Rapid Tooling for Injection Molding
A rapid tool is not a production tool made badly. It is a different design made for a different job, and knowing the difference is what stops a programme from buying the wrong one. We build CNC machined aluminium tools and hardened steel bridge tools, and we will tell you plainly which one your volume actually needs.
Free Consultation2 to 3 weeks
Aluminium Tool Lead Time
25 pieces
Starts At
500 to 5,000 shots
Aluminium Tool Life
Free, 24h
DFM Review
Materials
| Grade | Properties | Typical Applications |
|---|---|---|
| Aluminium 6061-T651 | Thermal conductivity around 165 watt per metre kelvin, roughly five times tool steel, machineable at high speed which shortens lead time, takes hardcoat anodising to raise surface hardness after machining | Prototype and low volume cavity blocks, core inserts, pilot tools up to about 5,000 shots |
| Aluminium 7075-T6 | Higher strength and hardness than 6061 with slightly lower thermal conductivity, better resistance to parting line wear and shutoff damage on longer low volume runs | Runs approaching the upper end of aluminium tool life, parts with deep shutoffs, tools with more ejector cycles |
| Pre-Hardened Steel 1.2312 (P20 plus sulphur) | Supplied hardened to around 30 HRC, machineable, noticeably more wear resistant than aluminium at tighter shutoffs and land areas | Bridge tooling where the part has abrasive content or deeper shutoffs, and where the tool has to hold tolerance past a few thousand shots |
| P20 Pre-Hardened Mould Steel | Around 28 to 34 HRC through section, even hardness without heat treatment, good polishability, the standard production tool base | Production tools and the usual answer once volume justifies replacing rapid tooling |
| Hardened Insert Steel (H13 or 1.2344) | 48 to 52 HRC after heat treatment, used selectively as an insert inside an aluminium tool at wear points rather than as the whole tool | Shutoff faces, thin land areas, slider faces and any place where wear would first appear in an aluminium tool |
| Ejector and Wear Components | Hardened ejector pins, bushes and wear plates fitted into aluminium tools so the soft parent material does not gall against itself over repeated cycles | Every aluminium tool, since the failure mode of aluminium is wear and galling at moving interfaces rather than cracking |
Process Parameters
| Parameter | Standard Range |
|---|---|
| Aluminium Tooling Lead Time | 2 to 3 weeks |
| Bridge Steel Tooling Lead Time | 3 to 4 weeks |
| Production Steel Tooling Lead Time | 4 to 6 weeks |
| Aluminium Tool Life Expectation | 500 to 5,000 shots depending on resin, fill content and part complexity |
| Bridge Steel Tool Life Expectation | 10,000 to 50,000 shots |
| Recommended Draft on Aluminium | 1.5 to 3 degrees per side, more than a steel tool needs |
| Cavitation on Rapid Tooling | Single cavity standard, 2 to 4 cavities where volume justifies it |
| Maximum Moulded Part Size | up to 800 x 600 x 400 mm |
| Machine Range Available | 50 to 800 T |
| Part Tolerance | plus or minus 0.05 mm standard, tighter by agreement on critical features |
Surface Finishes
As Machined
The surface left by the cutter, with tool witness marks visible. This is often all a functional pilot part needs, and it keeps a rapid tool at its fastest lead time. Where the part is going to be reviewed for appearance, cutting strategy is planned so witness marks fall away from visible faces rather than being sanded afterwards.
VDI 3400 Texture
Available on aluminium, though the etch behaves slightly differently on aluminium than on steel and is generally coarser. Texture is also a practical way to cover witness marks on a prototype part, which makes it more useful in rapid tooling than in production tooling.
Bead Blasting
A uniform satin finish produced with glass or ceramic media, giving a consistent appearance without the cost or lead time of a chemical etch. Frequently the best balance for a low volume tool where appearance matters but the quantity does not justify a full texture.
Hardcoat Anodising
An electrochemical treatment that builds a hard oxide layer on the aluminium surface, reaching surface hardness around HV 400 to 600. Used on the wearing faces of a rapid tool this noticeably extends usable life, though it changes dimensions slightly and has to be allowed for in the cavity.
Hardened Inserts at Wear Points
Rather than hardening the whole tool, H13 inserts are placed at the shutoffs, lands and slider contact faces. It costs a little more than plain aluminium and it deals with the specific places a rapid tool wears first, which is usually more effective than trying to make the whole cavity hard.
