed around it. Carbon-filled grades drop in-flow shrinkage further still. This is one reason precision PEEK parts almost always use a filled grade: the tighter, more predictable shrinkage lets the toolmaker hit dimension. Your molder should design the cavity around the shrink number for your exact grade, not a generic figure.

Weld lines. Where two melt fronts meet, the bond is weaker than the parent material — in the worst case as low as 20% of base strength, in the best case 80%. Glass and carbon fibers don’t bridge a weld line, so filled grades are particularly affected. Gate placement and venting should keep weld lines out of any load-bearing area. Raise this with your molder — a good one will run a moldflow simulation and show you where the lines land before steel is cut.

You don’t need to out-engineer this. You need a supplier who raises these points before you do.

Tooling details that separate serious PEEK shops from bluffers

The tool is where corners get cut quietly. A few specifics worth asking about.

Steel selection. Cavity and core in H13 at 44–50 HRC for most PEEK work. S136 stainless at 48–54 HRC for medical, optical, or corrosive-environment parts. P20 pre-hardened steel at 28–32 HRC is too soft for production PEEK — it’ll wear through on filled grades and won’t hold tolerance at 200°C mold temp.

Cooling channels. With PEEK, you’re not “cooling” — you’re holding the mold at 170–200°C, usually with oil. The channel geometry still matters: typical diameters 8–14 mm, channel-to-channel center spacing roughly 2–3× the diameter, and channel center to cavity surface roughly 1.5–2× the diameter. Wider spacing or deeper channels leave hot and cold spots that show up as crystallinity variation across the part.

Venting. PEEK at 380°C melt is unforgiving of trapped gas — you’ll see burn marks and short shots in vent-starved corners. Vent depths of 0.02–0.05 mm, vent lands around 1.5 mm, and vents placed at the last-to-fill areas (typically opposite the gate, runner ends, and thin-wall convergence points). Ground vents, not milled.

Gate sizing. Filled PEEK shears badly through small gates. Glass-fiber grades typically need gate cross-sections about 10% larger than what you’d use for an unfilled engineering resin to keep shear rate down and preserve fiber length. Submarine gates on glass-filled PEEK are a known headache; edge or fan gates run cleaner.

None of these are exotic. They’re standard practice in any shop that runs high-temp engineering resin. The question is whether your supplier mentions them unprompted.

PEEK vs the alternatives: when it’s worth the price

PEEK earns its cost when nothing cheaper survives the environment. It runs continuously near 260°C, shrugs off most chemicals, and resists wear. It weighs about 70% less than the metal part it replaces, with no corrosion and no magnetic interference.

Strong case: jet-engine sensors, surgical instruments, semiconductor handling, downhole oil and gas parts. There, PEEK often beats metal outright.

But it’s not always the right call. Part never sees more than about 150°C? Not bathed in aggressive chemicals? A cheaper engineering resin like PPS, polysulfone (PSU), or a filled nylon may do the same job for a fraction of the resin cost. PPS in particular processes on similar (though slightly less extreme) equipment — barrel around 320–350°C, mold 120–160°C — at a fraction of the per-kilo price. I’ve talked buyers out of PEEK more than once. Paying $100 a kilo for thermal performance you’ll never use just burns margin.

The honest test: list the temperature, the chemicals, the load, and the lifetime your part must survive. A $10-a-kilo resin clears all four? PEEK is overkill. It can’t? PEEK is probably the cheapest part that actually works. For a structured way to evaluate resin choices before committing to a tool, a DFM review can catch material overkill early.

The Society of Plastics Engineers publishes technical papers comparing PEEK and competing high-performance resins across industries — a useful external benchmark when specifying materials for demanding environments.

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