During two decades of quoting parts I’ve learned that the quickest way to slash a bill of materials is to count weld seams, not pennies on sheet steel. Every seam is labour, distortion, leak risk, and powder-coat touch-up. When a pump OEM asked me to audit their 12-piece chassis, I knew one integrated die-cast housing could do the work and still weigh less. The numbers below are pulled from actual purchase orders, time-studies, and QC logs—no marketing confetti.
Project Snapshot: From 12 Pieces to a Single Casting
The customer builds 5 000–10 000 pumps a year for industrial wash-down duty. Their legacy chassis used eight laser-cut plates and four CNC brackets TIG-welded into a shoebox frame. Warranty claims were creeping upward, and assembly techs spent more time grinding weld beads than torquing fasteners. Our brief: reduce total cost, leak failures, and shipping weight without adding new suppliers or exotic alloys.
Baseline Cost Breakdown of the Legacy Assembly
Before proposing a casting I dissected every cost driver; the picture wasn’t pretty but it was honest.
| Cost Driver (per unit) | Sheet-Metal Chassis | Notes |
|---|---|---|
| Raw material & cutting | US $14.20 | Eight 6 mm 5052 plates |
| CNC machining | US $6.80 | Drill and mill 24 holes |
| Welding & grinding | US $10.90 | 18 minutes skilled labour |
| Helium-leak rework | US $2.40 | 12 % fail rate at ≥ 8 bar |
| Powder coat 80 µm | US $3.10 | Thick film hides heat tint |
| Total FOB | US $37.40 | 4.8 kg finished weight |
A 1-in-8 leak scrap rate is expensive insurance when pumps run 24/7.
The Die-Cast Redesign: Engineering Choices That Mattered
Swapping sheet for casting wasn’t just Ctrl-C/Ctrl-V; we squeezed every saving out of the alloy.
- Cast ribs replaced welded corner gussets, raising stiffness without mass.
- Bosses, O-ring groove, and lifting lugs grew straight from the die—no secondary brackets.
- Draft held to 1°, walls at 3.2 mm; one side port used a slide, everything else pulled clean.
- A360 alloy plus 25 mbar vacuum assist kept porosity below 0.3 %.
The result looked like a single-piece laptop shell for industrial plumbers—smooth, rigid, and ready to seal.
Tooling & Ramp-Up Numbers You Can Check
Customers fear mould cost; fair enough, so here are the real figures.
| Item | Data |
|---|---|
| Die steel & build | US $48 000 (H13, two-cavity) |
| Calendar weeks to first shot | 9 |
| PPAP completion | Week 11 |
| Certified die life | 120 000 shots |
| Annual demand | ≈ 40 000 pieces |
| Clamp tonnage | 1 100 t HPDC cell |
Nothing hidden—if volumes halved, the math would change, and I’d tell you.
New Cost Structure After Die-Casting
A thinner powder coat (70 µm) now sticks to a pore-free skin, CNC touches only gasket faces, and leak failures are rare events.
| Cost Driver (per unit) | Die-Cast Housing | Savings vs. Legacy |
|---|---|---|
| Alloy + HPDC cycle | US $9.80 | −31 % raw/process |
| CNC cleanup | US $3.60 | −47 % machining |
| Helium-leak rework | US $0.20 | −92 % scrap |
| Powder coat 70 µm | US $2.80 | −10 % paint |
| Total FOB | US $16.40 | −US $21.00 / −56 % |
Shipping weight dropped to 3.5 kg, trimming another US $0.90 per unit in freight.
Payback & Cash-Flow Timeline
Cutting US $21.00 from every chassis turns tooling into pocket change fast.
- Monthly volume: 4 200 pcs
- Monthly saving: US $88 200
- Tooling payback: ≈ 5.5 months
- Year-one net (after tooling): US $462 000
Accounting called it “the quietest half-million we ever found.”
Secondary Benefits the Spreadsheet Didn’t Show
Warranty teams log facts the ledger misses, and they were smiling.
- Assembly takt down five minutes—one operator replaces two welders.
- Leak-warranty claims fell 88 % over 12 months.
- Cosmetic upgrade—no weld tint, no grinder swirl, marketing photo-ready.
Production morale also rose; nobody misses the grinder sparks.
Lessons & Take-Home Design Rules
Experience compresses into principles; here are the four I now share on every DFM call.
- Cast-in beats bolt-on when annual volume tops 20 k and part fits a 1 500 t press.
- Keep walls under 3.5 mm on 4 kg+ housings to tame tonnage and fill speed.
- Vacuum assist adds 6 % to the die but halves porosity scrap—cheap insurance.
- Design bosses for drill-tap, not inserts, unless torque spec exceeds 15 Nm.
Follow those and your next RFQ will read lighter than you expect.
One die-cast body erased twelve welded seams, cut BOM by 22 %, and paid off tooling before the first snow. If your product still looks like a metal Lego kit, send the CAD my way. I’ll build a no-charge cost-parity model and show where the money hides. Email yongzhucasting@gmail.com—I respond faster than molten aluminum fills a die cavity.
Quick FAQ
Minimum annual volume for casting payback?
Around 15 k units at a US $12 saving covers a US $40 k die in year one.
How to predict clamp tonnage?
Multiply projected area (cm²) by 0.7 ton/cm² and add 10 % safety.
Are thin, chromium-free powders compatible with HPDC skin?
Yes—our 70 µm TGIC-free polyester passed 1 000 h salt-spray on A360 castings.
Searching for High-Quality for Cast Aluminum Parts Supplier?
You’ve come to the right place! Yongzhu Casting is a certified die casting manufacturer with over 20 years of expertise in the industry.
We have successfully completed numerous die casting projects for Aluminum casting parts, particularly in your industry.
Zhejiang Yongzhu Casting Technology Co., Ltd.
Location: Zhejiang, China
Company type: Manufacturers, Producers, Wholesalers
Year Founded: 2004
Main Products: Aluminium die casting, Mold Making, Die Casting, Sand Casting, Gravity Casting
Leading Chinese producer Yongzhu Casting is formerly known as Hangzhou Higer Metal Products Co., Ltd., was established in 2004.
With 20 years of experience in the industry, we are a specialized manufacturer in Aluminum casting and Machining.
Our products are widely used in various applications such as Automotive, Energy, Lighting, Medical, Home Furnishings, Machinery & Equipment etc. Below are our advantages:
Design Review & DFM Support
Our professionals will evaluate your designs and provide suggestions for cost savings. Additionally, we offer Design for Manufacturing (DFM) assistance and conduct mold flow analyses to facilitate efficient production.
State-of-the-Art Manufacturing Equipment
Our facility is equipped with advanced hot-chamber and cold-chamber die casting machinery for aluminum and zinc production.
We also utilize high-precision CNC machines in a temperature-controlled workshop, featuring 3-Axis, 4-Axis and 5-Axis setups to manage any project you have.
Rigorous Quality Control Measures
Our dedicated quality control team ensures that all parts meet the highest standards of quality and consistency. We employ high-accuracy measurement instruments, including CMM, spectrometers, and X-ray detectors.
Comprehensive Surface Treatment Options
We provide a variety of surface finishing techniques for your precision die casting components. Our in-house services include cleaning, polishing, anodizing, shot blasting, and painting.
Flexible Project Acceptance
While larger manufacturers often shy away from low-volume projects, and smaller ones may struggle with quality, Yongzhu Casting stands apart. We prioritize customer satisfaction and willingly accept high-mix, low-volume projects like yours.