Polish Limits on Aluminium
Aluminium does not take or hold a high polish and it will not produce an optical grade. The honest statement is that clear and optical parts need steel tooling. We will say this at review rather than after you have waited for parts that cannot meet the requirement.
Design for Manufacturing (DFM)
- Add more draft than a steel tool needs, because aluminium has higher surface friction and every additional degree of draft reduces ejection force and tool wear
- Generous radii at shutoffs and lands, since sharp edges are the first thing to break down in a soft tool
- Avoid glass filled resins in aluminium tooling, because the fibre abrades the cavity and turns a 5,000 shot tool into a 1,000 shot one
- Keep wall variation low, since aluminium conducts heat away quickly and unevenly, and that combination moves dimensions more than steel would
- Use hardened inserts at shutoffs rather than hoping the parent material holds up, which it usually will not past a few thousand cycles
- Watch sustained mould temperature with high temperature resins, because aluminium loses strength well before steel does
- Plan the switch to production tooling before you need it, since a bridge tool reaching end of life is not the same as it failing suddenly
- Single cavity unless there is a reason not to be, because additional cavities add cost and rarely pay back in a low quantity
- Freeze the design before cutting steel, and accept that the aluminium stage exists partly so you can find what is wrong
- Upload STEP, IGES or DXF files and receive a free tooling route recommendation with DFM within 24 hours
Tooling & Capacity
| Type | Lead Time | Suitable For |
|---|---|---|
| CNC Machined Aluminium Tool | 2 to 3 weeks | 25 to 500 pieces, pilot runs, market testing, design freeze batches, proving geometry before production tooling |
| Aluminium Tool with Hardened Inserts | 2 to 3 weeks | 500 to 5,000 pieces or parts with deep shutoffs, where plain aluminium would wear at the interfaces first |
| Pre-Hardened Steel Bridge Tool | 3 to 4 weeks | 5,000 to 50,000 pieces, glass filled resins, parts with demanding shutoffs or tolerance requirements |
| Production Hardened Steel Tool | 4 to 6 weeks | Above roughly 20,000 pieces a year per part number, long programmes, and any part that will be moulded repeatedly for years |
Quality Assurance
- Tool drawings issued before machining starts, so the layout, gating and ejection are reviewed rather than discovered
- Dimensional check of the cavity before the first trial shot, independent of whether the tool is aluminium or steel
- Trial shots run at production capable settings, with the parameters recorded and retained for repeat runs
- First article inspection report issued with the T1 samples, not after you have asked for it
- Cooling balance checked on the tool before running, which matters more on aluminium than most people expect
- Ejector travel and witness marks reviewed on the first shots while the tool can still be adjusted cheaply
- Shot count recorded for every run on the tool, and the running total available to you at any time
- Tool inspected and maintained between campaigns, with any wear found reported to you rather than absorbed silently
- Every lot ships with a dimensional report and material certificate, and the Certificate of Origin is included
- SGS, Bureau Veritas or TUV inspection is arranged at any stage on request for rapid tool and trial parts
Applications
- Prototype parts for design validation and bench testing
- Market test batches before committing to production tooling
- Crowdfunding and pre-launch sample quantities
- Bridge production while slower tooling is being built elsewhere
- Spare and aftermarket parts with modest demand
- Dimensional and fit trials against mating assemblies
- Colour and material trials on real tooled parts
- Regional variants that do not justify a full production tool
- Pre-series builds supporting a design freeze decision
Why Choose FHY Precision
Two to three weeks to first parts, which changes what you can learn before committing to a production tool
Tooling route recommended against your actual quantity rather than sold as the most expensive option available
Honest statement of tool life and wear limits before quoting, including where aluminium is the wrong choice
Hardened inserts and hardcoat anodising used where they extend life rather than as an upsell
Trial parameters, drawings and shot count retained, so the switch to production tooling carries the learning forward
Tool held in store and maintained between campaigns rather than scrapped after one run
Resin lot traceability and the documentation are issued at any order size, with third-party inspection on request
Rapid tools built and run in our China plant with one purchase order covering tool, trials and parts
FAQ
1. How many parts can an aluminium tool actually produce?
Realistically 500 to 5,000 shots, and the range is that wide because wear dominates. Unfilled ABS or PP with generous radii and hardened ejectors sits at the upper end. Glass filled resin, thin lands or deep shutoffs sits at the lower end. We give you a number for your specific part at quote rather than quoting the best case.
