Walsin ID: An Internal Part ID in 1 of 203 Export Files, Covering 173 of 359,135 Part Numbers

Walsin ID is the only internal part identifier Walsin publishes, and we counted where it reaches: 1 of 203 export files, 173 of 359,135 distinct part numbers. On those 173 it is one-to-one with the part number, 173 values for 173 parts. It is also useless as a join key, and we will show you why.

Venatech Limited, an authorised Walsin distributor in Hong Kong, holds all 203 of Walsin Technology (Walsin) parametric export files and 28 Walsin datasheets, 451 pages. This post is written from 00_ALL_MLCC_combined.xlsx, the 173-row enriched MLCC extract, measured against the 24,026-row 00_ALL_MLCC_parts_combined.xlsx and the header rows of all 203 files. Every part number below is real and checked against our master list. If you are building a cross-reference tool, an ERP mapping or a second-source table, this is the column you will be tempted to use as a key, and this is the measurement that says do not.

What is the Walsin ID column and how many parts carry one?

A plain integer, present on 173 rows and nowhere else in our extract. We opened the header row of all 203 Walsin export files and searched for the column name. Walsin ID appears in exactly one file, the 173-row enriched MLCC extract, alongside ECD URL and DataSheet URL, which are also 1 of 203. The full 24,026-row MLCC export carries none of the three. Against the 359,135 distinct part numbers our 203 files hold once the known QA test row is excluded, that is 0.048 percent coverage.

The values run from 1 to 152,567. We counted the digit lengths: 6 rows carry a single-digit ID, 5 carry two digits, 11 carry three, 69 carry four, 81 carry five and 1 carries six. A field whose legal values include both 1 and 152567 is not a fixed-width code, which rules out every parsing convenience you would want from an identifier.

Is the Walsin ID one-to-one with the Walsin part number?

Yes, on every row that carries one. We counted distinct values in the Walsin ID column: 173 values across 173 rows, with no repeats and no blanks. We then counted distinct part numbers in the same 173 rows and got 173. The mapping is clean in both directions inside this file, and that is the one genuinely good thing we can say about the column.

That matters because the part number is not always clean. 00_ALL_MLCC_parts_combined.xlsx holds 24,026 rows and only 23,601 distinct part numbers, so 425 rows restate a string that already appears — a defect we measured separately in Walsin MLCC duplicate part numbers, 132 of 8,330. Where a part number is duplicated, a unique internal ID is exactly the thing that would resolve it. The ID is not in that file.

Can you derive a Walsin ID from a part number, or a part number from an ID?

Neither, and we tested both directions. There is no series prefix, no case-size digit and no check digit anywhere in the value, and no Walsin datasheet in the 451 pages we hold explains the field — we checked the MLCC index, INDEX_MLCC_series.csv, and the ordering key on page 2 of 11_Automotive_MT.pdf, and neither mentions an internal identifier. The MT automotive rows hold IDs 9,053 to 9,063 and the MG automotive rows hold 8,807 to 8,817 — adjacent blocks, different series, nothing in the number saying which is which. The eleven general-purpose 0201 rows in the sample hold IDs 1 to 19 with eight gaps, so even inside one series and one case size the integers are not consecutive.

Six of the sixteen series in the extract occupy a contiguous block of eleven IDs: MT, MG, big sizes, high Q HH, microwave RF and ultra-small 01R5. Ten of sixteen do not. The feed-through FT series is the extreme case: eight rows spanning IDs 20,214 to 152,567, a span of 132,354 for eight parts, with FT15X435M4R0 sitting alone at the top. A reader who assumes an ID range maps to a series will pull the wrong 132,346 parts.

Does sorting by Walsin ID keep a series together?

On thirteen of sixteen series, yes. On three, no. We sorted each series by Walsin ID and compared the resulting part-number sequence against a plain alphabetical sort of the same part numbers. The two orders agree on 13 of 16 series and disagree on three: automotive soft-termination ST, feed-through FT and low-profile TT. We have not seen this counted anywhere.

Look at the ST row. ST18B473K500 holds ID 20,038 and ST18B222K500 holds 23,407, yet alphabetically ST18B222K500 comes first. The ID is an insertion-order key — it records when Walsin added the part, not where the part sits in the range. That is a perfectly reasonable thing for a manufacturer’s internal system to do, and a trap for anyone treating it as a catalogue index.

Will a Walsin ID survive a BOM paste or an ERP field?

It survives the paste and loses the meaning. The ID is numeric with no leading zeros in any of the 173 values, so unlike a Walsin part number it will not be mangled by a spreadsheet’s type inference — the problem we set out in why Walsin part numbers do not paste into your BOM. What it will do is sit in your ERP looking like a quantity. Six of the 173 IDs are a single digit, including 1, 2 and 3, which belong to 0201B102K160, 0201B222J100 and 0201B222K100.

There is a second problem, and it is the one that matters commercially. An internal ID has no contractual standing. You cannot raise a purchase order against ID 9,053, you cannot put it on a drawing, and no second source can read it. The orderable string for that part carries a termination code and a packaging code that the export omits entirely — see Walsin CT-suffix orderable part numbers.

What should you put in your ERP instead of a Walsin ID?

The full orderable part number, with the suffix, plus the case size and thickness as separate fields. The specification string alone is not unique in the export — 425 rows of 24,026 restate one — and the ID that would disambiguate them reaches 173 rows.

1. Record the orderable code, not the catalogue code. Ask us for the termination and packaging suffix for your exact part number and store the whole string. We hold 28 Walsin datasheets, 451 pages, and will send the one covering your part.
2. Cross the whole list in one pass. Paste up to 500 part numbers or drop your Excel or CSV into the free cross-reference tool. It decodes 18 manufacturers’ part numbers against 800,000+ crossable Walsin part numbers, and every difference from your original is stated rather than hidden. We will not tell you a part is equivalent. We will show you where it differs.
3. Check what is physically in Hong Kong on ready stock — 1,125 part numbers as at 23 September 2026, a dated snapshot and not a live feed.

The full range sits on the Walsin MLCC page. Our line runs from Hong Kong, Shenzhen, Singapore and Jiangmen, with Chengdu in preparation, and nowhere else. Unit 207, 2/F, Sun Ling Plaza, 30 On Kui Street, Fanling, N.T., Hong Kong. (852) 2628 4777.

The short version

Walsin ID is one-to-one with the part number on all 173 rows that carry it, and that is the whole of its usefulness. It appears in 1 of 203 export files and covers 173 of 359,135 distinct part numbers, 0.048 percent. Its values run from 1 to 152,567 with no prefix, no fixed width and no check digit, so nothing in the number tells you the series. Six of sixteen series sit in a contiguous block of eleven; the feed-through series spans 132,354 for eight parts. Sorting by ID reproduces part-number order on 13 of 16 series and breaks it on three. Six IDs are a single digit. Meanwhile the full export, which has no ID column at all, restates 425 of its 24,026 part numbers. Qualification stays with you, and so does the decision about what your ERP actually keys on.

Send us the Walsin lines off your bill of materials and we will return the full orderable code for each one, with the suffix the export drops, so your ERP holds a string you can buy against. And a question back: if your system’s unique key for a passive part came out of a supplier spreadsheet, has anyone checked how many rows that spreadsheet covers?

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