A Yageo AC or KOA RK73H cross-reference for Mexican automotive EMS fails on temperature coefficient first. We counted Walsin’s 0805, 1 kilohm, 1 percent single resistors: 26 part numbers, 15 with an automotive series label, and only 1 of the 15 holds 50 ppm per degree. None of the 26 is on our Hong Kong shelf.
Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the chip resistor export of Walsin Technology (Walsin): 234,815 rows, 234,401 of them distinct part numbers. This post is for a procurement or design engineer at a Mexican automotive electronics manufacturing services plant whose bill of materials names a Yageo AC or KOA RK73H resistor and who wants a Hong Kong second source in small lots. Every Walsin part number below is real. Every count is ours. The Yageo number was opened on Yageo’s own page and the KOA series in KOA’s own document, both on 23 October 2026.
What do Mexico’s auto-parts figures say about demand for chip resistors?
They say a very large production base, and nothing about one resistor. Mexico’s Industria Nacional de Autopartes (INA), as reported by Cluster Industrial on 8 October 2026, put auto-parts production at 74.7 billion US dollars in January to July 2026, up 8.8 percent on the same period of 2025, with electrical parts the largest group at 14.5 billion US dollars. We read the report on 23 October 2026.
The same report gives auto-parts exports of 65.0 billion US dollars and imports of 43.3 billion US dollars for the seven months. It does not mention electronics components. We take no demand figure for resistors from it, and neither should you.
Our view, labelled as ours: a plant that builds electrical modules for vehicles is bound by its customer’s approved vendor list, so the question it asks of a second source is narrower than price. It asks which fields differ, in writing.
What do Yageo’s and KOA’s own pages say about an automotive 0805 1 kilohm line?
They say the incumbent is tighter on temperature coefficient than Walsin’s general-purpose automotive-labelled line. Yageo’s page for AC0805FR-071KL describes it as automotive grade thick film, lists AEC-Q200 under qualifications, and prints 1 kΩ, ±1%, 0.125 W at 70 °C, ±50 ppm per degree, 0805. KOA’s RK73H document lists 0805 (code 2A) among the sizes under its AEC-Q200 qualified heading, with a footer date of 27 January 2026.
| Incumbent | Source we opened | Fields read | Walsin general-purpose candidate | Match / mismatch |
|---|---|---|---|---|
AC0805FR-071KL (Yageo AC) |
Yageo specsheet page, generated 23 October 2026 | 0805, 1 kΩ, ±1%, 0.125 W, ±50 ppm, AEC-Q200 listed | WR08X1001FTLJ |
Match on size, value, tolerance, power and automotive label; mismatch on temperature coefficient (≦±100 against ±50) |
RK73H2ATTD1001F (KOA RK73H) |
KOA RK73H document, pages 23 and 24 | 0805 (2A), 1 kΩ, ±1%, AEC-Q200 qualified list includes 2A | WR08X1001FTLJ |
Match on size, value and tolerance; power and temperature coefficient not read, so the mismatch status is unknown |
We could not extract KOA’s power and temperature coefficient columns cleanly, so we do not state them. Read the 2A row in KOA’s own table. We did not open a KOA page for this exact number, so RK73H2ATTD1001F is built from KOA’s printed layout (size code, termination, packaging, three significant figures and a multiplier, tolerance letter) and is flagged below.
Which Walsin 0805 1 kilohm resistors carry an automotive label?
Fifteen of 26, and the label is not a prefix. We parsed all 234,815 rows and found 26 single-resistor part numbers at 0805, 1 kΩ and ±1%: 15 carry an automotive series label, and of those 7 start with W, 6 start with M and 2 start with S. A filter on the M prefix finds 6 of the 15 and misses 9.
