Ningbo Zhaoxu Plastic Products Co., Ltd. undertakes mold development and injection overmolding processing for five-star handles, plastic plum blossom handles and copper nut insert overmolded parts. We support mold development from drawings, 3D scanning & reverse engineering from samples and insert pre-embedding injection production. Integrating plastic mold R&D, insert injection molding and supporting post-processing, we provide one-stop services including product DFM evaluation, mold manufacturing and mass injection molding for manufacturers of machinery equipment, instrument frames, jigs & fixtures, medical devices and automation equipment.

      The five-star handle is an injection molded part with pre-embedded copper nut inserts. Copper nuts are pre-placed into the mold and encapsulated by plastic. It serves as a manual locking and adjusting component for equipment. Key requirements include firm embedded copper nuts without slipping, comfortable hand feel of five-star profile, high strength at the handle root to resist cracking under tightening torque, plastic free of sink marks and short shots, good concentricity of nuts and stable thread precision. We can complete mold design, mold trial and mass production according to customers’ 3D drawings or physical samples.

      The factory is located in Fanci Mold City, Longshan, Cixi, Ningbo, covering an area of 2000㎡ with independent mold workshop and injection molding workshop. The mold workshop is equipped with complete processing equipment including CNC machining centers, high-speed engraving and milling machines, EDM machines and grinders. Haitian injection molding machines equipped with servo manipulators are deployed in the injection workshop for stable mass production of plastic parts with pre-embedded inserts.

Product Processing Advantages

      1. Integrated mold opening and injection molding. Product structure evaluation, mold machining, mold trial & revision and insert pre-embedding injection production are all completed in-house, reducing outsourced processes and facilitating lead time control and product consistency.

      2. Pre-project DFM manufacturability analysis. Risk prediction for five-star rib structure, positioning of pre-embedded copper nuts and torque bearing capacity. Optimize positioning structure to prevent nut offset, rotational slipping and rib fracture during injection molding.

      3. Multiple grades of engineering plastics available. PP, PA Nylon, ABS and glass fiber reinforced materials are optional. Black natural color can be directly molded to meet equipment requirements of anti-twist locking, wear resistance and aging resistance.

      4. Precision mold design for insert embedding. Built-in copper nut positioning structure inside the mold ensures good concentricity of copper nuts, protects threads from high injection temperature damage, uniform dimension of five-star contour and even stress distribution during tightening.

      5. Sound quality control system. Material certificates can be provided for both raw plastics and copper inserts. First article confirmation, torque sampling inspection, in-process patrol inspection and thread go/no-go gauge testing are implemented with traceable production batches.

      6. Supporting post-process services, including burr trimming, thread inspection, appearance sorting and packaged delivery to reduce customers’ workload of secondary processing.

Applicable Product Categories

      Insert injection molding for five-star & plum blossom handles

      Injection molding of plastic adjusting handwheels over copper nuts

      Plastic structural parts for equipment locking knobs

      Five-star handles for jigs and fixtures

      Molded parts with pre-embedded copper nut inserts

      Custom various special-shaped handles and adjusting knobs

      For other plastic parts with pre-embedded inserts, mold opening feasibility can be evaluated with drawings or samples.

Common Material Guide

      ABS: Good molded appearance, nice toughness and moderate cost, preferred for light-load adjusting handles.

      PA Nylon (glass fiber reinforced): High strength, torque resistance and wear resistance, suitable for heavy-duty locking five-star handles for mechanical equipment.

      PP: Good toughness and impact resistance, suitable for low-load, low-cost adjusting knobs.

      Material selection is comprehensively determined by tightening torque, application scenario, heat resistance and cost. Engineers provide material selection suggestions.

