Design for manufacturability in metal stamping is the layer of supplier value most procurement scorecards don’t measure. It’s the engineering improvements your supplier proposes that make the part work better in your downstream production. When those improvements are good, they get built into the customer’s process. Once they’re built in, they tend to stay.
We have examples that span fifty years. Design changes we proposed in the 1970s that stayed in a customer’s production until the relationship ended in 2022. A tooling approach built in 2003 that’s still running the F-150 program 23 years later. The common thread is that none of these improvements showed up in the RFQ. They showed up in the operational data after we’d been running the program for a while and understood what was really constraining our customer’s process.
The 1975 weld projection: design for manufacturability in metal stamping, applied
In 1975, we were quoting new 3-inch filter plates for an Oil Filter OEM. The industry-standard geometry for the weld projection on these plates was a flat round surface. The customer’s downstream weld operation was a major constraint in their filter assembly line. They welded the filter plate to the housing at high speed, and the geometry of the weld projection determined how fast and how consistently that weld could happen.
The flat round surface created problems. Welding electrodes made contact over a wide area, which dispersed current, extended weld times, and produced inconsistent weld quality. The customer was running up against the physical limits of their assembly line.
We proposed a different geometry. Instead of a flat surface, we designed a dome. The dome concentrated the welding current at a specific point, which melted the metal faster, produced a more consistent weld, and increased the rate at which the customer could run their line. Historical welding references at the time already showed that dome projections welded faster than flat ones. The industry hadn’t adopted the dome because the tooling to produce it was more demanding. We had the
in-house tool and die capability to make the dome tooling work.
The dome weld projection stayed in production from 1975 until the customer relationship ended in 2022. Forty-seven years. The specific tools we built evolved over time, but the dome geometry itself was designed into the part at the plate level, and once the customer validated it, it stayed. It’s a concrete example of what design for manufacturability in metal stamping produces when the supplier actually does the engineering work.
The extrusion chamfer
A second improvement from the same relationship: the extrusion feature on the filter plate.
The extrusion feature is the tapped hole that mounts the oil filter to your vehicle during oil changes. It’s a drawn-out tube pressed into the center of the filter plate. The customer’s internal process involved tapping threads into that extrusion so the finished filter would screw onto the vehicle’s filter mount.
The industry-standard extrusion had a flat surface at the end. When the tap started cutting threads into it, the flat surface tended to fracture. Fractures created stray burrs. Stray burrs in an oil filter are not acceptable. They can detach, enter the oil flow, and damage the engine. The customer was running quality holds and rework cycles on filters that fractured during tapping.
We redesigned the extrusion with an internal chamfer at the end. The chamfer gave the tap a clean entry point, which eliminated the fracturing problem at the source. No fractures, no stray burrs, no quality holds. The tap also lasted longer because it wasn’t fighting against a fractured surface on every cycle, which meant less downtime on the customer’s internal threading operation.
Like the dome weld projection, the internal chamfer stayed in the design permanently. Design for manufacturability in metal stamping doesn’t always mean changing the obvious geometry. Sometimes it means fixing a feature nobody flagged.
The F-150 example
Not every DFM improvement is a geometry change. Sometimes it’s a tooling approach.
In 2003, we built three dies for an NVH Tier 1 supplier for F-150 front strut mount production. The dies were engineered specifically for the presses we ran them on, with interchangeable sections that let us produce multiple part variants from the same base tool. The customer’s cost model when we quoted the program assumed we would need to rebuild or replace the dies as the F-150 program refreshed through multiple vehicle generations.
Twenty-three years later, the dies are still running. Same base tools, slightly modified parts, multiple F-150 program generations later. The customer paid for the die once in 2003 and hasn’t paid for tooling on that program since. That’s not something we promised in the RFQ. It’s something that showed up in the production data after we’d been running the program for a decade. We cover the economics of that model in more detail in our post on
long-life stamping tooling.
What this requires from a supplier
Design for manufacturability —
as a broader engineering discipline — is the practice of designing parts so they can be produced reliably and economically. At the supplier level, it requires three things most stamping shops don’t have simultaneously.
The first is in-house engineering capability. The specific knowledge of how your downstream process works doesn’t come from a supplier who takes drawings over the fence. It comes from engineers who have worked on your floor, seen the welding bottleneck or the tapping fractures firsthand, and have the authority to propose a design change on their own initiative.
The second is in-house tool and die capability. A design change that only works with new tooling is only possible if the supplier can build that tooling themselves. If the shop has to go out to a tool and die vendor to produce the dome weld projection or the internal chamfer, the economics don’t work. The supplier can’t justify the investment without passing it on, and the customer typically won’t fund speculative tooling.
The third is a customer relationship stable enough to see the improvement validated into production. DFM improvements take years to prove out. You run the first batch, you see the downstream data, you adjust, you run again. That cycle only happens if the supplier is still the supplier after the first few batches. Suppliers who get resourced every two years don’t get to make durable DFM contributions. We talked about why that stability matters in our
filtration supply chain stability post.
Why this matters more now than it used to
Three shifts are making DFM-capable suppliers more valuable than they were a decade ago.
The first is downstream automation. Customers are automating more of their assembly, welding, and inspection operations. Automated processes are more sensitive to part-to-part variation than manual ones were. A weld projection that works at 95% consistency in a manual operation might work at only 60% in a fully automated line. Suppliers who can propose geometry improvements that specifically target automation reliability are solving the exact problem their customers are investing to solve.
The second is lean manufacturing pressure on inventory and quality. Lean operations assume upstream components arrive consistent and tap-ready. DFM improvements that eliminate quality holds, rework cycles, or hidden scrap at the customer’s facility compound over time. A customer running lean cannot afford a supplier whose parts introduce variability into the line.
The third is the thinning of supplier bases with real engineering capability. Twenty years ago, most stamping suppliers had at least some in-house engineering. Today, a lot of the industry has outsourced tool and die, outsourced engineering, and reduced itself to running presses. Suppliers with the full stack (engineering, tool and die, production, maintenance) are rare. The ones that remain are increasingly valuable because the DFM contribution they can make is one most of their competitors cannot match.
Where we fit
We’re a fourth-generation, family-owned precision metal stamping manufacturer in Celina, Ohio. We have in-house engineering, in-house tool and die, in-house
progressive and transfer die capability, and the multi-generational customer relationships that let design improvements get validated and stay in production. The 1975 weld projection, the extrusion chamfer, the F-150 tooling approach, and dozens of smaller DFM contributions across other programs are the kind of engineering work we’ve been doing since 1948.
Design for manufacturability in metal stamping is not a line item on a quote. It’s the output of an engineering team that has the room, the tooling, and the customer relationship to actually improve the part.
If you’re evaluating stamping suppliers and the engineering side of the relationship matters to your program,
send us your specs. We’ll walk you through what we see in the part design and what we think we can improve.