The 8th-position tail also varies. On the three general-purpose W parts it is J, V or Z. Walsin’s WR approval sheet, as recorded in our working notes, reads J as AEC-Q200 compliant and V or Z as AEC-Q200 with anti-sulfuration. We hold the WR and MR datasheets, 2 of our 28, and none for the WF, WK or SR families.
| Walsin part | Series label in the export | Rated power | Temperature coefficient | On shelf 23 September 2026 | Match / mismatch against AC0805FR-071KL |
|---|---|---|---|---|---|
WR08X1001FTLJ |
General purpose (Automotive) | 1/8 W | ≦±100 | No | Match on power and label; mismatch on coefficient |
WR08X1001FTLV |
General purpose anti-sulfuration (Automotive) | 1/8 W | ≦±100 | No | Match on power and label; mismatch on coefficient |
MR08X1001FTL |
General purpose (Automotive) | 1/4 W | ≦±100 | No | Mismatch on power (twice) and coefficient |
MR08X1001FTR |
General purpose LF 100 ppm (Automotive) | 1/8 W | ≦±100 | No | Match on power and label; mismatch on coefficient |
SR08X1001FTL |
High grade anti-sulfuration (Automotive) | 1/4 W | ≦±100 | No | Mismatch on power (twice) and coefficient |
WF08K1001FTLJ |
High precision TC50 (Automotive) | 1/8 W | ≦±50 | No | Match on size, value, tolerance, power, coefficient and label; mismatch on family prefix |
MR08X1001FTL and MR08X1001FTR differ by one letter and by a factor of two in rated power, 1/4 W against 1/8 W. A buyer who reads the family name and not the row takes the wrong wattage. Our post on Walsin automotive chip resistors MR, SR and the AEC-Q200 split explains the prefix letters.
Which candidate keeps 50 ppm and an automotive label?
One, and it sits in the high-precision family. We counted the temperature coefficient column across the 26 parts: 23 print ≦±100 and 3 print ≦±50, and only WF08K1001FTLJ among the 3 carries an automotive series label; the other two, WF08K1001FTL and WK08K1001FTL, do not. We have not seen this pairing counted anywhere.
That one part matches Yageo’s printed fields on size, value, tolerance, power and temperature coefficient. It differs in family: WF is Walsin’s high-precision prefix, and the general-purpose automotive parts sit under WR, MR and SR. If your approved vendor list names the family as well as the fields, that is a conversation with your customer, not a cross we can settle.
Does a ≦±100 part belong on a line the incumbent holds to ±50? Only your circuit can say, and a divider or a current-sense path may care where a pull-up does not. We state the difference and leave the decision to you.
What do we hold in stock, and what do our documents say about AEC-Q200?
We hold none of the 26 in stock, and our documents say compliant, not certified. Our stock list as at 23 September 2026 holds 1,125 part numbers, and 0 of the 26 are among them; across all 82 part numbers at 0805 and 1 kΩ in every tolerance, we found none on the shelf.
Walsin’s own wording for its automotive parts is compliant. Yageo’s page lists AEC-Q200 under qualifications, and KOA’s document uses a qualified heading. Those are three different phrasings of three different statements, and none of them replaces the qualification report for the exact part number, which you should ask the maker for.
Venatech holds neither ISO 9001 nor IATF 16949. We also hold no PPAP or IMDS documents. If your Mexican customer requires them from every supplier, ask us before you place an order, and we will tell you plainly what we can and cannot provide. The ready stock page shows the Hong Kong snapshot, dated 23 September 2026, never live. Export and import rules, and any USMCA questions, are for your compliance team. We give no legal or customs advice.
How can Venatech help a Mexican automotive EMS plant?
By crossing the Yageo or KOA number you already use, stating every difference, and telling you what is missing. Venatech Limited is an authorised Walsin distributor in Hong Kong. Walsin is our only authorised line, and the other lines we supply are Stackpole and Viking.
- Cross-reference. Paste your Yageo, KOA, Vishay or Panasonic resistor number into the free cross-reference tool, which decodes 18 manufacturers’ part numbers across 800,000+ crossable parts, and read each Walsin candidate with match and mismatch stated field by field.
