MLCC Tolerance Codes by Dielectric Class: 16 of Walsin’s 8,480 Class II Rows Beat ±5%, Counted for Sweden

We read the MLCC tolerance code out of all 24,026 part numbers in Walsin’s MLCC export and split them by dielectric class. Class I holds 15,546 rows and uses 11 of the 13 codes. Class II holds 8,480 rows and 16 of them beat ±5%. We have not seen this counted anywhere.

---

Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the full parametric export for Walsin Technology (Walsin) MLCC — 00_ALL_MLCC_parts_combined.xlsx, 24,026 rows — plus 26 MLCC datasheet PDFs and the index INDEX_MLCC_series.csv. For this post we took the tolerance character out of each part number ourselves, rather than trust the Tolerance column, and counted the result against dielectric class and case size. Every part number below is real.

How many MLCC tolerance codes does Walsin actually use, and which dielectric class gets which?

Thirteen codes, and the two classes barely overlap. We read character nine of all 24,026 part numbers. Class I — NP0 and X8G, 15,546 rows — uses eleven of the thirteen. Class II — X7R, X5R, X6S, X7S, X8R, X7T and Y5V, 8,480 rows — uses eight. Only six codes appear in both.

Code	Tolerance it denotes	Class I rows	Class II rows
P	±0.02 pF	53	0
Q	±0.03 pF	33	0
A	±0.05 pF	1,099	0
B	±0.1 pF	2,536	2
C	±0.25 pF	2,123	0
D	±0.5 pF	872	0
F	±1%	1,834	8
G	±2%	1,777	6
J	±5%	4,034	1,689
K	±10%	1,174	5,107
M	±20%	11	1,651
V	−10% / +7%	0	2
Z	−20% / +80%	0	15

Five codes are Class I only: P, Q, A, C and D, the absolute-picofarad grades. Two are Class II only: V and Z, the asymmetric ones. 99.6% of Class II rows — 8,447 of 8,480 — carry J, K or M, which is ±5%, ±10% or ±20%. In the other direction, Class I carries ±20% on just 11 rows out of 15,546.

P and Q are the narrowest grades in the catalogue and they exist at two case sizes only, 0201 and 0402, across 86 rows: 8 in the RF series and 78 in the UF series. RF15N0R1P500 and UF15N0R1P500 are 0.1 pF NP0 parts at 0402 and 50Vdc, from WTC_MLCC_Microwave_RF.pdf and WTC_MLCC_Microwave_Narrow_Tol_UF.pdf. We compared the two rows field by field: capacitance, size, dielectric, rated voltage, L, W and T are identical, and the Tolerance column is not — the UF row reads +-0.02pF and the RF row reads +-5%, though both carry the P code.

Can you buy a tolerance tighter than ±5% in X7R at all?

Barely. 16 of 8,480 Class II rows carry a code tighter than ±5%: eight F at ±1%, six G at ±2% and two B at ±0.1 pF. That is 0.19% of the Class II population. Two of the 16 do not survive inspection, and we say so rather than quote the headline figure alone.

Part number	Dielectric column	Code	Tolerance column	Capacitance	Size	Vdc	Match / mismatch against a genuine tight Class II part
MT18B222F500	X7R	F	+-1%	2200pF	0603	50	Match — part number, column and dielectric all agree
MT18B562F500	X7R	F	+-1%	5600pF	0603	50	Match on all three
MT18B682F500	X7R	F	+-1%	6800pF	0603	50	Match on all three
1206B224F101	X7R	F	+-1%	220nF	1206	100	Match — the largest capacitance at ±1% in Class II
2220B474G501	X7R	G	+-2%	470nF	2220	500	Match at ±2%; mismatch on grade, no AEC-Q200 series
1206B102F252	X7R	F	+-1%	1000pF	1206	2500	Match at ±1%; the highest-voltage tight Class II row
MG18N1R6B500	X7R	B	+-0.1pF	1.6pF	0603	50	Mismatch — the part number’s dielectric letter is N, NP0, not X7R
1812B225B101	X7R	B	+-0.1pF	2200nF	1812	100	Mismatch — a ±0.1 pF tolerance on a 2.2 µF part is not a usable figure

Strike those last two and 14 of 8,480 Class II rows survive as genuine tight-tolerance parts. The eight not listed above are 1206B472G160, 0402B181F500, 0603B684F160, 0805B121G500, 0402B271G500, 1206B102G202, 1812B682F302 and 1812B103G501.

At which case sizes does a tight Class II tolerance simply not exist?

