To be a valuable global supplier
for metallic honeycombs and turbine parts
I work at Maanshan MAT Aviation Manufacturing Co., Ltd. We make metal honeycomb substrates for catalytic converter. Most of what we ship is pretty standard – round, 400 cpsi, aluminum foil. That's what 80% of the market wants.
But the other 20%? That's where it gets interesting.
We get orders from all over. Europe, North America, Southeast Asia, the Middle East. And a lot of those customers don't want standard parts. They want something weird. Oval. Rectangular. D‑shaped. High cell density. Thick foil. Stainless instead of aluminum. Something that fits a space that wasn't designed for a converter in the first place.
We do that. It's not easy. But we've been at it long enough to know how.
Why Custom?
Most of the time, custom happens because the original equipment engineers painted themselves into a corner.
They designed the engine bay, the chassis, the exhaust routing. Then they realized they needed a catalytic converter. And the only space left was some odd‑shaped hole between the frame rail and the transmission.
Or they need a converter that flows more than a standard size – but can't be longer because it won't fit. So they go wider. Or oval. Or they need higher cell density for tighter emissions, but the space is the same.
We had a customer from Germany once. They needed a substrate for a diesel generator that had to fit inside a soundproof enclosure. The only space was a rectangular cavity, 150mm by 200mm. We made them a rectangular substrate. 300 cpsi, stainless foil. Worked perfectly.
Another customer from the US – a classic car restomod. They were putting a modern V8 into a 1960s muscle car. The engine bay was tight. They needed a converter that was flat on one side to clear the steering box. We made a D‑shaped substrate. First one we'd ever done. They sent us a drawing, we built the tooling, and it fit like a glove.
What We Can Change
When a customer says "custom," they can mean a lot of different things.
Shape. Round is easy. Oval, rectangular, D‑shaped, trapezoid – we've done them all. The more complex the shape, the more tooling time. But we can do it.
Cell density. Standard is 400 cpsi. We go down to 200 for dirty exhaust, up to 600 for high‑efficiency applications. 800? We've done a few.
Foil thickness. Standard is 0.05 mm. Thinner for fast light‑off. Thicker for heavy‑duty. Up to 0.1 mm.
Material. Aluminum for most cars. Stainless 316L for marine, coastal, or high‑heat. Sometimes other alloys for really nasty conditions.
Length. Longer substrate means more surface area, but more backpressure. We can cut to any length the customer needs.
Coating. Different precious metal loadings. Different washcoat formulations. We don't do the coating ourselves – we work with coating partners. But we can spec whatever the application needs.
Mounting mat. Different densities, different temperature ratings. We match the mat to the job.
The customer sends us a drawing – or just a sketch on a napkin – and we figure out the rest.
The Tooling Challenge
The hardest part of custom work is the tooling.
Round substrates are easy. We have forming rolls for standard diameters. Need a different diameter? We can wind it on a different mandrel. No big deal.
But oval or rectangular? That requires custom forming rolls. The corrugated foil has to be cut to a specific width, then stacked in a fixture that matches the shape. The fixture has to hold everything square during brazing.
We build our own tooling in‑house. That's key. If we had to outsource every fixture, custom work would take months and cost a fortune. Because we do it ourselves, we can turn around a custom shape in a few weeks.
I remember a customer from Thailand who needed an oval substrate for a bus. They sent us a can – just the empty shell – and asked if we could match it. We measured the can, designed the tooling, built the fixture, and shipped the first batch in four weeks. They've been ordering from us ever since.
Small Batches vs. Large Production
Custom work is almost always small batches. A customer might need 50 pieces for a prototype run. Or 200 for a niche vehicle. Or 1,000 for a fleet upgrade.
We don't have a minimum order quantity for custom shapes. If you need 10, we'll make 10. The tooling cost is the same whether you order 10 or 1,000, so the per‑part price is higher for small batches. But we'll do it.
We also do large production runs of custom parts. If a customer has a long‑term contract for a non‑standard substrate, we can ramp up. We've shipped tens of thousands of custom substrates to a single customer over several years.
The key is communication. Tell us what you need, how many, and when. We'll tell you if we can do it and what it will cost.
Quality Control for Custom Parts
Custom parts get the same quality checks as standard parts. Maybe more.
We check cell dimensions on every batch – even if it's a weird shape. We have gauges for oval cells, rectangular cells, whatever.
We do peel tests on every batch. Sacrifice one part, peel it apart. Make sure the brazing is solid.
We do flow tests. Even a D‑shaped substrate has to flow within spec.
We do light tests. Shine a light through the substrate. Look for crooked cells or blockages.
We measure every part. Length, width, thickness. For custom shapes, we often build a go/no‑go gauge that matches the customer's can.
If a custom part doesn't fit the customer's assembly, it's not just a bad part – it's a wasted order. We take that seriously.
Shipping to Global Markets
We ship substrates all over the world. Europe, North America, South America, the Middle East, Southeast Asia.
Different markets have different requirements.
European customers often want stainless foil and higher cell density. Their emissions standards are tight.
North American customers vary. Some want cheap aluminum. Some want premium stainless. Depends on the application.
Southeast Asian customers – lots of diesel, lots of heat. They need durability.
We package substrates carefully. They're fragile before they're canned. Foam padding, strong boxes, pallets. We've shipped tens of thousands of parts overseas with very few damage claims.
Lead times vary. For standard parts, we can ship within two weeks. For custom parts, figure four to six weeks for the first batch – tooling takes time. Repeat orders are faster.
Why Customers Come to Us
I think the main reason customers from overseas keep coming back is that we listen.
We don't just say "yes" to every request and then ship something close. We ask questions. What's the application? What are the temperatures? What's the duty cycle? What can size? What emissions standard?
If we think a customer's spec is wrong – maybe they're asking for aluminum in a marine environment – we tell them. We'd rather lose a sale than sell something that fails.
We also don't hide behind email. When a customer has a problem, they can call us. We have English‑speaking staff. We'll get on the phone and figure it out.
And we keep records. When a customer orders a custom shape, we save the tooling and the process settings. The next time they order, we don't have to start from scratch.
A Few Examples
We made a rectangular substrate for a generator manufacturer in Brazil. The generator ran on natural gas, high heat. They needed stainless foil, 300 cpsi, extra‑thick walls. We built the tooling, made a sample batch, tested it. They've ordered three more batches since.
We made an oval substrate for a boat builder in Florida. Marine environment, salt water. Aluminum wouldn't last. We used stainless 316L. The customer said it was the only converter that survived more than a year in their test boat.
We made a D‑shaped substrate for a specialty vehicle builder in Australia. The vehicle had a tight engine bay. They sent us a cardboard template. We built the substrate to match. They said it fit perfectly.
Custom size and structure catalytic substrates are a big part of what we do at Maanshan MAT Aviation Manufacturing Co., Ltd.
We make round, oval, rectangular, D‑shaped. Different cell densities, foil thicknesses, materials. Small batches or large. For customers all over the world.
It takes tooling. It takes time. But we've been doing it long enough to know how to do it right.
If you need a standard substrate, we have those too. But if you need something that doesn't come off the shelf – send us a drawing. Or a sketch. Or just a description of the space you're trying to fill.
We'll figure it out. That's what we do.