Last updated: 2026-09-04 · 5 min read

T1 Mold Trial Documentation Package — What Reports, Samples and Data Must the Mold Maker Deliver After the First Trial, and How Do You Review Them?

The T1 (first trial) documentation package includes 7 mandatory items: CMM report (full dimensional data for 5–10 samples), process parameter sheet, 10–20 labeled sample parts, trial video (50+ continuous shots), mold/part photographs, issue list with corrective actions, and steel/heat treatment records. Delivered within 5 working days. If any item is missing, the trial is incomplete — do not approve the mold or authorize T2.

Key Facts

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  • Seven mandatory items: CMM report (PDF + native data), process sheet (one per cavity if multi-cavity), 10–20 labeled samples, 50+ shot video, high-res photos, issue list with root cause + fix + target date, steel mill test reports + heat treatment certificates.
  • Four-step review: (1) CMM — check every critical dimension has actual values, deviation within tolerance; (2) process — cycle time within ±10% of quote, packing pressure 50–80% of injection; (3) sample — inspect for sink, flash, weld lines, fit; (4) video — check for sticking, flashing, inconsistent ejection.
  • Delivery: within 5 working days. T1→T2 typical for well-designed molds: 1–2 trials. More than 4 trials signals a fundamental design or DFM problem. Modification cost: mold maker pays for machining errors; customer pays for post-cutting design changes.

    • Runner system — The channel network that delivers melt from the machine nozzle to each cavity. Cold runner: solidifies between shots, produces runner waste. Hot runner: stays molten, eliminates runner waste but adds $15k–$40k to mold cost. The related guide covers adjacent topics.

    What Are the Seven Mandatory Items in a T1 Documentation Package?

    Seven items with contents, what each proves and delivery format:

    Item Contents What It Proves Format
    CMM report Full dimensional data for 5–10 samples, deviation from nominal for every dimension Mold holds tolerance — or identifies which dimensions are out of spec PDF + native data file (Excel/CSV)
    Process parameter sheet All machine settings: melt temp, mold temp, injection speed, packing pressure, cooling time, cycle time Process is stable and repeatable PDF, one per cavity if multi-cavity
    Sample parts (10–20) Labeled with mold ID, cavity number, shot number and date Customer can inspect independently — verify cosmetic, fit and function Shipped via express courier
    Trial video (50+ shots) Continuous run showing fill, pack, cool, open, eject and part drop Mold runs without sticking, flashing or cycle interruptions MP4 file on USB or cloud link
    Photographs Mold open/closed, cavity surfaces, parting line, ejector marks, cosmetic surfaces Visual record of mold condition at T1 — baseline for future maintenance High-resolution JPEG
    Issue list Problems discovered (sink, short shot, flash, sticking) with proposed fixes Transparency — mold maker acknowledges issues and has a fix plan PDF table: issue, root cause, fix, target date
    Steel and heat treat records Mill test reports for cavity steel, heat treatment certificates with hardness values Correct steel grade was used; hardness is within specification PDF, organized by insert

    If any of these seven items is missing, the trial is incomplete. A mold maker that delivers an incomplete T1 package is signaling either poor documentation discipline or an attempt to hide problems discovered during the trial.

    How Do You Review the T1 Package — and What Are the Acceptance Criteria?

    1. CMM report review. Check that every critical dimension on the drawing is reported with actual values (not just “OK”). Calculate the deviation from nominal for each dimension. If any critical dimension is outside tolerance, the mold must be modified before T2.
      If the deviation is within tolerance but close to the limit (above 75% of the tolerance band), note it as a risk for T2 monitoring.
    2. Process parameter review. Check that the cycle time matches the quotation (within ±10%). Check that the packing pressure is within the expected range (50–80% of injection pressure). Check that the mold temperature is within the resin supplier’s recommended range.
      If any parameter is outside the expected range, ask the mold maker to explain why.
    3. Sample inspection. Inspect the samples for cosmetic defects (sink, flash, weld lines, burn marks), dimensional fit (mate with mating parts if available) and function (snap fits, screw bosses, insert retention).
      If any defect is found, photograph it and add it to the issue list for the mold maker to address at T2.
    4. Video and photo review. Watch the trial video for signs of instability: sticking parts, flashing at the parting line, inconsistent ejection, or cycle interruptions. Check the photos for mold condition: clean parting lines, no rust on cavity surfaces, proper labeling of inserts and ejectors.
      Any issue in the video or photos should be added to the issue list.

