I manage procurement for a 120-person defense subcontractor. Each quarter, I place orders for about $180,000 in passive components—capacitors, resistors, inductors. Over the past 6 years, I've documented over 500 orders in our cost tracking system.
Here's the thing nobody tells you about sourcing Kemet components: the CAGE code isn't just paperwork. It's your first line of defense against counterfeit parts. And if you're buying T491 series tantalum capacitors for a project that can't fail, skipping this checklist could cost you more than money.
Here are 6 steps I use for every high-stakes component order. The last step is the one I learned the hard way.
Who This Checklist Is For
Use this when:
- You're sourcing Kemet components (CAGE code 2780) for a regulated industry (aerospace, medical, defense)
- You need to verify the part is authentic—not a relabeled reject
- You're comparing Kemet T491 series against competitors like AVX or Vishay
- Your customer requires traceability back to the manufacturer
If you're just ordering parts for a prototype or personal project, you can skip steps 3–6. But for anything that goes into production? Don't.
Step 1: Verify the CAGE Code—Don't Trust the Label
What to do: Look up CAGE code 2780 in the official DLA (Defense Logistics Agency) database. Not a third-party site—the actual cage.dla.mil portal.
Why: Counterfeiters print fake Kemet labels with the correct CAGE code. But they can't change the DLA registration. I've seen a batch of capacitors labeled "Kemet, CAGE 2780, T491" where the code checked out—until I checked the DLA record and found the registered address didn't match the shipping origin. The parts were from a different facility entirely.
Checkpoint: The CAGE code 2780 entity should resolve to Kemet Corporation (now Yageo Corporation subsidiary). Verify the physical address matches what's on your supplier's documentation.
Step 2: Cross-Reference the Kemet Part Number Against CAGE 2780
What to do: Not every Kemet-labeled part is manufactured under CAGE 2780. Some distributors slap the Kemet name on non-Kemet parts. Go to Kemet's official site or their authorized distributor portal. Enter the full part number—T491, T520, whatever series—and check the CAGE code associated with that specific line.
Why: Counterfeiters are getting smarter. They buy genuine Kemet parts for one series, then use the same label design for a different series they sourced elsewhere. I caught a batch of T491 parts that had the correct CAGE code on the label but the actual part didn't match Kemet's datasheet dimensions. Turned out they were relabeled generic capacitors from an unknown factory.
To be fair, this is rare. But when it happens, the redo cost is painful. I've seen a $4,200 order turn into $12,000 because the counterfeit parts failed during testing.
Step 3: Check the Date Code—It's Not Optional
What to do: Kemet date codes follow a standard format (e.g., YYWW). Verify the code on the part matches the label. Then check if the parts are within their shelf life—tantalum capacitors have a recommended storage period, usually 2–3 years from manufacturing.
Why: Older parts can have degraded moisture sensitivity. I almost approved a batch of T491 series with a 3-year-old date code because the price was 15% below market. Good thing I checked—those parts had a known soldering reflow issue documented in Kemet's technical bulletin. Using them would've meant rework costs exceeding the supposed savings.
In my opinion, date code verification is the most underrated step. It's not just about freshness; it's about avoiding known manufacturing defects that were corrected in later production runs.
Personal rule: If the date code is more than 18 months old, I fire a red flag. I've done that and still found parts that passed testing. But I'd rather waste time verifying than skip it and pay later.
Step 4: Compare Physical Dimensions to the Datasheet
What to do: For every new lot, pull a random sample and measure it. Length, width, height, lead spacing. Compare to the official Kemet datasheet for that specific part number.
Why: I've seen three scenarios where this matters:
- Counterfeit parts: Sometimes they use a different case size because the fake is built on a generic base.
- Obsolete series relabeled: A supplier cleans up old stock, relabels the T491 as a newer series, and sells it at a premium.
- Manufacturing variance: Kemet's tolerances are tight. If your measurement falls outside their spec, you're holding a non-compliant part—whether it's genuine or not.
This step feels tedious. It is. But I'd argue it's the cheapest insurance you can buy. A digital caliper costs $20. A batch of bad capacitors costs thousands in rework and lost time.
Step 5: Trace the Supply Chain—Back to CAGE 2780
What to do: Ask your supplier for the chain of custody. You want to see: Kemet (CAGE 2780) → Authorized Distributor → Your supplier → You. Every step should have documentation.
Why: The most common failure point I've seen isn't counterfeit parts from China. It's gray-market parts that enter the legitimate supply chain, then get sold as "genuine Kemet" without proper traceability. These parts are often real Kemet—but they were surplus, overstock, or even rejected parts that leaked out of the authorized channel.
I learned this after a $4,800 order of T491 capacitors. The supplier had a great price. The labels looked perfect. The CAGE code checked out. But when I needed a certificate of conformance (CofC) for an audit, the supplier couldn't produce one from Kemet's authorized channel. The parts were real—but untraceable. My customer rejected the whole lot.
Net loss: $4,800 plus $1,200 in rush reordering from an authorized distributor. That's a 25% premium I could've avoided.
Step 6: Order a Small Sample Batch First (The One I Learned the Hard Way)
What to do: For any new supplier or new series, don't place the full order upfront. Order 10–25 pieces. Test them—electrically and mechanically—before committing to the full quantity.
Why: This is the step I skipped once, and it cost me. Had 2 hours to decide before a deadline for rush processing. Normally I'd have time to sample, but there was no room. Went with a supplier I'd used before based on trust alone.
In hindsight, I should have pushed back on the timeline. But with the project manager waiting, I made the call with incomplete information.
The parts passed visual inspection. They passed the CAGE code check. They even matched the datasheet dimensions. But when we ran them in production, 6% failed during reflow. The failure mode was subtle—intermittent opens that only showed up under thermal stress. By the time we caught it, we'd already placed them on 40 boards.
The rework cost $1,200. The "saved" $450 in rush fees? Swallowed up entirely.
Current policy: Any order over $2,000 gets a 10-piece sample test. It's added 3 days to our lead time on average. But it's cut our rework rate from 8% to under 0.5%. In my opinion, that's a trade-off worth making every time.
Common Mistakes to Avoid
- Relying only on CAGE code: CAGE 2780 confirms Kemet Corporation exists. It doesn't confirm the specific part in your hand is from them.
- Skipping date codes: Old parts aren't inherently bad, but they need extra scrutiny. Don't assume.
- Trusting "authorized distributor" status blindly: Some distributors authorize multiple channels. The one you're buying from might not be the one Kemet directly supplies.
- Ordering full quantity without sampling: I get why people do it—deadlines are real. But the risk isn't worth the time savings. Not once in my experience.
As of January 2025, Kemet's CAGE code 2780 remains active. Verify current pricing at kemet.com or through an authorized distributor, as rates may have changed since this writing.
