Injection Molding Tooling
The tool is the largest one time cost in an injection molding program, and it fixes your cycle time, part cosmetics and achievable tolerance for the life of the part. This page covers the tooling routes, what actually moves the price, and how long each route takes.
Injection Molding Tooling
Most programs do not need production steel on day one. Picking the route that matches your current volume and design maturity is the single biggest lever on both cost and schedule.
Aluminum or pre hardened steel cut for first articles and fit checks. First parts in about two to three weeks, at a fraction of production tool cost, with the trade off that the tool is not built to run for years.
Upload CAD for a tooling quoteCovers demand between the first shipments and the production tool. Useful when the design is still settling or when a launch date will not wait for hardened steel.
Hardened tool steel built for hundreds of thousands of cycles, with the cooling, ejection and wear packages needed to hold cycle time and dimensions over the life of the part.
High volume injection moldingSeveral different but related parts cut into one tool. Lowers total tool count for part sets that share resin, shrink and process window, and that are ordered together.
Family injection moldingChoosing tool steel
Tool material sets tool life, lead time and how well the tool tolerates abrasive or corrosive resins. Glass filled resins and PVC are the two cases where going cheaper on steel usually costs more later.
| Tool material | Typical tool life | Lead time | Best fit |
|---|---|---|---|
| Aluminum (7075) | 1,000 to 10,000 shots | 2 to 3 weeks | Prototypes, fit checks and very low volume runs |
| Pre hardened steel (P20, 1.2311) | 100,000 to 500,000 shots | 3 to 5 weeks | Bridge and mid volume work in most unfilled engineering resins |
| Hardened tool steel (H13, 1.2344) | 500,000 to 1,000,000 plus shots | 5 to 8 weeks | High volume, and abrasive glass or mineral filled resins |
| Stainless tool steel (S136, 420) | 500,000 plus shots | 6 to 9 weeks | Medical, optical clarity, PVC and other corrosive resins |
Tooling cost
Two tools for parts of similar size can differ by several times in price. These are the factors that explain the gap, in roughly the order they matter.
Larger parts need a bigger mold base, more steel to machine and a larger press, which raises both tool price and the hourly rate the part runs at.
More cavities cut the price per part but multiply the tool cost and the risk. Cavity count should follow the annual volume, not the other way round.
Moving from aluminum to pre hardened steel to hardened H13 adds material and machining hours, and buys tool life in return.
Every slide, lifter or unscrewing core is a moving assembly that has to be designed, fitted and maintained. Removing an undercut in DFM is usually the cheapest saving available.
Polishing to an optical finish, or applying a texture, is hand work on every cavity surface and scales with cavity count.
Tight tolerances drive slower machining, more bench fitting and more measurement at T1, and can force a steel choice that holds dimension over a long run.
Tooling decision
The honest test is not volume alone. It is whether the design is frozen. Cutting hardened steel around a design that is still moving is how programs lose both the tool budget and the schedule.
Lead time
Tooling lead time is mostly machining and fitting, but the two stages that slip most often are the ones that need your sign off.
Draft, wall thickness, gate and ejector locations and undercuts are agreed before any steel is cut. Changes are free at this stage and expensive after it.
Mold layout, cavity count, cooling and runner design go out for approval. Waiting on this sign off is the most common source of schedule loss.
Roughing, CNC and EDM work on cavities and cores, then polishing or texturing of the cosmetic surfaces.
The first parts off the tool. Expect to review dimensions, cosmetics and any sink or warp before the tool is signed off.
Measured results against the drawing, plus any tool rework agreed from the T1 review. Most tools take one or two rounds.
Tool is released to production with the process window recorded, so later runs reproduce the approved parts.
Questions customers ask
A simple single cavity aluminum prototype tool for a small part usually lands in the low thousands of dollars. A hardened multi cavity production tool with side actions for a larger part can reach the tens of thousands. Part size, cavity count, undercuts and steel choice explain nearly all of the range, so an accurate number needs the CAD file rather than a description.
On NetProto programs the customer owns the tool. That means it can be moved, and it means the tool drawing and steel specification are yours. Confirm ownership in writing with any supplier before the tool is cut, because it is difficult to renegotiate once the steel exists.
Aluminum prototype tools are typically two to three weeks to first parts. Pre hardened steel runs three to five weeks. Hardened production tools are usually five to eight weeks, and longer for stainless or for tools with several side actions. Add time for your own DFM and tool design approvals.
If the design is still likely to change, aluminum or pre hardened steel is the lower risk choice because a revision does not write off a production tool. If the design is frozen and annual volume is high, going straight to hardened steel avoids paying for two tools.
T1 means the first shots taken off a new tool. They are used to check dimensions, cosmetics and defects such as sink or warp before the tool is approved. Most tools need one or two rounds of rework after T1, and that time should be in your schedule.
Usually yes. Adding steel to close a feature is straightforward, while removing steel to add material is harder and sometimes needs a new insert. Transferring a tool from another supplier is common, and needs the tool drawing plus a condition check before it runs.
Ready to quote
Upload the CAD file and the quote comes back with the tooling route, the tool cost and the piece price together, so the tradeoff between them is visible before you commit.
