Why Two Mold Quotes for the Same Part Differ by 300% (2026 Breakdown)

The 300% is almost never margin. Only four things can open a gap that wide: cavity count, the runner system, a steel change that crosses from pre-hardened into stainless, or a production tool being compared against a bridge tool. When two quotes for the same part sit 3× apart and none of those four differ, they are not quoting the same object — and renegotiating price will not close it. Buyers asking why do two injection mold quotes differ so much expect a story about greedy suppliers. The arithmetic says otherwise.

1. Which Cost Drivers Can Actually Reach 300%?

Steel cannot, and steel is the one everybody negotiates — which is why the question why do two injection mold quotes differ so much keeps getting answered wrongly. Mold steel is 15–25% of a tool's invoice while CNC and EDM together are 35–50%. Double your steel grade and the invoice moves 8–12%. That is the ceiling. A supplier explaining a 3× quote with "we use better steel" is either describing a steel class change or has never opened his own cost sheet.

The steel line still deserves your attention, for a different reason. A standard 6050 mold base — 600 × 500 × 450 mm — weighs 1,060 kg at 7.85 g/cm³, split roughly 45% cavity plates, 20% spacer blocks, 15% ejector and bottom plates, 20% mounting plates. Only the cavity plates touch plastic. The other 55% resists clamping force, and 45 steel at ¥6/kg does that as well as 718H at ¥26/kg. So the same block bills four ways:

• All P20 at ¥13/kg — ¥13,780

• P20 cavities, 45-steel rear — ¥9,699

• 718H cavities, 45-steel rear — ¥15,900

• All 718H at ¥26/kg — ¥27,560

Four quotes, one word on the page — "P20" or "718H" — and a 2.8× spread on steel alone. It stays invisible because the line names a grade, never kilograms. It is also the cheapest legitimate saving in tooling: rear-half 45 steel is standard in South China, and its one real cost is corrosion, which a ¥0.8/kg black oxide pass handles. COLOSI quotes plate by plate for this reason — Sanmen Dexin Machinery Co., Ltd. has run its own toolroom since 2013, so the kilogram count on a quote is a purchase order, not an estimate.

Four drivers can open a gap of 300%. Every same part different mold price 300 percent difference traces back to one of them.

Two rows carry a warning. "Hot runner included" is not a specification: a 4-drop open gate from a Chinese brand adds $5,000–8,000, while a branded valve-gate manifold adds $12,000–45,000 to the same tool — and a quote omitting the brand has chosen for you. A tool with no stated shot-life warranty is a bridge tool — aluminium, 1,000–5,000 shots — at a production price, or a production tool sold as a bargain.

✅ Bottom line: Steel grade moves a quote 8–12% and margin 13%; only cavitation, runner spec or steel class produces 300%, so check those three before discussing price.

2. How Do You Compare Injection Mold Quotes Line by Line?

You stop comparing totals and force both quotes into the same eleven lines, then read the blanks — cheap quotes are rarely cheaper on any line, they simply have fewer lines. That is the mechanical version of how to compare injection mold quotes line by line, and it works on quotes written by shops that have never seen your format.

Demand six buckets in order: mold base (in-house or LKM, plate materials and kilograms) · cavity and core steel (grade, mill, weight) · machining (CNC and EDM hours, and at what rate) · finishing (SPI class, texture per side, polishing hours) · runner and components (manifold brand, gate type, drops, controller?) · trial and scope (T1/T2 rounds, FAI or PPAP level, moldflow, spares, crating, freight).

The blanks are the diagnosis, and how to compare injection mold quotes line by line comes down to reading them. Four recur: no hour count, no steel weight, no SPI class, no shot-life warranty. Each blank is a line the supplier can move after you sign, and moved lines are where a cheap tool turns expensive.

Here is that same part different mold price 300 percent difference rebuilt from 2026 China pricing — a PP lid, 3535 base, both quotes at 20% margin.

Cavitation and runner spec account for 62% of the gap. Margin — the thing buyers blame — is 17%. Finishing, the only line where B is genuinely better, is 9%. Those hour rates are the ones COLOSI works to, and they sit inside the published China band of $8–18/hr for a 160–250T press.

The table cannot answer the one question that matters: did you ask for a hot runner and SPI B1? If not, you compared a tool you specified against one you did not, and the 300% is your own RFQ talking.

✅ Bottom line: Normalise both quotes to eleven lines and the 300% resolves into two or three lines you can genuinely buy or refuse.

FAQ

Q: One quote is half the other and both say P20. Is the cheap one cutting corners? A: Not necessarily. P20 is three words covering anything from an imported block to 45 steel sitting behind P20 cavity plates. Ask for kilograms and a plate-by-plate list before assuming fraud. Once you see the number, why do two injection mold quotes differ so much stops being a mystery — one quote is for 477 kg of P20, the other for 1,060 kg.

Q: Can I send the same drawing to both and ask them to re-quote identically? A: It fails: most factories cannot itemise machining hours and simply restate the total. Send the eleven-line template with empty cells instead. A custom molder with its own toolroom fills it in a day; a broker cannot fill it at all, which is the answer you needed.

Q: Does a higher quote mean a mold that lasts longer? A: Only when the extra money lands in steel class, cooling design or polishing hours. Shot life is set by those three plus maintenance, not by price. A quote 40% higher for the same steel, cavitation and runner is 40% margin. COLOSI will not issue a tooling quote without a shot-life figure in writing.

Send Us Two Quotes and We Will Mark Up the Difference

If you are holding two quotes and cannot see where ¥57,000 went, send both to COLOSI. We return one comparison table — eleven lines, gaps attributed, blanks flagged — free, whether or not the tool lands with us. Sanmen Dexin Machinery Co., Ltd. has run its own mold shop and presses since 2013, so the hours and kilograms are numbers we fill in daily, not estimates. Ask for the line-item template and a wholesale tooling quote on your next OEM program.

Published: November 2026 | Sanmen Dexin Machinery Co., Ltd.

Email Address：：dexinxiaoqu@zjcolosi.com

Mobile Phone：+86 18967604333

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