There is a large difference between buying a finished product from an Asian factory and buying the pieces that go into one. When you buy a finished product, one supplier owns the outcome. When you source components — a motor here, a resin there, connectors from a third vendor, a display from a fourth — you own the outcome, and every gap between what you thought you specified and what actually arrives lands on your line, not theirs.
Component sourcing from Asia can cut a bill of materials substantially, sometimes 30–60 percent against Western distributor pricing on commodity parts. It also introduces failure modes that do not exist when you buy from an authorized distributor at home. Knowing which parts belong in which channel is most of the skill.
Start With a BOM That Can Be Sourced
Sourcing goes wrong before the first RFQ if the bill of materials is loose. Every line needs a manufacturer part number, not a description; a specified material grade, not a family name; and an explicit note on whether alternates are acceptable. "ABS black" is not a specification — ABS from different compounders varies in impact strength, flow, and UV behavior by a wide margin. Our guide to building a bill of materials covers the structure, and grade-level detail on plastics and metals matters far more than most founders expect.
Mark each line with a criticality class. A safety-critical part, a regulated part, or a part whose failure returns the product to you is not a candidate for the cheapest listing on a marketplace. A shipping carton, a bag of M3 screws, or a silicone foot is.
Where the Channels Split
| Part type | Buy from Asia | Buy from authorized distribution |
|---|---|---|
| Fasteners, gaskets, cables, enclosures, packaging | Usually yes — big savings, low risk | Only for tiny quantities |
| Passives, connectors, LEDs, common power parts | Yes, from established manufacturers with catalogs and datasheets | When traceability is required |
| Microcontrollers, memory, power management, RF modules | Risky — this is where counterfeits live | Strongly preferred |
| Lithium cells, mains-voltage parts, medical-contact materials | Only with full certificates and audited suppliers | Default |
The line is drawn by consequence, not by price. A fake resistor costs you a rework. A fake power MOSFET or a re-marked microcontroller costs you a field failure, and possibly a recall. The tactics for keeping those out of your build are in our article on counterfeit electronic components.
Vetting a Component Supplier
The vetting workload is different from vetting an assembly factory. You are checking a distribution and quality chain, not a production floor.
- Ask for the chain of custody. Where did this lot come from? Authorized distributor, factory direct, or open market? A supplier who cannot answer is an open-market broker regardless of what the website says.
- Demand documentation per lot. Certificate of conformance, material data sheet, RoHS and REACH declarations, and date codes. For metals and plastics, a mill certificate or resin lot certificate.
- Order samples before volume, and test them. Not just fit — measure. Weigh a bag of screws, section a cable, run a resin through a melt flow check if the part is structural.
- Check the pricing sanity. A part priced at a third of everyone else's price during a shortage is not a bargain. It is a story.
- Buy a second source from day one for anything with a long lead time. Single-sourcing is how a small hardware company loses a quarter, as our piece on planning around component shortages lays out.
Raw Materials Are a Different Animal
Resin, sheet metal, aluminum extrusion, silicone, foam, textiles, and adhesives are usually bought by your contract manufacturer, not by you. That is convenient and it is also the single most common place where cost gets quietly removed from your product. A factory told to hit a target price will find that price in the material bin first — a filled resin instead of a virgin one, a thinner gauge steel, a cheaper adhesive with a lower service temperature. The defense is naming the material and its supplier in the contract, requiring lot certificates, and spot-checking incoming material yourself. The mechanics are covered in stopping a factory from swapping in cheaper material and in incoming quality control.
The Landed Cost Nobody Quotes You
A component quoted at $0.42 ex-works is not a $0.42 component. Add ocean or air freight, duties under the applicable tariff line, customs brokerage, insurance, domestic freight, payment fees, inspection, and the carrying cost of the minimum order quantity you had to accept. On small parts, the minimum order is usually the dominant term: a $0.42 connector with a 10,000-piece minimum ties up $4,200 and a shelf, and if you revise the design you scrap it. Model landed cost per line before you commit, and be honest about the working capital. Duty exposure in particular has moved a lot in recent years — see US import duties and tariffs on products made in China.
The Hybrid Approach Most Companies End Up With
A very common and sensible pattern is to buy mechanical parts, enclosures, cables, and packaging from Asia while keeping semiconductors and safety-critical parts in authorized Western distribution, then assemble domestically or at a trusted CM. It preserves most of the cost advantage while keeping the risky lines traceable. If final assembly happens stateside, there are also country-of-origin and duty implications worth understanding early — our article on importing parts and assembling in the USA walks through them.
Manage Change, Not Just Purchase
Components go end-of-life, get re-spun, or change internally while keeping the same part number. Subscribe to product change notifications where the manufacturer offers them, keep a dated record of the exact part revision you qualified, and treat any substitution as an engineering change with a test plan attached — not a purchasing decision. Our guide on what to do when a component goes end-of-life covers the options once it happens.
Projects House builds and manages component supply chains for US product companies — writing sourceable BOMs, qualifying suppliers, running incoming inspection, and keeping second sources alive. If you want help getting your parts list off the spreadsheet and onto a reliable supply base, get in touch through our contact form.