Custom Automotive Blow Molds ｜ Full-Service Manufacturing – Booling
- ISO 9001:2015
- Trusted by Tier 1
- DFM + Moldflow Simulation Included
- Quote Within 1 Working Day
- CMM Inspection Report with Every Mold
Automotive Blow Molds Manufacturing
Booling specializes in custom extrusion blow molding for automotive hollow components. We turn sophisticated CAD designs into mass-production-ready products. By integrating DFM analysis, mold flow simulation and precision machining, we ensure your molds run smoothly in production.
Performance Comparison
| Mold Type | Extrusion blow, two-half split construction |
| Parting Line | Straight or 3D-optimized curved surface (CAD designed) |
| Wall thickness tolerance | ±0.15 mm (verified by ultrasonic scanning) |
| Surface Finish | Polished to Ra 0.4 / VDI 3400 texture available |
| Cavity Inspection | Each mold ships with a CMM report |
| Mold Life | 300K–500K (P20) / 800K+ (S136) / 1M+ (H13 with nitriding) |
| Lead Time | 50–70 days for standard molds; 45 days for rush air-duct jobs |
| Deliverables | Full mold assembly + CMM report + maintenance manual + spare parts kit |
Mold Steel for Automotive Blow Mold
P20
P20 is pre-hardened, machines cleanly, and costs about half what stainless runs. We keep it in stock. For prototype molds or production runs under 200,000 shots where surface finish isn’t critical, it’s the right call most of the time — no need to spend more than the job demands.
Real-world range: 300,000 to 500,000 shots. Caveat: if your cooling channels are undersized and the mold runs hot, you’ll see wear earlier. That’s a design problem, not a P20 problem.
S136
S136 has around 13% chromium. We spec it when the material being processed is corrosive — HDPE off-gasses acetic acid, and past 500,000 shots that acid will pit standard P20. S136 doesn’t. It also holds a mirror polish better, which matters for fuel tanks and any part where surface integrity affects the end product.
It costs more and machines slower, so we don’t call for it unless the job actually needs it. Plenty of shops push stainless because the margin is better. We don’t.
Real-world range: 800,000+ shots. We’ve pulled S136 cavities at 900,000 that looked nearly new.
H13
H13 is built for thermal fatigue. On a continuous line where pinch-off zones are cycling between 200°C and 40°C every 45 seconds, H13 takes that thermal shock without micro-cracking. We use it for pinch-off inserts and high-wear sliding components — not the full cavity, because that’s overkill and adds cost with no real benefit.
With gas nitriding (0.2–0.3mm case depth, 900–1,000 HV surface hardness), H13 inserts routinely clear a million shots. We had an automotive fuel tank mold running in Mexico that hit 1.1 million before the first insert came out.
Real-world range: 1,000,000+ shots with nitriding.
Flame Retardant Plastic 3D Printing
Xometry’s 3D Print Service offers a variety of polymers that are flame retardant and qualify for UL-94 V-0 and FAR 25.853 60 second burn test. This includes FDM ULTEM 9085, FDM ULTEM 1010, and SLS Nylon 12, Flame Retardant. These polymers are perfect for aviation and aerospace applications.
Upload your CAD models today, and our engineering team will run a complete DFM and mold flow simulation for you. Let’s catch the thinning and stretching risks before the tool hits the CNC machine.
Automotive Blow Molds We Build
Automotive Water Filler Pipe Mold
Air Duct And HVAC Blow Mold
Automotive Rear Spoiler Mold
Automotive Side Step Mold
Automotive Roof Rack Mold
Mold Manufacturing Process
DFM Report
Last year we had an order from an overseas automotive parts supplier. It was an odd‑shaped air duct. The planned annual volume was roughly 80,000 pieces.Our engineers ran a CAE simulation and caught something early - at a sharp corner, the parison would stretch too much, which could cause local thinning or even cracking.We fixed the design before any steel was cut.In the end, the customer’s T1 samples passed on the first try. They got good samples seven days ahead of schedule, and we saved them material and labor costs on two extra trial runs.
3D Mold Design
We fully model the cavity, core, cooling lines, and split mechanisms. All design files go to you for final approval before machining starts. No hidden surprises.
Precision Machining
Our whole shop runs on high‑precision equipment. Roughing → finishing → fine polishing. Step by step. We control overall tolerances tightly.
Assembly And Polishing
Sliders, blow pins, cooling manifolds – we put it all together. Cavities get surface treatment per your spec. We also do dye penetration testing on the parting lines to make sure the mold closes tight.
T1 Sampling And CMM Inspection
First samples (T1) get run on a blow molding machine. Then a CMM compares key dimensions against your 3D model and drawings. We ship the samples together with the inspection report
Compatible Materials
| Materials | Value / Description |
|---|---|
| HDPE | Air ducts, oil tank, filler pipes, general hollow parts. The most widely used resin in blow molding. |
| PP+GF | Structural parts, side step covers, and similar components. |
| ABS | spoiler roof, interior and exterior hollow trim pieces. |
| PA+GF | 3D pipe, intake air duct |
