CNC Machining & Injection Molding — DFM/Moldflow Support, CMM Inspection, Prototype to Production Solutions.
Custom Injection Molding Services
SPI develops the tooling, runs the molding process, inspects the agreed features, and supplies finished plastic parts for repeat production. Before tooling begins, our engineers review CAD data, resin, annual volume, cosmetic surfaces, assembly interfaces, and CTQ requirements to define a practical mold and production plan.
Recommended inputs: 3D CAD, 2D drawing, resin grade, annual quantity, tolerance requirements, cosmetic surfaces, assembly conditions, and inspection needs. NDA support is available.
Need the production mold shipped to your own plant or contract molder? Review our Export Mold Production service →
Injection molding is usually the right choice when the part design is stable, repeat demand can justify tooling, and the material and quality requirements can be defined before mold design begins. Reviewing these factors early helps prevent an unsuitable tooling investment, late part changes, and repeated corrections after T1.
Review wall thickness, draft, ribs, bosses, undercuts, parting line, gate position, ejection, and visible surfaces before committing to the mold structure.
Annual quantity and program life influence cavity count, mold steel, expected tool life, maintenance planning, unit cost, and the appropriate tooling route.
The selected resin affects shrinkage, warpage, drying, surface quality, tool wear, cooling strategy, and the practical molding window.
Critical-to-Quality features, cosmetic standards, inspection methods, FAI, CMM, and PPAP requirements should be identified before quotation and tooling approval.
SPI supports mold development, sampling, injection molding, inspection, and repeat plastic-part production. Final capability is reviewed against the part geometry, selected resin, mold structure, production demand, tolerance requirements, and customer approval scope.
Common project materials include ABS, PC, PC-ABS, PA, POM, PP, PE, TPU/TPE, PMMA, and PBT. PPS, PEEK, glass-filled, flame-retardant, and other high-performance grades require project-specific processing and equipment review.
Tooling routes can include rapid tooling, production molds, single-cavity and multi-cavity molds, family molds, insert molding, and overmolding. Steel, cavity layout, expected mold life, maintenance, and spare components are reviewed before tool design approval.
Production support can cover T1/T2 samples, design validation lots, low-volume bridge production, scheduled production runs, and repeat orders. Revision, resin, process, inspection, and cavity information can be controlled according to the agreed project plan.
A tolerance of ±0.05 mm may be feasible for selected molded features after review. Achievable control depends on resin shrinkage, geometry, wall thickness, datum strategy, mold design, process stability, cavity variation, and the agreed inspection method.
Required clamp force, shot size, mold dimensions, platen and tie-bar space, ejection, cooling, hot-runner connections, cycle target, and automation requirements are checked before a production route is confirmed.
Available records can include dimensional reports, FAI, CMM reports, material certificates, control plans, lot and cavity identification, traceability records, and PPAP or PPAP-style support when specified before quotation.
Send 3D CAD, the latest 2D drawing, resin grade, annual quantity, CTQ dimensions, surface requirements, and required quality documents. The tooling and T1 schedule will be confirmed after DFM, mold structure, steel, finish, and validation scope are reviewed.
Initial quotation target: within 24 hours after complete RFQ inputs are received.
We support cosmetic, structural, mechanical, and assembly-critical plastic components for OEM production. The examples below represent common part categories—not fixed material combinations. Final resin, tooling, tolerance, appearance, and inspection requirements are confirmed from the customer’s CAD and drawing.
Protective and cosmetic housings for instruments, sensors, controllers, automation equipment, and electronic assemblies.
Review focus: gate and weld-line visibility, sink around ribs and bosses, snap-fit stress, sealing gaps, and mating-part alignment.
Brackets, mounting frames, internal supports, installation bases, cable guides, and load-bearing plastic structures.
Review focus: rib-to-wall ratio, boss strength, glass-filled resin shrinkage, weld-line position, flatness, and CTQ datum strategy.
Gears, latches, hinges, cams, bushings, control features, and low-friction components used in repeat mechanical assemblies.
Review focus: tooth profile, bore size, roundness, resin shrinkage, gate stress, wear surfaces, and moving-feature clearance.
Connector housings, protective sleeves, threaded caps, fluid interfaces, gaskets, sealing features, and mating components.
Review focus: flash at shut-offs, core-pin deflection, terminal pitch, sealing surfaces, fit, flatness, and functional assembly.
Clips, wire-harness brackets, sensor housings, bezels, assembly frames, equipment covers, and functional production components.
Review focus: drawing revision, cavity identification, lot traceability, repeatability, material records, FAI, and PPAP scope when required.