    After the review, issue a written response: approve for production, approve with modifications (list each modification), or reject (list each failure). Do not authorize T2 until the review is complete and the response is issued.

    Cavity — The hollow space inside the mold that forms the part shape. Multi-cavity molds produce multiple parts per shot. Cavity count determines production output but also mold cost and complexity. Each cavity must be balanced for uniform fill. The related guide covers adjacent topics.

    A complete T1 package allows the customer to approve the mold remotely. An incomplete package forces additional trials, delays and cost overruns. The seven-item checklist is the minimum standard — any mold maker who cannot deliver all seven items within 5 working days should not be in production mold making.

  • Key parameter identified — critical variable confirmed against spec.
  • Tolerance within achievable range — commercial ±0.15mm or tighter as needed.
  • Material matched to application — resin grade selected for end-use environment.
  • Process window validated at T1 — parameters locked after first trial.
  • Inspection method defined — CMM, visual, or functional test specified.

    • Frequently Asked Questions

    How long after the T1 trial should the documentation package be delivered?

    Within 5 working days. The CMM report takes 1–2 days (measuring 5–10 samples on 20+ dimensions each); the process sheet and photographs are completed on the trial day; the video is edited and uploaded within 1 day; samples ship via express courier (2–3 days international). If the mold maker cannot deliver within 5 working days, it indicates poor organization or problems discovered during the trial that are being concealed.

    Set the 5-day delivery requirement in the purchase order before the deposit is paid.

    What if the CMM report shows dimensions outside tolerance — who pays for the modification?

    If the dimension is outside tolerance because of a mold design or machining error, the mold maker pays — this is covered by the mold warranty. If the dimension is outside because of a design change requested by the customer after the mold was cut, the customer pays. The contract should specify which party bears the cost of T1 modifications.

    The default in the mold making industry: the mold maker is responsible for all modifications required to bring the mold into tolerance, unless the customer changed the design after the mold was approved for cutting.

    How many T1 trials are typical before the mold is approved?

    For a well-designed mold with mold flow analysis and a thorough DFM review, 1–2 trials are typical. T1 identifies the issues; the mold is modified; T2 confirms the fix. For complex molds with multiple side actions, hot runners or tight tolerances, 3–4 trials may be needed. If the mold requires more than 4 trials, there is a fundamental problem with the mold design, the mold flow analysis or the DFM review — and the root cause should be investigated before continuing.

    Each additional trial costs $300–800 (machine time, material, labor) and adds 1–2 weeks to the timeline.

    Key Takeaways

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  • T1 package: 7 mandatory items — CMM report, process sheet, 10–20 samples, video, photos, issue list, steel records.
  • Delivery: within 5 working days. If any item is missing, the trial is incomplete.
  • Four-step review: CMM → process → sample → video.
    Issue written response before authorizing T2.
  • 1–2 trials typical; more than 4 signals a fundamental design or DFM problem.

    • If you have received a T1 package and need help reviewing the CMM data, process parameters or sample condition, send the package for an independent T1 review. The review identifies which dimensions are within tolerance, which require mold modification, and whether the process parameters indicate a stable production process.

    Sources: Society of Plastics Engineers (SPE) — First Article Inspection Guidelines · ASTM International — Mold Trial Standards · Osswald, Injection Molding Handbook · LKM Mold Base — T1 Documentation Requirements · HASCO Standard Parts — Mold Trial Checklist

    — Arthur, Tooling Engineer at aCatMould