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INJECTION MOLDING COMPONENTS

Injection Molding Screw & Barrel

Stable molding starts in the plasticizing unit. YINGDA matches the screw and barrel to your machine, resin and shot requirements, then confirms material and surface treatment against the expected wear conditions.

Replacement components can be reviewed from a machine model, drawing, sample, clear photos or measured dimensions. Options cover general-purpose resins, engineering plastics and filled compounds. Injection molding screws and barrels are available individually or as matched sets, according to your machine and replacement requirements.

Machine matched

Drawing or sample

HV900–1000

Nitrided hardness

0.5–0.8 mm

Nitriding depth

Steel, treatment, dimensions and inspection criteria are agreed for each order before manufacturing.

Explore: Applications  ·  BM1 & BM2 Wear Technologies  ·  Custom Design & OEM
Technical guide: How to choose A, B and C injection molding screws

PRODUCT OVERVIEW

A better match for the plasticizing unit

The screw conveys, melts and mixes resin while the barrel provides the working bore. Together they prepare a consistent melt and measured shot before injection into the mold.

A replacement should match more than diameter. YINGDA reviews the injection machine, screw profile, L/D, shot requirement, resin, filler content and existing wear before proposing construction.

If the original drawing is unavailable, machine details, photos and a worn component can start the review. We identify which measurements still need confirmation before production.

WHERE IT WORKS

Where injection screws and barrels are used

The selected steel, geometry and treatment depend on the resin and operating conditions. Typical plasticizing duties include:

PP & PE molding

ABS components

PC & PA parts

Glass-filled resins

Recycled compounds

General molding units

APPLICATION SUPPORT

Problems worth checking before replacement

A worn component may be only part of the cause. Material condition, temperature, back pressure and machine settings should also be checked.

Shot size varies

Screw and barrel wear, the check ring and back-pressure settings can affect shot repeatability.

Melt quality is uneven

Screw geometry, residence time, resin condition or process temperature may be involved.

Black specks appear

Stagnant material and overheating can cause degradation; inspect the working surfaces and process settings.

Filled resin causes fast wear

Glass fiber and mineral fillers raise abrasion, making steel and surface selection more important.

Part dimensions are unknown

A machine model, sample, photos and key measurements can establish a practical review path.

PLASTICIZING BASICS

How the screw and barrel affect each shot

During recovery, screw rotation conveys and plasticizes resin while melt accumulates ahead of the screw. Geometry and working clearance influence mixing, recovery time and melt consistency.

During injection, the front-end non-return assembly helps limit backflow so the prepared melt can be delivered toward the mold. Its fit should be considered alongside the screw and barrel.

A replacement should therefore be reviewed as a working assembly: screw, barrel and front-end parts. A worn check ring or mismatched bore can affect shot consistency even when the new screw material is correct.

TECHNICAL RANGE

Full technical specifications

The values below are available specifications and options. The approved drawing and order define where each material, treatment and acceptance value applies.

PARAMETER

VALUE / OPTION

Product type

Screw and barrel for injection molding machines

Machine

Injection molding plasticizing unit; connection dimensions confirmed per model

Processed resins

PP, PE, ABS, PC, PA, recycled and filled compounds, subject to formulation

Available steels & alloys

38CrMoAlA, SKD61, Cr12MoV, SACM645, nickel-based alloys and GH113

Nitriding hardness

HV900–1000, where specified

Nitriding depth

0.5–0.8 mm, where specified

Quenching hardness

HRC55–62, where applicable

Nitriding brittleness

≤ Grade 2, where specified

Surface roughness

Ra0.4, where specified

Screw straightness

0.015 mm, where specified

Chrome hardness

≥950 HV, where plating is specified

Chrome layer

0.05–0.10 mm, where applicable

Alloy layer depth

0.8–2.0 mm, where applicable

Machine matching

Model, drawing, sample, photos or measured dimensions

Design inputs

Resin, filler content, screw diameter, L/D, shot requirement and wear

Treatment options

Nitriding, hard chrome plating, bimetallic layer and alloy spray welding

Customization

Geometry, material and surface treatment to the approved order

Acceptance

Final dimensions and specified surface values confirmed before production

Final dimensions, steel, treatment and inspection requirements are confirmed against the injection machine and processed resin before production.

Injection Screw Diameter & PS Shot Weight Reference

The table below compares A, B and C screw options for selected Haitian Mars V machines. For example, MA1600V/570 lists 40 mm / 229 g, 45 mm / 290 g and 50 mm / 359 g. Weights use polystyrene (PS); values vary by machine and material.

Haitian Mars V machine examples: A, B and C screw diameters and PS injection weights. See accompanying text and source for details.

Open the chart at full size · Source: Haitian Mars V technical catalogue (2023-10-25), pp. 2–4
Reference only. Check the machine model, screw diameter, length, barrel dimensions and drive connection against the drawing or existing parts before ordering. The catalogue does not provide screw or barrel lengths in this chart.

General Injection Screw & Barrel Size Reference

Use this chart to compare approximate shot weights with screw diameter and length, and barrel outside diameter and length. For a replacement that fits your machine, please share your machine model, drawing or measurements of the existing parts.