Clear covers, light guides, display windows, instrument panels, cosmetic shells, sensor interfaces, and appearance-sensitive parts.
Review focus: flow marks, gate stress, venting, gloss, transparency, approved visual standards, handling, and dimensional inspection.
The purpose of a pre-tooling DFM review is to close avoidable design, material, mold, and inspection risks before they become steel changes. SPI reviews the available CAD, drawing, resin, production demand, cosmetic surfaces, assembly conditions, and CTQ requirements before releasing the tooling route.
Confirm resin, annual volume, operating temperature, chemical exposure, mechanical load, appearance requirements, mating parts, and customer approval expectations.
Decision: whether the project inputs are sufficient to begin tooling review.Review wall thickness, draft, ribs, bosses, screw posts, undercuts, shut-offs, snap fits, parting line, ejection, and visible surfaces.
Decision: part changes required before mold design release.Evaluate gate options, flow length, weld-line position, air traps, cooling access, resin shrinkage, fiber orientation, sink, and warpage-sensitive areas.
Decision: whether standard DFM is sufficient or Moldflow is recommended.Review cavity count, family-mold suitability, slides, lifters, inserts, overmolding, runner balance, steel choice, tool life, maintenance, and production demand.
Decision: the tooling structure suitable for cost, risk, and repeat production.Align drawing revision, datums, CTQ dimensions, measurement access, CMM or fixture requirements, visual standards, samples, and required quality documents.
Decision: how T1 samples and production parts will be inspected and approved.The exact output depends on project complexity and the agreed review scope. A pre-tooling review may include the following engineering decisions and records:
Send the available 3D CAD, 2D drawing, resin, annual volume, CTQ dimensions, surface requirements, mating conditions, and required inspection documents. Missing information will be identified before the tooling route is confirmed.
NDA support is available before CAD sharing.
Our workflow uses defined approval points before tooling, sample correction, and repeat production. The exact records and customer approvals depend on the project, but each stage should close the information needed before the next manufacturing decision begins.
Review the available CAD, 2D drawing, resin, annual volume, surface requirements, CTQ features, assembly conditions, and requested inspection records.
Customer checkpoint: Confirm drawing revision, project scope, quantity, material basis, and unresolved technical questions.
Typical project record: Quotation, stated assumptions, feasibility comments, and clarification list.
Review moldability, gate and parting-line options, draft, ribs, bosses, undercuts, ejection, cosmetic risks, CTQ requirements, and whether Moldflow is recommended.
Customer checkpoint: Close part-design questions and approve the proposed tooling route before design release.
Typical project record: Marked DFM comments, risk actions, tooling concept, and open-item list.
Finalize the agreed mold structure, steel, cavity layout, gate and runner, cooling, venting, ejection, slides, lifters, inserts, and maintenance considerations.
Customer checkpoint: Approve the agreed mold layout or design-release record and control later engineering changes.
Typical project record: Design approval record, manufacturing schedule, and controlled engineering-change notes.
Mold initial samples, review the actual tool condition, inspect agreed CTQ features, evaluate appearance and assembly fit, and define correction actions when required.
Customer checkpoint: Review samples, dimensional evidence, cosmetic findings, and the proposed correction list.
Typical project record: T1/T2 samples, trial evidence, inspection summary, and correction action status.
Confirm the approved part condition, molding parameters, inspection plan, cosmetic standard, material basis, packaging method, and quality documentation needed for production.
Customer checkpoint: Approve samples and the agreed production-release criteria before repeat manufacturing.
Typical project record: Sample approval, FAI or CMM data, material records, control plan, and PPAP support when specified.
Run the approved production process, perform agreed in-process and final inspections, control revisions and traceability, protect the parts, and arrange international delivery.
Customer checkpoint: Confirm receiving results, delivery performance, repeat-order demand, and any approved engineering changes.
Typical project record: Molded parts, inspection records, material or lot data, packing list, and shipment documents as agreed.
Injection molded parts should be approved using agreed inspection evidence—not appearance alone. The appropriate method depends on drawing tolerances, CTQ features, datum strategy, resin, cavity count, cosmetic requirements, assembly function, order volume, and the customer’s approval process.
Resin and production-lot controls are defined according to material sensitivity, appearance requirements, customer specifications, and traceability needs.
Initial samples should be evaluated against the latest drawing, agreed CTQs, cosmetic requirements, assembly conditions, and the actual mold revision being released.
The inspection method is selected according to part geometry, tolerance level, datum accessibility, measurement uncertainty, and the purpose of the approval.
After sample approval, production checks focus on maintaining the approved material, part condition, process window, appearance, CTQs, traceability, and packaging requirements.
