§ 01 / WHY

Why prototype tooling instead of 3D printing

3D printing is the default for small-quantity prototypes — cheaper, faster, no tooling to build. But for design validation, prototype injection tooling wins for three reasons:

Real material properties. Injection-molded ABS behaves like injection-molded ABS. A 3D-printed ABS-like resin behaves like photopolymer — UV sensitive, different shrinkage, different modulus. For functional validation, there is no substitute for the real material.

Real process physics. Wall sink, weld lines, flow marks, gate vestiges — these only show up in injection molding. You need real molded parts to discover which cosmetic issues will show up in production, so the production tool can be designed around them.

Real quantities. 50 prototype parts is expensive via 3D printing ($30-100/part) and fast to mold ($8-20/part after tooling). If you need to send samples to multiple customers, distributors, and test labs, molded parts are economic.

When to skip prototype tooling

If your design is final and production volume justifies it immediately, go straight to a production tool — saves weeks. Prototype tooling makes sense when you need design iteration (1-3 tool modifications) before committing to production.

§ 02 / WHAT

What "prototype tooling" includes

ElementPrototype tool (P20)Production tool (H13)
Tool steelP20 (32 HRC)H13 (52 HRC) or S136
Cavity count12, 4, 8, 16, 24+
Cooling channelsBasic straight-drilledConformal, optimized
Surface finishSPI B1 (mild polish)A1-D3 range or textured
Runner systemCold runnerHot runner typical
EjectionPin ejection onlyPins, lifters, slides, cores
Shot life10,0001,000,000+
Cost$2,800–$8,000$8,500–$50,000+
Lead time14–21 days35–49 days
§ 03 / THE

The prototype tooling workflow

01

DFM review (1-2 days)

We review your CAD for draft angles, wall thickness uniformity, undercuts, and sink-prone ribs. You receive a marked-up DFM report after quote acceptance.

02

Tool design (3-5 days)

Tool designers create the mold assembly, parting line layout, gate location, and cooling plan. You review and approve before steel is cut.

03

Steel cutting (7-10 days)

CNC roughing, finish machining, EDM for tight pockets, and polishing. Quality checks throughout.

04

Tool trial (T1)

First shots are produced. We capture dimensional data, cosmetic photos, and weld-line locations. Ship 10-20 samples to you for review.

05

Tool revisions (if needed)

Two revisions typically included in quote. Revisions beyond two charged per change. Common revisions: shimming for gap adjustments, ejection timing tweaks, venting adjustments.

06

First Article production

On approved tool, we can run your first production batch (typically 500-5,000 units) within a week of T1 approval.

§ 04 / RESINS

Resins compatible with prototype tooling

Prototype tooling handles most common thermoplastics. Some demanding resins require production-grade tooling:

ResinPrototype OK?Notes
ABS✓ YesMost common prototype resin
PP (polypropylene)✓ YesLow shrinkage, forgiving
PC (polycarbonate)✓ YesHigher melt temp, needs good venting
PC/ABS✓ YesStandard engineering blend
HDPE / LDPE✓ YesLow cost, straight-pull geometries
Nylon (PA6, PA66)✓ Yes, unfilledGlass-filled wears P20 faster — may only last 2,000-5,000 shots
TPE / TPU✓ YesSoft resins, long cycles — prototype tool fine
PA66-GF30 (glass-filled)⚠ LimitedAbrasive — P20 tool life drops to ~2,000 shots
PEEK✗ NoNeeds hardened tool (H13 or above) due to 360 °C melt temp
LSR silicone✗ NoRequires specialized LSR tooling
LCP (liquid crystal polymer)✗ NoExtremely abrasive, hardened tool only
§ 05 / TYPICAL

Typical pricing ranges

Prototype tool cost depends mostly on part size and complexity. Rough guide:

Part complexityPart envelopeTypical tool costPiece price (ABS)
Simple (flat, single draft)< 50 × 50 × 20 mm$2,800–$3,800$0.80–$1.50
Moderate (ribs, bosses)< 100 × 100 × 40 mm$3,800–$5,500$1.50–$3.00
Complex (undercuts, actions)< 200 × 150 × 80 mm$5,500–$8,000$3.00–$6.00
Large or multi-action> 200 × 150 × 80 mmQuote requiredQuote required
Why tooling in China costs ~40% less

Dongguan is the global center for plastic tooling. Skilled tool makers, domestic tool steel, and mature hot-runner supply chain make prototype tools 40-60% cheaper than comparable US/EU quotes. Quality is comparable — we use the same CAD/CAM software and tool steel grades.

§ 06 / FAQ

FAQ

Who owns the tool after it's built?
You do. We store the tool at our facility at no charge for the first year, then $25/month after. You can request tool transfer at any time — to yourself, to a third party, or to another fobproto facility. Tool transfer is a 5-day process including re-certification at the receiving facility.
How do design revisions work?
Two tool revisions are typically included in prototype tooling quotes. Revisions after two are charged per change: adding metal (drilling a new hole, etc.) is $250-800; welding-up and re-cutting (filling a pocket) is $800-2,500; adding a mechanism (lifter, slide) is $2,000-6,000. We quote each revision individually.
Can you provide mold flow analysis?
For tools below $5,000, we skip simulation and rely on DFM experience. For tools above $5,000 or parts with flow challenges (thin walls, long flow paths, sensitive cosmetics), we run Moldflow simulation for $200-400 added cost. Results include fill time, cooling time, warp prediction, and weld line locations.
What if my design changes significantly after tool is built?
For significant changes, we recommend rebuilding rather than modifying — added metal rarely blends perfectly with original steel. We offer a 30% discount on new prototype tools when you retire an existing fobproto prototype tool. For minor changes, revisions handle it.
Can you ship prototype tools internationally?
Yes. Prototype tools are typically 50-200 kg. DDP shipping to US is $400-1,200 depending on size. Sea freight 20-30 days, air 7-10 days. We handle export customs and duties. For tools remaining at fobproto for your production, no shipping needed.
READY WHEN YOU ARE

Ready to validate your design in real plastic?

Upload STEP and target material. DFM feedback included with every quote. First parts typically in 3 weeks.

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