General injection molding reference chart with shot weight, screw diameter and length, and barrel outside diameter and length. Confirm actual dimensions before ordering.

View full-size chart
Dimensions are for reference. We confirm the final specifications and connections with you before manufacturing.

CHOOSE FOR THE RESIN

Steel and surface options

General resins and abrasive compounds place different demands on the working surfaces. YINGDA selects a construction for the machine and material rather than treating one steel as universal.

MATERIAL OPTIONS

38CrMoAlA nitrided steel

A common base choice for screw and barrel components. Specified nitriding can reach HV900–1000, 0.5–0.8 mm depth and brittleness no higher than Grade 2.

SKD61 & Cr12MoV tool steels

Tool-steel options are reviewed for the component design, processing temperature, wear pattern and required heat treatment.

SACM645 & special alloys

SACM645, nickel-based alloys and GH113 are available for applications that call for a different nitriding, wear, corrosion or heat-resistance approach.

SURFACE & WEAR OPTIONS

Nitriding

A hardened working surface with specified hardness, depth and surface finish. The approved order defines the acceptance values.

Hard chrome plating

An option where the component and resin call for it. Available catalog values include hardness of at least 950 HV and 0.05–0.10 mm layer thickness.

Bimetallic or spray-welded alloy

An alloy working layer may be considered for abrasive or demanding compounds. The application area and 0.8–2.0 mm layer depth are confirmed per design.

Inspection follows the agreed drawing

YINGDA confirms critical dimensions, straightness, surface finish and specified hardness against the approved drawing and order before acceptance.

MADE TO FIT

Built for your injection machine

The replacement is designed around the plasticizing unit, resin and shot requirement. Drawings are helpful; a machine model and measured sample can also start technical review.

Machine interface

Screw diameter, barrel bore, L/D, mounting and connection dimensions.

Screw profile

Conveying, compression and mixing geometry reviewed for the resin and required shot.

Steel & treatment

38CrMoAlA, tool steels, nitriding, chrome plating or alloy options as specified.

Front-end fit

Screw tip, check ring and related front-end interfaces checked against the unit.

Replacement from a sample

Machine data, photos and measured wear parts used to confirm missing drawing details.

FOR A USEFUL QUOTATION

What helps us quote accurately

Send what you have now. We can identify any missing measurements during the technical review.

01 Injection machine model and plasticizing unit

02 Screw diameter, barrel size and L/D if known

03 Resin grade, glass fiber or other filler content

04 Shot requirement and current molding issue

05 Existing wear, surface damage or leakage symptoms

06 Drawing, photos, measurements or worn sample

Send Drawings for Review

THE YINGDA COMMITMENT

Agree the specification before machining

Engineering review

We connect resin, shot requirement and current wear to a practical screw and barrel specification.

Inspection to agreed criteria

Critical dimensions and surface values are checked to the drawing and order requirements.

1-Year After-Sales Quality Assurance

We provide one year of after-sales quality assurance. See the coverage details below.

Quality Assurance Coverage

Period: Our one-year after-sales quality assurance begins on the date the screw and barrel are formally put into normal use; shipping time is not counted.

Covered issues: Under normal operating conditions, it covers product quality issues including abnormal wear, screw breakage, and failure to reach the agreed output when first put into operation.

Free replacement: For a covered product quality issue, YINGDA provides a new replacement product at no charge.

Coverage limits: Gradual output decline caused by normal wear over time is not a product quality issue. Human-caused breakage and damage from foreign objects are excluded.

COMMON QUESTIONS

Injection molding screw barrel FAQ

What should be matched besides screw diameter?

The machine connection, barrel bore, L/D, screw profile, shot requirement and front-end fit all matter. Resin and wear conditions guide the steel and treatment choice.

Can we start from a worn screw without its original drawing?

Yes. Send the machine model, photos, a sample and any measured dimensions. YINGDA will identify the missing details that need confirmation before manufacturing.

What changes when molding glass-filled PC or PA?

Filler content, process temperature and expected wear need review. Geometry and a suitable steel or alloy working surface are selected against those conditions.

When should an alloy layer be considered?

Highly abrasive or filled compounds may justify a bimetallic layer or alloy spray welding. We compare those options with nitrided steel for the actual material and duty.

Which resins can these components process?

Projects can be reviewed for PP, PE, ABS, PC, PA, recycled resins and filled compounds. Final construction follows the formulation and machine conditions.

Can hard chrome plating be specified?

Yes, where suitable for the component and material. The approved order defines the plated area, thickness and hardness requirements.

How are the final tolerances agreed?

Critical dimensions, straightness, roughness and treatment values are written into the approved drawing or order before production and inspection.

What is enough information for an initial quote?

A machine model, resin, part photos and the problem you want to solve are enough to begin. A drawing, sample and measurements help us confirm the final specification.

WORK WITH YINGDA

Let's Build Around Your Process.

Share your drawing, sample or machine details. We will review the fit, materials and working conditions, then discuss screw and barrel options that make sense for your production and budget.

✓ Direct factory communication

✓ Engineering-reviewed specifications

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