2. When should I choose steel bridge tooling instead of aluminium?
When either the quantity or the material pushes past what aluminium will survive. Practically that means above 5,000 pieces, or any glass filled or mineral filled resin regardless of quantity. The abrasive content attacks aluminium quickly, and paying for pre-hardened steel from the start is cheaper than replacing a worn tool halfway through.
3. Is a rapid tool as accurate as a production tool?
For most parts, yes. The dimensional capability of the tool is set by machining accuracy, and modern CNC holds that equally well in aluminium. What differs is how long the tool holds it. A production tool holds tolerance for hundreds of thousands of shots; an aluminium tool holds it for thousands, and for the quantity it serves that is sufficient.
4. Why does aluminium need more draft angle?
Two reasons. Aluminium has a higher coefficient of friction against most resins than polished steel does, so the part grips during ejection, and aluminium surfaces damage more easily if the ejection force is high. Additional draft reduces that force, protects the cavity and makes ejection repeatable. We typically ask for 1.5 to 3 degrees per side.
5. Can you make a transparent or optical part in rapid tooling?
Not to an optical or high gloss standard. Aluminium will not take or hold the polish those surfaces require, and we prefer to say this at review rather than after you have waited two weeks. Clear work is quoted on a polished steel tool, where a single cavity polished prototype version runs around 3 to 4 weeks and a production tool longer.
6. What is the difference between a prototype tool and a bridge tool?
Intended life and material. A prototype tool is usually aluminium and aimed at producing hundreds of parts to prove a design. A bridge tool is pre-hardened steel aimed at producing tens of thousands while demand is still being established. The names describe what they bridge towards, not how carefully they were made.
7. Can you run high temperature resins like PC or PA in aluminium tooling?
Yes within limits. Aluminium alloys begin to lose strength at sustained temperature well below anything that would trouble steel, so for PC requiring a hot mould we check the continuous operating temperature and often add hardened inserts. It works, but it should be designed for rather than assumed.
8. Do you own the tool or do I?
You do. Tooling is quoted and paid once, we store and maintain it, and we will release it with its shot record and maintenance history if you ever move the programme elsewhere. We would rather you know that up front than discover there was a condition attached.
9. Can rapid tooling be multi cavity?
Yes technically, up to four cavities, though single cavity is the usual answer. Additional cavities add cost and complexity for a saving that only appears at quantity. If the low number is a bridge towards higher volume, we will quote single cavity now with a production tool quoted alongside for comparison.
10. What happens when the aluminium tool wears out?
It does not wear out suddenly, which is the useful part. Dimensional drift or flash at a shutoff appears gradually, and because we record shot counts we can see it coming. At that point you either switch to production tooling, which we will have quoted already, or rebuild the inserts for another campaign.
11. How quickly can I get the first parts?
Two to three weeks for aluminium tooling from frozen design, and the DFM comes back within 24 hours. In practice the schedule usually slips on design changes rather than on machining. That is expected, since the aluminium stage exists partly so you can find the problems you would rather not find in hardened steel.
12. Do you reuse the learning from the rapid tool in production tooling?
Yes, and this is the strongest argument for doing it this way. Gate position, cooling balance, shrink behaviour and warp tendency are all measured on the aluminium tool and carried into the production design. Correcting any of those after the steel tool is cut costs substantially more.
13. Is rapid tooling cheaper than I think?
Usually yes for aluminium, because it machines quickly. The honest caveat is that low tooling cost can disguise high piece cost if you run it beyond its intended volume. We quote tooling and pieces separately so you can see that relationship rather than discovering it in the third repeat order.
14. What files do you need for a tooling quote?
A 3D model in STEP or IGES, a 2D drawing with tolerances and cosmetic requirements, the resin, the expected quantity now and the estimated annual volume later, and whether those two numbers are genuinely different. That last answer decides the tooling route more than anything else.
15. Can you machine the tool from my existing design if the tool already exists elsewhere?
Yes. Send the tool drawings or the part model and we will quote machining a replacement or a backup. If you are moving an existing programme, send the process parameters as well if you have them, since starting from a known good process is faster than rediscovering one.
16. Do you offer third-party inspection?
Yes. SGS, Bureau Veritas or TUV can attend tool trials, witness first article measurement or inspect parts before shipment. For a first offshore tool this is often worth doing once, because it gives you an independent record of what the tool actually produced rather than a claim about what it should.