- BOM check. Upload a board bill of materials to /bom/ and have each line checked against the same engine.
- Ready stock. The ready stock list is a Hong Kong snapshot dated 23 September 2026, never live-synced.
- Service. Hong Kong-based, small lots, cross-referencing help, and a quote requested through the site. Our address is Unit 207, 2/F, Sun Ling Plaza, 30 On Kui Street, Fanling, N.T., Hong Kong, telephone (852) 2628 4777.
A worked example from our own export: AC0805FR-071KL, 0805, 1 kΩ, ±1%, 0.125 W, ±50 ppm, automotive grade, maps to WF08K1001FTLJ on every electrical field, and to WR08X1001FTLJ on every field but temperature coefficient. Both are factory orders. Our chip resistor range lists the families, and our post on crossing Yageo and Kemet chip resistors to Walsin covers the general method. Confirm against both datasheets and qualify in your own circuit.
The short version
Mexico’s auto-parts production was 74.7 billion US dollars in January to July 2026, per INA as reported on 8 October 2026. At 0805, 1 kΩ and ±1%, Walsin lists 26 single resistors, 15 with an automotive label, 1 of them at ±50 ppm, and none on our shelf.
Send us the Yageo AC or KOA RK73H lines from one automotive board and we will return the Walsin candidates with every difference stated. When the incumbent holds 50 ppm and the nearest automotive-labelled general-purpose part holds 100, which of your customer’s approvals names the field?
Sources
Fetched 23 October 2026. The market statement is taken from the first page. The incumbent values are those printed on the Yageo page and in the KOA document; those numbers are not in the Walsin export.
- Cluster Industrial, “Producción de autopartes en México supera los 74 mil mdd durante enero-julio de 2026”, 8 October 2026, citing INA: https://clusterindustrial.com.mx/produccion-de-autopartes-en-mexico-supera-los-74-mil-mdd-durante-enero-julio-de-2026/
- Yageo specsheet page for an AC 0805 1 kΩ number, not in the export: https://www.yageogroup.com/component-documentation/download/specsheet/AC0805FRE071KL
- KOA RK73H series document, pages 23 and 24, not in the export: https://www.koaspeer.com/pdfs/RK73H.pdf
Frequently asked questions
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How large was Mexican auto-parts production in early 2026?
INA, as reported by Cluster Industrial on 8 October 2026, put it at 74.7 billion US dollars for January to July 2026, up 8.8 percent on the year. Electrical parts were the largest group at 14.5 billion US dollars. The report does not mention electronics components.
How many Walsin 0805 1 kilohm resistors carry an automotive label?
Fifteen of 26 single-resistor part numbers at 0805, 1 kΩ and ±1%. Seven start with W, 6 with M and 2 with S, so a filter on the M prefix finds only 6 of the 15. The label sits in the series name in Walsin’s export.
Is there a Walsin automotive-labelled resistor at 50 ppm for AC0805FR-071KL?
One. WF08K1001FTLJ prints ≦±50 and an automotive series label, at 1/8 W, in the high-precision family. It matches Yageo’s printed fields on size, value, tolerance, power and temperature coefficient, differs in family prefix, and is not on our shelf.
Is Walsin’s automotive resistor AEC-Q200 certified?
Walsin’s wording is compliant, not certified. Yageo’s page lists AEC-Q200 under qualifications and KOA’s document uses a qualified heading. None of these replaces the qualification report for the exact part number, which you should request from the maker.
Does Venatech hold IATF 16949 or ISO 9001?
No. Venatech holds neither, and we hold no PPAP or IMDS documents. If your customer needs them from every supplier, ask us before ordering. We will say plainly what we can and cannot provide.
Can I place a small lot from Hong Kong for a Mexican plant?
Small lots are our normal service, requested through the site, and none of the 26 candidates is held as at 23 September 2026, so they are factory orders. We make no lead-time or price promise here. Import and USMCA questions are for your compliance team.