Eight of the fourteen. We grouped all 8,480 Class II rows by case size and looked for any code tighter than ±5%. Six case sizes have at least one; eight have none at all, including 0201 with 505 Class II rows and 1210 with 806.

Case size	Class II rows	Rows tighter than ±5%	Tightest code available
01R5	41	0	K, ±10%
0201	505	0	J, ±5%
0306	3	0	J, ±5%
0402	985	2	F, ±1%
0603	1,466	5	B, ±0.1 pF (one row) then F, ±1%
0805	1,692	1	G, ±2%
1206	1,725	4	F, ±1%
1210	806	0	J, ±5%
1808	199	0	J, ±5%
1812	604	3	B, ±0.1 pF (one row) then F, ±1%
1825	71	0	J, ±5%
2211	25	0	J, ±5%
2220	263	1	G, ±2%
2225	95	0	J, ±5%
Total	8,480	16	—

0201 is the one to notice. It holds 505 Class II rows: 98 at ±5%, 273 at ±10%, 134 at ±20%, nothing tighter. If a Swedish design needs ±2% at 0201, Class II does not supply it here — Class I does, with 20 rows at ±0.02 pF, 18 at ±0.03 pF, 306 at ±0.05 pF and 540 at ±0.1 pF.

What are the real options if you need ±1% at 2.2 nF in an 0603?

There are seven, and only one of them is X7R. We filtered the export on the 222 capacitance code, the 0603 case size and the F tolerance code: MT18B222F500 is the only X7R row that comes back, and six NP0 rows come back alongside it. That single X7R part is one of the three ±1% X7R rows in the whole MT series.

Part number	Series	Dielectric	Class	Tolerance	Vdc	Match / mismatch vs “±1%, 2.2 nF, 0603”
MT18B222F500	MT, AEC-Q200	X7R	II	±1%	50	Match on all four fields; Class II, so capacitance moves with temperature and DC bias
MT18N222F500	MT, AEC-Q200	NP0	I	±1%	50	Match on value, size, tolerance and grade; mismatch on dielectric
HH18N222F500	HH, High Q / Low ESR	NP0	I	±1%	50	Match on value, size and tolerance; mismatch on series and no AEC-Q200
0603N222F500	General Purpose	NP0	I	±1%	50	Match on value, size and tolerance; mismatch — no AEC-Q200 grade
0603N222F201	Middle & High Voltage	NP0	I	±1%	200	Match on value, size, tolerance; mismatch on rated voltage, 200Vdc
0603B222J500	General Purpose	X7R	II	±5%	50	Mismatch — tolerance five times wider
0603B222M500	General Purpose	X7R	II	±20%	50	Mismatch — tolerance twenty times wider

We will not tell you a part is equivalent. We will show you where it differs — and here the real decision is not tolerance, it is class. Six of the seven ±1% options at this value and footprint are NP0, from WTC_MLCC_General_Purpose.pdf, WTC_MLCC_Automotive_MT.pdf and WTC_MLCC_HQ_Low_ESR_HH.pdf. If ±1% matters to your circuit and the capacitor sits in a timing or filter position, the Class I row is the one that holds the figure over temperature; the one X7R row holds ±1% at 25 °C and nothing in the export tells you what it holds at −40 °C. For the dielectric comparison itself, see NP0 versus X7R versus X5R.

Does the tolerance letter in the part number agree with the Tolerance column?

On 23,998 of 24,026 rows, yes. We mapped all thirteen codes to their expected string, normalised the column, and compared. 28 rows disagree. MT21B101M101 carries M, ±20%, and its Tolerance column reads +-5%. 1206N101F631 carries F, ±1%, and its column reads +-5%. Four RF15N rows carry P, ±0.02 pF, against a column reading +-5%.

A second, larger defect is a formatting one and it is our own previously published finding, reproduced here because any tolerance census has to account for it: 656 of the 788 MG series rows store the percentage as a signed decimal fraction — -0.1 where ±10% belongs, -0.05 for ±5%, -0.2 for ±20%. All 656 are in that one series. A spreadsheet reads -0.1 as minus ten percent, and MG18B222K101 is a perfectly ordinary 2200 pF 0603 100Vdc ±10% part whose Tolerance cell says -0.1.

Four more rows drop the minus sign entirely: SH31N223F101, SH31N223G101, SH31N223J101 and SH31N223K101, four consecutive 1206 NP0 22 nF 100Vdc parts whose Tolerance column reads +1%, +2%, +5% and +10%. Thirty-eight rows use the Unicode ± character where the rest of the file uses +-, and two carry a leading space. The tolerance letter in the part number is the field that survives all of this, which is why we read it rather than the column. More on the code set itself in tolerance, TCR and dielectric codes decoded.