These records are frequently used for sample or shipment approval, but the exact document set must still be confirmed in the quotation.
These items require additional planning, inspection time, sample quantity, process data, or customer-specific forms and should be defined before tooling or production approval.
Send the latest drawing, marked CTQ features, datum requirements, inspection method, material specification, sample quantity, and required customer forms. The quotation should include the inspection and document scope actually required for approval.
NDA review is available before proprietary CAD files and drawings are shared. Project files are used for quotation, engineering review, tooling, inspection, and order execution according to the agreed project scope and applicable confidentiality terms.
If your company requires a signed NDA first, confirm the agreement before uploading confidential CAD files, product specifications, customer-owned designs, or unreleased drawings.
Customer or SPI NDA terms can be reviewed before receiving proprietary 3D CAD, 2D drawings, specifications, and other confidential project information.
Project files are shared with the engineering, tooling, quality, commercial, or project personnel assigned to quotation and manufacturing execution as required.
Quotations, DFM comments, tooling changes, sample reviews, and inspection records should reference the applicable drawing or specification revision.
Sample approval, correction actions, CTQ requirements, and production release can be linked to the referenced drawing, sample, and customer decision status.
A reliable injection molding quote must define more than the mold price and unit price. Part geometry, resin, mold structure, cavity count, tool life, tolerances, appearance requirements, validation scope, order quantity, and delivery expectations all influence the final commercial plan.
Supplier quotations should be compared using the same tooling, sampling, correction, inspection, production, and delivery assumptions.
A lower tooling quote is not automatically a lower total project cost. Excluded correction work, additional sampling, missing inspection records, unstable cycle time, excessive scrap, or unclear maintenance responsibility can create higher cost after T1.
Complete inputs reduce quotation assumptions and make tooling cost, correction responsibility, inspection scope, and project timing easier to compare.
Initial quotation target: within 24 hours after complete RFQ inputs are received. Complex projects may require technical clarification first.
Review the detailed Injection Mold Cost Guide →Practical answers for OEM buyers reviewing injection molding cost, project timing, DFM requirements, molded tolerances, resin selection and quality documentation before tooling begins.
Cost depends on part geometry, resin grade, mold structure, cavity count, tool-life target, surface finish, tolerance scope, inspection requirements and production volume. For a meaningful quotation, provide 3D CAD, 2D drawings, resin, expected quantity, CTQ dimensions and the required approval documents.
Timing depends on design readiness, tooling complexity, resin and component availability, surface requirements, trial corrections and customer approval scope. The quotation should state whether the schedule ends at T1 samples, approved samples or first production delivery because these are different milestones.
Please provide 3D CAD, a revision-controlled 2D drawing, target resin, order quantity, annual volume, surface finish, cosmetic zones, CTQ dimensions, assembly requirements and required quality documents. STEP, IGES, X_T, Parasolid and PDF drawing formats are commonly accepted.
Yes. Before mold steel is cut, the engineering review can cover wall thickness, ribs, bosses, undercuts, draft, gate location, parting line, ejection, sink, weld-line and warpage risks, tolerance feasibility and inspection access. Any open assumptions should be resolved before final mold design approval.
Yes. The available route may include prototype validation, bridge production, low-volume manufacturing and scheduled repeat production. Tooling strategy is selected according to annual demand, resin behavior, part complexity, expected tool life, cavity strategy and inspection requirements.
Molded-part tolerance depends on resin shrinkage, feature size, wall uniformity, gate and cooling strategy, datum definition, conditioning state and process stability. We do not treat one tolerance value as a universal capability. Critical dimensions should be reviewed individually and linked to an agreed CMM, fixture or functional inspection method.
Common project materials include ABS, PC, PC-ABS, PA, POM, PP, PE, TPU, TPE, PMMA and PBT. Glass-filled, flame-retardant, high-temperature or wear-resistant grades such as PPS and PEEK require project-specific review of drying, processing temperature, shrinkage, mold wear and equipment compatibility.
Yes, when they are defined in the RFQ or quality plan. Depending on project scope, the release package may include FAI reports, CMM or dimensional reports, material certificates, control plans, cosmetic inspection records, deviation logs and PPAP-related documents. Customer forms, sample quantity and approval level should be confirmed before quotation.
Send your CAD files and production requirements for an engineering review of part manufacturability, tooling scope, material suitability, tolerance risk and inspection requirements before quotation.
Accepted engineering formats include STEP, STP, IGES, X_T, Parasolid and PDF drawings. Review scope and response timing depend on file completeness, part complexity and project requirements.