Processing Workflow

      Customer provides 3D drawings / physical samples → DFM product structure evaluation → Proposal and quotation issued for mutual confirmation → Mold structural design (including insert positioning mechanism) → Mold CNC/EDM machining, polishing and mold fitting → T1 mold trial → Samples sent to customer for confirmation → Mold revision and adjustment based on feedback → Mass insert injection molding after sample approval → Thread / torque inspection → Product packaging & delivery → After-sales follow-up.

      During requirement evaluation, customers provide drawings or physical samples and specify torque requirements, materials and annual output. Quotation will be available within 1‑2 working days.

      Mold design focuses on five-star ribs and pre-embedded copper nut positioning structure to prevent copper insert displacement during injection molding.

      Mold trial inspects appearance, thread go/no-go and handle torque strength. Mass production will be launched after customer approval.

Quality Control

      Specifications of raw plastics and copper inserts are checked upon warehousing; material certificates are available.

      Dimension verification in each mold machining procedure, focusing on insert positioning and profile tolerances.

      First article inspection is implemented for injection production, with regular in-process patrol inspection. Sampling torque test and thread go/no-go gauge test are carried out to monitor defects such as insert offset and plastic cracking.

      Finished products are mainly inspected on appearance, threads and handle strength; defective products are sorted and isolated.

      Production records include machine number and raw material batch to realize batch traceability.

Factory Profile

      The factory covers approximately 2000 square meters with separate workshops for mold, injection molding and assembly.

      The mold workshop is equipped with more than ten complete sets of equipment including CNC machining centers, high-speed engraving and milling machines, EDM machines and grinders.

      Injection molding equipment are Haitian injection machines equipped with servo manipulators and production monitoring systems for stable pre-embedded insert injection molding.

      The core engineers have 25 years of plastic molding experience and 15 years of auto parts quality control experience, with supporting service experience for OEM manufacturers.

      The factory is located in Fanci Mold City, Longshan Town, Cixi, Ningbo, close to National Highway 329 with convenient logistics and transportation.

Cooperation Steps

      1. Inquiry & Communication: Provide 3D drawings or physical samples and specify annual output, torque and material requirements. Response and communication within 1 working day.

      2. Solution Evaluation: Engineers complete product assessment and issue quotations for molds and injection molded products within 1‑2 working days.

      3. Quotation Confirmation: Confirm mold steel, plastic materials, insert supply, lead time and cooperation terms.

      4. Mold Development: Complete structural design, machining, assembly, mold trial and revision. Lead time depends on product complexity.

      5. Sample Confirmation: Deliver trial samples for customers to check profile, threads and locking torque and complete mold acceptance.

      6. Mass Production: Carry out pre-embedded insert injection production according to orders and deliver goods after inspection and packaging.

FAQ

Q: Can you develop molds if I only have physical samples of five-star handles without drawings?

A: Yes. We support 3D scanning and reverse engineering from samples to generate 3D models for mold development.

Q: Will copper nuts slip and rotate after injection overmolding?

A: Special positioning structure is adopted in mold design, and copper nuts are knurled. Firm interlocking is achieved after overmolding, so no slipping under normal torque.

Q: How much tightening force can the handle withstand?

A: It is customized according to product size and material selection. Glass fiber reinforced nylon version can bear larger torque. Please communicate working condition requirements in advance.

Q: Does insert injection molding for five-star handles support small-batch trial production?

A: After mold acceptance, both small trial orders and large-volume orders are acceptable.

Q: Will samples be provided for confirmation before mass production?

A: Yes. Samples will be provided after mold trial. Mass production will start only after customer approves appearance, threads and torque strength.

Contact Information

      Company Name: Ningbo Zhaoxu Plastic Products Co., Ltd.

      Factory Address: No.5 Weisan Road, Fanci, Longshan Town, Cixi City, Ningbo, Zhejiang Province

      Business Scope: Insert injection molding for five-star handles, plum blossom adjusting handwheel overmolded parts, plastic structural parts with pre-embedded copper nuts, precision injection molds, custom manufacturing from samples & drawings

      1688 Store: https://chaoxusuliao.1688.com