Matched conical screws, hardened and polished. Machined in our own Henan workshop — to your drawing, or reverse-engineered from your worn parts.
Conical screws must be a pair: same taper, same flight profile, same timing. We machine both in one set-up, hardface the flight lands, polish the channels and match-mark them so they go back in the same position.
Supplied to your barrel dimensions — send bore measurements or the barrel itself for the best fit.
Quote within one business day. We reply with a matching proposal, delivery date and price — no generic catalogue PDF.
Standard range shown. Every dimension below can be changed to your machine, resin and output — custom manufacturing is our daily business.
| Supplied as | Matched, match-marked pair |
|---|---|
| Models | 51/105 to 110/220 and custom |
| Material | 38CrMoAlA / 42CrMo |
| Treatment | Gas nitrided + hardfaced flight lands |
| Finish | Polished channels |
| Clearance | Set to your measured bore |
| Lead time | 30–40 days |
The honest answer depends on your resin, not on price. Here is how we advise customers.
| Gas Nitrided (38CrMoAlA) | Bimetallic Alloy Lining | |
|---|---|---|
| Best for | Unfilled PE, PP, PS, ABS, virgin PVC | Glass-filled, mineral-filled, recycled, corrosive |
| Surface hardness | HV 900–1020, depth 0.45–0.7 mm | Alloy layer 2–5 mm, metallurgically bonded |
| Typical service life | Baseline | 3–5× baseline on abrasive resin |
| Cost | Lower | Higher, recovered through fewer stoppages |
| Certification | MTC with heat number | MTC + hardness records, third-party on request |
Yes for conical twins — one new screw against one worn one gives uneven plasticising and unstable output.
Yes. Send bore measurements at several points along the taper, or the barrel itself.
Nitrided standard; hardfaced lands for filled or recycled PVC. We recommend based on your compound.

Matched screw and barrel for SJSZ 51/105 conical twin extruders.
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Large-format conical twin set for big-diameter PVC pipe lines.
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Send your machine model, drawing or worn sample — we reply with a matching proposal and quotation within one business day.