Use SPI guides to find the right reference before design review, material selection, process comparison or RFQ preparation.

Manufacturing Guide Library

Manufacturing Guides for Engineers and Sourcing Teams

Use this guide library to find the right practical reference for a manufacturing decision, whether you are reviewing part design, selecting a material, comparing production routes, or preparing an RFQ.

Each guide focuses on a defined engineering task. This Hub helps you choose the right starting point; the detailed design rules, validation methods, cost criteria and process limits remain on the dedicated guide pages. For deeper project-stage engineering review, SPI maintains a separate Technical Articles resource path.

Start by Task Design, materials, cost, RFQ preparation or process comparison.

Choose the Guide Open the dedicated reference that matches the decision you need to make.

Go Deeper When Needed Use Technical Articles for deeper validation, tooling or production analysis.

Injection molding guides should be selected by the engineering decision that needs to be made next.

Injection Molding Guides

Start with the Injection Molding Guide That Matches Your Next Decision

Use these guides when injection molding is already a likely manufacturing route. Start with the fundamentals if the process is new to the project, move to the design guide when geometry needs DFM review, or use the checklist when drawings and requirements are being prepared for quotation or tooling release. Material selection, mold steel and process comparisons are handled in separate Guide Hub sections.

Start Here

Injection Molding Basics

Use this guide to understand the molding process, tooling relationship and basic production considerations before moving into detailed DFM.

Open the basics guide Design Review

Injection Molding Design

Use this guide when wall thickness, draft, ribs, undercuts and other part-design features need manufacturability review before tooling.

Open the design guide RFQ / Release

Injection Molding Checklists

Use these checklists to verify that drawing data, CTQs, material, volume and approval requirements are ready for engineering review.

Open the checklists

Use the tooling-stage resources when mold material, release evidence or acceptance criteria become the next engineering decision.

Mold Design & Validation Guides

Review Mold Decisions Before Tool Release and Production Approval

Use these resources after the molded-part geometry has moved beyond basic DFM and the project needs decisions around tooling material, mold condition, validation evidence or release criteria. Start with mold steel when tooling durability and surface requirements are still open; use validation guidance when trial evidence and approval stages must be defined; use acceptance criteria when the question is what must pass before release.

Tooling Material

Mold Steel & Surface Treatment

Use this guide when mold steel, hardness, wear resistance or tooling surface treatment must be selected before the mold specification is fixed.

Open the mold steel guide Validation

Injection Mold Validation

Use this resource when trial stages, inspection evidence and approval logic must be organized before a mold moves toward production release.

Open the validation guide Release Criteria

Injection Molding Acceptance Criteria

Use this checklist when dimensional, cosmetic, functional and documentation requirements must be defined as pass-or-hold criteria.

Open the acceptance checklist

Select the material guide that matches the manufacturing route and the property or finish decision still open in the project.

Materials Guides

Find the Right Material Guide for the Manufacturing Route

Use this section when material or surface requirements are still open. Start with the general materials guide when the project spans metals and plastics; move to the molding or additive guides when the manufacturing route is already defined. Use the finishing guide when the remaining question concerns appearance, corrosion protection or post-process requirements rather than the base material itself. Mold steel remains a tooling decision and is handled separately.

General Selection

Manufacturing Materials

Use this guide when comparing common metals and plastics across machining, molding and other manufacturing routes before material selection is fixed.

Open the materials guide Thermoplastics

Injection Molding Materials

Use this guide when the molding route is fixed and resin selection must be narrowed by stiffness, temperature, wear, chemical or application requirements.

Open the molding materials guide Additive Materials

3D Printing Materials

Use this guide when additive manufacturing is being considered for prototypes or functional parts and the material must match the test objective.

Open the 3D printing materials guide Finish Selection

Surface Finishing

Use this guide when appearance, corrosion resistance, texture, wear protection or downstream finish compatibility drives the remaining specification.

Open the finishing guide

Cost review and RFQ preparation are different tasks: first understand what changes the quotation, then make sure suppliers receive the same inputs.

