Author: Keith Day

The bracket supplier had done their job. They built what was on the print. But no one had stepped back to ask: does this slot orientation still match the real-world assembly?

It was a tooling-driven layout — makes sense for punch sequencing. But it didn’t align with the control unit’s mechanical stack-up. As a result, the entire system was fighting its own geometry under torque.

And here’s the kicker: the drawing didn’t clearly define the slot datum, only the tolerances. No GD&T callouts, no fit interface. The legacy CAD model had skipped over the nuance.

This kind of miss doesn’t get flagged in APQP. It gets flagged when a technician can’t close the lid.

The grounding tab had a modeled chamfer in CAD, but it wasn’t translated into a ballooned dimension or spec’d on the 2D print. The edge looked clean from a tooling standpoint — no visible burrs, no hanging material — but the profile came off the die sharp, with no radius and no control on contact resistance variation.

The tool itself used a high-speed progressive setup, and the forming station ran the tab through a basic bend and trim. No coining. No secondary deburr. No in-line edge break. From the supplier’s side, it met print. But from a compliance standpoint — particularly for electrical grounding in a flight system — it didn’t meet functional expectations.

These are the kinds of issues that don’t always show up in lab testing or pilot builds. They show up when regulators look for traceability, documentation, and process control — and ask, “How are you verifying this edge condition?”

The drawing told part of the story — bend angles, edge radii, a few critical dimensions. But it didn’t define the functional profile of the formed spring arm after stamping. And it didn’t specify any controls for springback, edge flatness, or post-form envelope.

Worse, the forming process was built as an air bend — totally fine for general tabs or brackets, but a poor choice for a critical flex component inside a tight moving assembly. That small forming choice, plus the missing functional spec, created a situation where the supplier could meet print — and still make parts that caused assembly failures.

This isn’t unique to surgical tools. I’ve seen the same in EV pressure sensors, drone latch systems, even avionics switch frames. When form-critical parts aren’t fully defined in the drawing — or verified with the right fixture — the risk creeps in silently.

Procurement professionals know that dimensional tolerances alone don’t guarantee performance. When inserts are overmolded, they need to do more than fit the print — they must feed, align, and hold position reliably under heat and pressure.

In 2025, automation is more common, cavity counts are higher, and mold uptime targets are tighter. That makes insert stability and flatness critical to uptime.

Without proper planarity, inserts can:

1. Jam robotic pickers

2. Misregister inside the cavity

3. Get crushed in clamp

4. Trigger mold safety stops

These issues don’t always show up on a CMM report — but they show up on the shop floor.

Flash around inserts isn’t always a tool wear issue. In many cases, it’s caused by inserts that didn’t fully seat in the cavity. That tiny gap? It may have come from a burr, a shear edge, or a part that didn’t lie flat where it needed to.

That’s not just cosmetic. For industries with compliance pressure — like medical, aerospace, defense, or sealed electronics — even slight flash can jeopardize first-pass yield or field reliability.

So, what’s the move for procurement? Step in before the RFQ stage to ensure inserts are sourced with mold-readiness in mind.

EDM is ideal for getting a quick, clean part into early testing. But progressive stamping introduces mechanical forces, springback, material flow, and edge conditions that EDM simply doesn’t account for.

Here’s where sourcing teams often run into trouble:

1. Tight internal radii or sharp edges that aren’t formable at speed

2. Flatness or profile specs that ignore springback or progressive forming distortion

3. Burr-free finishes in EDM that aren’t achievable without secondary ops in stamping

4. Drawings approved before DfM review, making revisions harder later

Without alignment early, you may face tool redesigns, production delays, or RFQs that bounce back for clarification — all of which cost time and credibility.

On paper, the stamped insert may meet spec. But if that spec doesn’t include edge break, burr height, or form profile, you’re introducing risk to every cavity the insert touches.

Common pain points sourcing teams face:

1. Mold cavities wearing out faster than expected

2. Flash showing up in validation or early production

3. Surprise tooling change orders from minor insert variations

4. Extended mold debug loops that delay NPI milestones

And when that happens?
You’re juggling tooling vendors, escalating with suppliers, and defending timelines that weren’t supposed to slip.

Stamped terminals do more than just connect wires. They need to maintain tight electrical contact and mechanical strength — under load, over time, and through environmental stress.

But here’s where it usually breaks down:
The print covers dimensions and material but doesn’t call out burr control, edge finish, or flatness near the crimp zone. The part passes dimensional checks — but with inconsistent surface quality or slight deformation. Crimp performance drops. Torque varies. And the field issue gets traced to “part variation” with no clear supplier fault.

This is where sourcing gets stuck holding the bag — even though the root issue started before tooling was cut.

Today’s precision-stamped components serve critical roles in regulated industries like medical devices, aerospace sensors, and automotive electronics. Even tiny imperfections, such as microscopic burrs or slight edge-roll from stamping, can lead to compliance risks (think FDA rejections, aerospace supplier audits, or automotive recall threats).

Here’s the reality: plating defects and molding misfits aren’t solved by extra inspection steps or secondary operations. Instead, they’re prevented by smarter tooling decisions made well before metal hits steel.

Good die design considers more than basic dimensional tolerances—it optimizes punch-to-die clearances, accounts for ideal shear angles, and uses simulations to manage material flow carefully. This proactive design ensures minimal burr formation, reduces edge-roll, and produces clean edges consistently.

Today’s precision-stamped components serve critical roles in regulated industries like medical devices, aerospace sensors, and automotive electronics. Even tiny imperfections, such as microscopic burrs or slight edge-roll from stamping, can lead to compliance risks (think FDA rejections, aerospace supplier audits, or automotive recall threats).

Here’s the reality: plating defects and molding misfits aren’t solved by extra inspection steps or secondary operations. Instead, they’re prevented by smarter tooling decisions made well before metal hits steel.

Good die design considers more than basic dimensional tolerances—it optimizes punch-to-die clearances, accounts for ideal shear angles, and uses simulations to manage material flow carefully. This proactive design ensures minimal burr formation, reduces edge-roll, and produces clean edges consistently.

You’re not just sending out RFQs. You’re managing timelines, risk exposure, supplier performance, and cost expectations.

When early-stage parts are built without a clear path to scalable production, you’re left managing the chaos:

1. Tooling quotes that shock stakeholders

2. Reopened sourcing because of part redesign

3. Conflicting secondary op specs (e.g., plating or tapping vendors not aligned)

4. Molders or assembly partners blaming part issues on “upstream sourcing”

5. Late-stage supplier hesitancy that stalls PPAPs

And here’s the kicker: none of it started with you—but it ends with you.

You’re not just buying parts—you’re managing production risk. And when inserts don’t seat right, the ripple effects hit:

1. Tooling life shrinks
2. Cycle time suffers
3. Scrap increases
4. The molder blames the stamper (and vice versa)

What you really need is predictability. Parts that fit the mold every time. Inserts that don’t require extra deburring or benchwork. Suppliers who understand that “close enough” isn’t good enough when it goes into a high-precision mold.