If you build hardware, sooner or later your enclosure, clip or cap needs an injection mould. For many software-first teams, the toolroom is a black box: you send a STEP file and weeks later parts appear.

It helps to think of mould making the way you think of a delivery pipeline. Each stage has inputs, checks and an artifact it hands to the next stage. Here is how we run it at Madhav Plasto Mould, a mould manufacturer in Bakrol GIDC, Ahmedabad, India.

(100-second walkthrough of the nine stages.)

The pipeline at a glance 

enquiry -> DFM -> design -> CAM -> machining/EDM -> assembly -> T1 trial -> corrections -> delivery 24h 2-3d 1-2w 3-5d longest stage (if needed) 5-10 weeks total

A complete production mould typically takes 5-10 weeks; a prototype mould from 2-4 weeks, depending on complexity.

Stage by stage

1. Enquiry and RFQ

  • Input: part drawing, 3D CAD, production needs
  • Check: engineers confirm requirements and the mould type that fits the part
  • Artifact: acknowledgement, open questions, quote scope (within 24 hours)

2. DFM review

  • Input: frozen part data
  • Check: draft, wall thickness, ribs and bosses, gate location, undercuts, shrinkage, tolerances
  • Artifact: DFM feedback with recommended changes and a practical quote (2-3 working days)

Think of DFM as code review for geometry. A missing draft angle is cheap to fix in CAD and expensive to fix in hardened steel.

3. Mould design

  • Input: DFM-approved part
  • Check: parting line, cavity layout, runner and gating, cooling circuits, ejection, slides or lifters, mould base
  • Artifact: 2D/3D mould design, approved by you before steel is cut (1-2 weeks)

This is the "merge approval" gate. After it, changes get costly.

4. CAM programming

  • Input: approved geometry
  • Artifact: CNC/VMC toolpaths and electrode programmes for EDM (3-5 working days, often parallel with late design)

5. Machining and EDM

  • Input: programmes and steel
  • Process: CNC and VMC machining, hardening where required, sinker and wire EDM, surface and cylindrical grinding, jig boring
  • Artifact: machined core, cavity, inserts and plates, checked against the design

This is the longest stage. Its duration scales with size, cavity count, steel grade and the number of actions.

6. Assembly and fitting

  • Process: polishing to the specified finish; fitting slides, lifters, ejection, cooling connections and hot runner parts where used
  • Artifact: assembled mould, ready for its first trial

7. T1 trial

  • Check: the mould runs on an injection moulding machine with the specified material; samples are checked for fill, appearance, dimensions and ejection using CMM, height gauges and other gauges
  • Artifact: T1 samples, trial observations and inspection results

T1 is your integration test. It is a verification step, not a failure if something needs tuning.

8. Corrections and re-trial

  • Runs only if T1 shows a need. Steel is corrected, often using steel-safe allowances planned at design stage, then re-trialled.

9. Delivery and support

  • Artifact: production-ready mould, documentation and after-sales support (spares, changes, troubleshooting).

Your "config file" for a quote

The more complete your inputs, the faster the pipeline starts:

part_drawing: 2D with critical dimensions cad: STEP or IGES material: resin grade (+ fillers, e.g. glass fibre) annual_volume: expected yearly qty and programme life cavities: number, or a cycle-time target machine: press tonnage and platen details (if fixed) finish: surface finish / texture for visible faces target_date: launch date

You do not need every field on day one; gaps are closed during DFM.

Lessons that transfer from software

  • Shift left. Problems found in DFM cost hours; problems found at T1 cost days.
  • Freeze scope. Late part changes extend lead time more than machining does.
  • Fast reviews unblock the pipeline. Prompt design approval is one of the easiest ways to protect the schedule.

FAQ

How is an injection mould made?
Through nine stages: enquiry, DFM review, mould design, CAM, machining and EDM, assembly, T1 trial, corrections and delivery.

How long does it take?
Typically 5-10 weeks for a complete mould, from 2-4 weeks for a prototype mould.

What file format should I send?
A 2D drawing with critical dimensions plus a 3D model, for example STEP or IGES.

Are moulds tested before delivery?
Yes, every mould is trialled and samples are checked against your drawing.

Full details and timelines: madhavplastomould.com/process.html

About: Madhav Plasto Mould is a precision plastic mould and die manufacturer at Bakrol GIDC, Ahmedabad, Gujarat, India, founded in February 2023 and led by CEO Nayan Dalsaniya.

Website: madhavplastomould.com · WhatsApp: +91-7383314026 · Email: madhavplastomould@gmail.com · Instagram: @madhav_plasto_mould · YouTube: @MadhavplastoMould

Photo credit: images from madhavplastomould.com; mould photographs by Bricetofly via Wikimedia Commons (CC0, public domain).