Stacking: Minimizing the Shipping Cost for Stamped Parts
- Qiaodong Cui
- 4 days ago
- 5 min read
Pack Studio Technical Series 3 of 4
Technical Series on Pack Studio written by Qiaodong Cui Lead Technical Inventor at Pack Studio.
Stamped parts — trays, pans, panels, brackets — are mostly air inside their bounding box. These parts are best packed by stacking them, and finding a good stacking orientation matters enormously. Pack Studio’s Stacking method works out the best orientation in which each part nests into the next and builds tight nested columns, so far more parts ride on every truck — and each one costs far less to ship.
Stamped parts are challenging to pack because they rarely fill their own bounding box; packed in compartments, the truck ships mostly air. But stamped parts have a redeeming feature: they nest. Two identical trays telescope into one another so the pair is barely taller than one, and a row of panels stands on edge like plates in a rack. The way to ship them with minimal cost is to stack them into a tight column — and that is exactly what the Stacking mode does. It also finds the best orientation in which to stack the part tightly, delivering higher packing densities than other modes — for example, Flexible Layering with a manually picked orientation.
Different ways to stack parts
Pack Studio Stacking allows you to build realistic concepts for your stamped parts with the following settings:
Stacking Direction. Vertical builds columns that run up the box — trays and pans telescoping upward, the way they stack on a shelf. Horizontal lays the column along the floor — panels and covers stood on edge, nesting face-to-face like records in a crate.
Max Adjustment Angle. How far Pack Studio may tilt the part off the chosen orientation while hunting for the tightest nest — 0–45°. A larger angle admits steeper nests (a tray that packs best tipped a few degrees); 0° forces an upright stack.
Space Between Parts / Stacks / Layers. Three independent clearances — between parts within a column (this one sets the pitch), between adjacent stacks, and between stacked layers — enough to keep the pack manufacturable without wasting room.
Max Parts Per Stack. Caps how tall a column may grow, for when a full-height stack would be too tall or too heavy to handle safely.
The study: two stamped parts
To put numbers on it, we took two representative stamped parts and packed each one twice — once with a common layer pack, and once with Stacking. We compare the two modes with the same settings, and conduct a real cost study.
The setup | Value |
Pallet / truck | 48 × 40 in pallet, 53 ft dry van |
Freight | $200 per delivery + $2/mi × 100 mi |
Part 1 · a stamped steel bracket
The first part is a stamped steel bracket. Laid flat in its Minimal 1 orientation it spans about 11.4 × 9.7 in yet stands under 2 in tall, and it weighs 1.4 lb. Packed conventionally with Flexible Layering, fourteen brackets fill a 12 × 12 × 8 in carton to just 16.8% density — the rest is air — at $0.081 per part. That is the baseline Stacking has to beat.
Part 1 | Value |
Part | Stamped steel bracket 11.4 × 9.7 × 1.9 in · 289 × 247 × 49 mm |
Material / weight | Steel, 1.4 lb |
Flexible Layering | Stacking | |
Box (in) | RSC 12 × 12 × 8 | RSC 12 × 12 × 8 |
Board grade | Single-wall C | Single-wall C |
Parts / box | 14 | 23 1.6× more |
Parts / truck | 28,560 | 30,360 |
Cost / part | $0.081 | $0.054 33% lower |
Switching to Vertical Stacking nests the same bracket at a tighter pitch: 23 per carton instead of 14, lifting pack density from 16.8% to 27.6%. The brackets are heavy enough that the truck hits its weight limit either way, so Stacking actually ships on fewer pallets (22 vs 34) — yet still moves more parts per truck, because each carton now carries so many more. The same fixed freight and packaging spread across all of them: $0.054 per part, 33% below the Flexible Layering baseline, in the identical box at the identical board grade.
Part 2 · a car door panel (returnable steel rack)
The second part is a stamped car door panel — a large curved sheet, about 50.7 × 38.5 in laid flat and only ~3 in deep, weighing 12 lb. Panels like this ride on a returnable steel rack rather than in a carton, and they nest face-to-face when stood on edge. Our baseline packs them with Planar Layering and Horizontal Nesting — 75 panels to a 52 × 48 × 58 in rack — at a recurring $0.577 per part (logistics + packaging; the rack fleet is costed separately). That is the number Stacking has to beat.
Part 2 | Value |
Part | Car door panel 50.7 × 38.5 × 2.9 in · 1288 × 978 × 74 mm |
Material / weight | Steel, 12 lb |
Container | Returnable steel rack, 52 × 48 × 58 in |
Part margin | 0.2 in on every side clearance for dunnage |
Planar Layering | Stacking | |
Rack (in) | 52 × 48 × 58 | 52 × 48 × 58 |
Parts / rack | 75 | 134 1.8× more |
Parts / truck | 1,800 | 2,948 |
Rack fleet | 59 | 33 |
Cost / part | $0.577 recurring (logistics + packaging) | $0.348 40% lower |
With Horizontal Stacking, Pack Studio stands the panels on edge and finds the in-plane heading that nests them tightest face-to-face: 134 to a rack instead of 75. Denser racks let the same 100,000-panel-a-year program circulate a smaller fleet — 33 racks instead of 59, dropping the up-front rack investment from $88,500 to $49,500 — and each truck now carries 2,948 panels instead of 1,800. The recurring cost falls to $0.348 per part, 40% below the Planar-Layering baseline.
Two parts, one lever. On the bracket and the door panel alike, stacking fit far more parts into the very same container — 1.6x and 1.8x as many — and cut the cost per part by 33% and 40%. Nothing about the parts, the containers, the truck, or the freight changed. Pack Studio optimizes for best cost advantages and better packing.