Cost & RFQ Guides

Prepare a Comparable Quote Before You Compare Supplier Prices

Use these resources when the project is moving toward quotation. Start with the cost guide when you need to understand why tooling prices, lead times or included approval scope differ between suppliers. Use the RFQ checklist when the next task is making sure CAD, drawing, material, volume, CTQs and required evidence are defined before price comparison. Process-selection comparisons remain in a separate section.

Cost & Quote Scope

Injection Mold Cost Guide

Use this guide when tooling price, cavity strategy, steel, trial scope or lead-time assumptions must be normalized before comparing supplier quotes.

Open the cost guide RFQ Preparation

Injection Mold RFQ Checklist

Use this checklist when CAD, drawing revision, resin, quantity, CTQs, appearance and approval requirements must be complete before requesting a quote.

Open the RFQ checklist

CNC & Manufacturing Guides

Use the Manufacturing Guide That Matches the Part-Making Route

Use these guides when the manufacturing route is already known and the next question is how to make the part easier to produce. Choose the CNC guide for machined geometry and tool-access review, the sheet-metal guide for bend and fabrication constraints, or the vacuum-casting guide for wall transitions, release-sensitive geometry, CTQ features and cosmetic planning in low-volume urethane parts. Process-to-process decisions are handled separately in the comparison section.

CNC Machining

CNC Design Guidelines

Use this guide when tool access, internal radii, pockets, holes, tolerances and other machined features need manufacturability review.

Open the CNC design guide Sheet Metal

Sheet Metal Design

Use this guide when bend geometry, hole placement, flange dimensions and fabrication limits must be reviewed before drawing release.

Open the sheet metal guide Vacuum Casting

Vacuum Casting Design Guide

Use this guide after vacuum casting is selected to review wall transitions, draft, ribs, bosses, undercuts, inserts, CTQ features, cosmetic surfaces and silicone-mold release risk before drawing release.

Open the vacuum casting design guide

Process Comparison Guides

Compare Manufacturing Routes Before You Lock the Process

Use these guides when the manufacturing route is still open. Choose the comparison that matches the unresolved decision: machining versus molding, bridge production versus hard tooling, rapid versus production tooling, or 3-axis versus 5-axis CNC. Each guide focuses on the trade-offs that influence process fit before design, tooling or quotation assumptions are finalized. Once the route is selected, return to the dedicated design or material guide for that process.

Process Choice

Injection Molding vs CNC Machining

Use this guide when production volume, tooling investment, geometry, tolerance or unit-cost structure determines whether molding or machining is the better route.

Compare molding and CNC Bridge Production

Vacuum Casting vs Injection Molding

Use this guide when low-volume bridge production, prototype appearance, tooling commitment and production-material requirements must be balanced.

Compare casting and molding Tooling Strategy

Rapid Tooling vs Production Mold

Use this guide when launch speed, expected tool life, production volume and validation needs determine whether bridge tooling or a production mold is appropriate.

Compare tooling strategies CNC Route

5-Axis CNC vs 3-Axis CNC

Use this guide when multi-sided geometry, setup reduction, feature access and machining complexity determine whether 5-axis capability adds value.

Compare CNC approaches

Deeper Engineering Resources

Need More Than a Practical Guide?

Use the Guides Hub for practical design, material, process-selection and RFQ references. When the project moves into deeper engineering questions—such as validation evidence, CTQ control, tooling decisions, defect analysis or production stability—continue to the Technical Articles Hub. That resource is organized for project-stage engineering review rather than basic guide discovery.

Use Technical Articles For

Validation & approval
CTQ & tolerance control
Tooling engineering
Defect analysis
Quality evidence
Production stability

Browse Technical Articles

Ready for Engineering Review?

Turn the Guide Decision Into a Part-Specific DFM Review

If the likely process, material direction or main design risk is already identified, send the latest CAD and drawing for a part-specific engineering review. SPI can review manufacturability, critical requirements and open assumptions before quotation or tooling decisions are finalized.

STEP, IGES and PDF drawings can be submitted with material, tolerance, finish, volume and inspection requirements where available.