Mold Quote Comparison
Comparing Injection Molding Quotes | Why Prices Differ 3x
Why do injection mold quotes differ 3x for the same part? Steel, cavitation, tolerances, volume assumptions, payment terms — and a line-by-line method to compare quotes fairly.
A procurement manager sends the same STEP file to four molders and receives mold quotes of $4,200, $9,800, $15,000, and $28,000. The parts are identical. The geometry is identical. The difference is entirely in what each supplier assumed — and none of them listed their assumptions on the quote.
The $4,200 quote is an aluminum prototype mold that will last 20,000 shots. The $28,000 quote is an H13 four-cavity tool with a hot runner that will run two million. Comparing them as if they were the same product is how buyers end up paying for the wrong tool for five years.
This page explains where quote differences come from, and how to line quotes up side by side so you are comparing the same tool — plus the signals that tell you a low quote is a trap rather than a bargain.
Six Drivers of Quote Differences
| Driver | Why It Moves the Price | Typical Spread |
|---|---|---|
| Steel grade | Aluminum vs P20 vs H13 vs S136 — different tool life, different machining cost | 0.3–2.5× on the mold |
| Cavity count | Single vs multi-cavity changes mold cost up and part cost down | Mold 2.5–5×, part cost ÷4 |
| Hot runner | Eliminates runner waste, adds manifold and controller | +$3,000–$15,000 on the mold |
| Tolerances & finish | ±0.02mm and SPI A-2 polish need hard milling and manual polishing hours | 15–40% on the mold |
| Volume assumptions | A supplier quoting for 5,000 parts/year designs a different tool than one quoting for 500,000 | Changes everything downstream |
| Payment & IP terms | Deposit structure, tool ownership, and mold lifecycle obligations are priced differently | 5–15% on the program |
The full engineering detail behind these numbers is in the injection molding cost guide — here the focus is the comparison method.
The Line-by-Line Comparison Method
The fix for divergent quotes is specification. Send every supplier the same requirements, then check each quote against the same table:
| Line Item | What to Require | What It Tells You |
|---|---|---|
| Mold steel | Named grade (e.g. P20, H13, S136) and hardness spec | Tool life and maintenance cost |
| Cavity count | Stated on the quote | Real part cost, not just mold cost |
| Expected shot life | Number of shots the tool is guaranteed for | Whether the steel matches the volume |
| Cycle time | Stated, with part weight and gate type | Processing cost per part |
| Material price | Resin grade, price per kg, scrap rate | Whether the part cost is honest |
| Tolerances & finish | Which dimensions are held tight, SPI/VDI spec | Whether the tooling cost matches the drawing |
| DFM inclusions | Written DFM report with risk list | Depth of the supplier’s engineering |
| Sample & trial terms | T1 samples, trial data, FAI report included | What happens after the mold is built |
| Payment terms | Deposit, milestone, and balance structure | Cash-flow risk and leverage |
| Tool ownership | Who owns the tool, transfer policy, maintenance obligation | What happens in year three |
A quote that cannot answer these ten lines is not comparable. If the supplier will not state the steel grade or the cycle time in writing, treat the omission as a risk priced at zero.
Low-Quote Warning Signals
A low mold quote is sometimes a genuine bargain — an under-loaded toolroom pricing to fill capacity. More often it is one of these:
- Unstated steel. “Quality steel” is not a grade. A P20 tool quoted at an H13 price, or worse, an unspecified tool quoted at any price, is a liability.
- No shot-life guarantee. If the supplier will not say how many shots the tool is built for, the tool life is whatever it turns out to be.
- No DFM review. A supplier that cuts steel without a documented DFM review is cutting costs somewhere — usually in cooling design, ejection, or tolerances that you will pay for in part quality.
- No trial data. A mold without documented T1 trial data has no baseline. Production problems become invisible until your assembly line finds them.
- Unrealistic cycle time. A quoted part cost built on a 12-second cycle for a part that physically requires 25 seconds means the part cost will double at production. Ask for the cycle time and the shot weight.
The pattern across all five: a cheap quote that hides its assumptions transfers the cost to production, where it compounds. A $3,000 saving on the mold is lost within 30,000 parts if the part cost is $0.10 higher — the math is in the cost breakdown article.
How We Quote
Every JBRplas quote answers the ten comparison lines explicitly, because our buyers are comparing us against other factories — and we want the comparison to be real:
- Named steel and hardness, selected against your stated volume and shot-life requirement
- Stated cavity count and cycle time, with part weight and gate type
- Written DFM report before tooling — material recommendation, gate location, draft analysis, undercut identification, risk list
- T1 samples with full dimensional data, not a signed cover page — see our quality system
- Tool ownership and transfer terms in writing — see tool transfer
- Documented trial data: cycle time, injection pressure, temperatures, shot log — your production baseline
If you already hold quotes you cannot line up, send them with your part file. Our engineers will tell you what each quote is actually for — no charge, and we will quote the same part against the same specification. If you have not requested quotes yet, our RFQ preparation guide has the six-item checklist that produces comparable quotes from every supplier.
Frequently Asked Questions
Is the cheapest mold quote ever the right choice?
Sometimes — when the volume is low and the tool is honestly specified. An aluminum prototype mold at $4,200 for 5,000 parts is correct engineering. The same quote for a 500,000-part program is a trap. The volume determines which quote is “right”; the specification determines which quotes are comparable.
How much should quotes from different suppliers vary?
After specification, quotes for the same tool typically vary 10–20% — differences in overhead, labour rates, and margin. More than that means someone is quoting a different tool, pricing risk they see in your drawing, or making an error. Ask them to explain the difference in writing.
What should I do when suppliers refuse to state assumptions?
Eliminate them. A supplier that will not commit steel grade, cycle time, or shot life in writing will not commit to delivery dates either. There are thousands of molders; comparability is a basic professional standard, not a negotiation concession.
Do you charge for reviewing quotes from other suppliers?
No. Send the quotes and your part file, and our engineers will map each quote against the ten-line table and tell you what each one is actually for — even if you do not proceed with us.
Send your CAD file and project details for a quote that states every assumption in writing. DFM feedback, pricing, and lead time within 24 hours.