I’ve been on both sides of this. I manufacture in China, and I’ve seen importers get burned. Here’s how to not be one of them.
Visit the factory. The number of people who place $50K orders based on Alibaba photos and a video call is insane. Photos can be stolen. Video calls can be staged. Walking through a production line — you can’t fake that.
Ask for material certs before samples. A real manufacturer has EPDM certs from their compound supplier, NSF listing numbers you can verify online, ROHS and REACH reports from accredited labs. If your supplier hesitates on any of these, walk away.
Don’t chase the lowest price. There’s always someone cheaper. The difference between a $0.35 seal and a $0.52 seal is usually the material. The cheaper one is SBR that fails in five years. You can’t see the difference in a photo. Get the paperwork.
Start small. Order 500 before you order 50,000. A $500 test order is way cheaper than a $50K mistake.