What should a Sweden engineer do before specifying a tight tolerance in a Class II dielectric?

Check the class first, then the size. Three steps, and the first costs nothing. If your tolerance requirement is tighter than ±5% and your dielectric is Class II, the catalogue has 16 rows in 8,480 and eight of the fourteen Class II case sizes offer none — so the honest answer is usually a Class I part or a looser tolerance, and we will say which rather than imply a part exists.

1. Read character nine of the part number, not the Tolerance column. 656 rows in one series store the figure as a negative fraction and 28 rows disagree with their own code.
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, filter by commercial or automotive grade, and read every stated difference rather than a claimed match.
3. Check what is physically in Hong Kong on ready stock before committing a build slot — a dated snapshot as at 23 September 2026, not a live feed.

The full line is on the Walsin MLCC page.

The short version

Walsin’s MLCC export uses thirteen tolerance codes across 24,026 part numbers. Class I, 15,546 rows, uses eleven of them and owns all five absolute-picofarad grades. Class II, 8,480 rows, uses eight, and 99.6% of it is ±5%, ±10% or ±20%. Only 16 Class II rows beat ±5%, two of those contradict themselves, and eight of the fourteen Class II case sizes — including 0201 with 505 rows and 1210 with 806 — carry none at all. ±0.02 pF and ±0.03 pF exist at two case sizes only, 86 rows between them. The tolerance letter in the part number disagrees with the Tolerance column on 28 rows, and 656 rows in the MG series store a percentage as a negative decimal fraction. Qualification stays with you.

Send us the tolerance and dielectric your Swedish design actually needs, not a part number, and we will tell you whether any Walsin row holds it at your case size, which class you would have to move to, and what was physically in Hong Kong on 23 September 2026. And if your selector just offered you a ±2% X7R at 0201, ask it for the part number — we counted 505 Class II rows at that footprint and none of them is one.

---

Frequently asked questions

<!– wp:rank-math/faq-block {"questions":[{"id":"faq-question-01","title":"How many tolerance codes does Walsin use on MLCC part numbers?","content":"Thirteen: P, Q, A, B, C, D, F, G, J, K, M, V and Z. We read character nine of all 24,026 part numbers in the combined MLCC export to count them. Class I dielectrics use eleven of the thirteen, Class II use eight, and only six codes appear in both classes.","visible":true},{"id":"faq-question-02","title":"Can I get a ±1% tolerance in X7R?","content":"Rarely. We counted 8 rows at ±1% and 6 at ±2% across all 8,480 Class II rows, 0.19% of the population. MT18B222F500 at 2200 pF 0603 50Vdc is one of them. 99.6% of Class II rows carry ±5%, ±10% or ±20%. Confirm against the series datasheet before design-in.”,”visible”:true},{“id”:”faq-question-03″,”title”:”Which case sizes have no tight Class II tolerance at all?”,”content”:”Eight of fourteen: 01R5, 0201, 0306, 1210, 1808, 1825, 2211 and 2225. 0201 holds 505 Class II rows and the tightest is ±5%. 1210 holds 806 and the tightest is ±5%. The six that do offer something tighter are 0402, 0603, 0805, 1206, 1812 and 2220.”,”visible”:true},{“id”:”faq-question-04″,”title”:”What is the narrowest MLCC tolerance Walsin publishes?”,”content”:”±0.02 pF, code P, on 53 rows. ±0.03 pF, code Q, follows on 33. All 86 are Class I and all sit at 0201 or 0402 — no larger case size carries either grade. RF15N0R1P500 and UF15N0R1P500 are two real examples, both 0.1 pF.”,”visible”:true},{“id”:”faq-question-05″,”title”:”Why does the Tolerance column sometimes read −0.1?”,”content”:”Because 656 of the 788 MG series rows store the percentage as a signed decimal fraction rather than a percentage string. This is our own previously published finding. A spreadsheet will read that cell as minus ten percent. Read the tolerance letter in the part number instead.”,”visible”:true},{“id”:”faq-question-06″,”title”:”Does the export say whether a tolerance is initial or aged?”,”content”:”No. We checked the column headers and the export carries no initial-versus-aged distinction, no operating temperature and no qualification status. Walsin’s datasheets say AEC-Q200 compliant, never certified. Request the qualification report for your exact part number; Venatech makes no qualification claim of its own.”,”visible”:true}],”listStyle”:””,”titleWrapper”:”h3″,”titleCssClasses”:””,”contentCssClasses”:””,”sizeSlug”:””} –>

---