Chip resistor resistance values for Italy start with a string problem: Walsin writes 10 ohm as 10Ω on 236 rows and 10.0Ω on 233 more. We parsed all 234,792 ohm rows: 84 values are spelled two or three ways, on 24,001 rows. Every one is below 100 ohm.
Venatech Limited, an authorised Walsin distributor in Hong Kong, holds the 137 chip resistor export files published by Walsin Technology (Walsin). This post is written from the Resistance column of those files, read as raw text and then as numbers. Every part number below is real. The question comes from any Italian purchasing team that matches a BOM line against a catalogue by text: if the line says 10 ohm, which rows does the match find?
How many ways does Walsin write one resistance value?
Up to three, and only below 100 ohm. We read the Resistance cell on every row. 234,792 of 234,815 rows are in ohms (the other 23 are attenuator decibel values). Those rows carry 1,192 distinct strings for 1,102 distinct numeric values, so 90 strings are surplus: 78 values are written two ways and 6 are written three ways.
| Band | Rows | Distinct strings | Distinct numeric values | Values written more than one way |
|---|---|---|---|---|
| Below 1 ohm | 12,353 | 225 | 186 | 36 values, 3,739 rows |
| 1 to 9.99 ohm | 23,214 | 141 | 114 | 24 values, 8,964 rows |
| 10 to 99.9 ohm | 32,532 | 141 | 117 | 24 values, 11,298 rows |
| 100 ohm and above | 166,693 | 685 | 685 | none (0 values, 0 rows) |
We have not seen this counted anywhere. The 84 values sit on 24,001 rows, which is 35.2 percent of the 68,099 rows below 100 ohm. At 100 ohm and above every one of 685 values has exactly one string, so 100Ω, 4750Ω and 1000000Ω never split. The largest split value is 91 ohm. The six values written three ways are 0.1, 0.2, 0.3, 1, 2 and 3 ohm.
What does a text filter on 10Ω actually return?
About half the parts. We counted every row whose value is 10 ohm. There are 469. A literal match on 10Ω returns 236 (50.3 percent) and a match on 10.0Ω returns the other 233. The same holds for each neighbour: 22 ohm is 230 rows as 22Ω and 227 as 22.0Ω; 47 ohm is 243 rows as 47Ω and 252 as 47.0Ω.
| Part number | Series | Size | Tolerance | Resistance string in the export | Match / mismatch against WF04A10R0FTL |
|---|---|---|---|---|---|
WF04A10R0FTL |
Thick Film High Power Chip Resistor | 0402 | ±1% | 10.0Ω |
reference |
WA04Y10R0FTL |
Thick Film Chip Resistor Array 0402*2, Convex Type | 0402 | ±1% | 10Ω |
Match on value, tolerance and the 10R0 code. Mismatch on the string, on TCR (≦±200 against ≦±100) and on 1/16 W against 1/5 W |
WF04A100 JTL |
Thick Film High Power Chip Resistor | 0402 | ±5% | 10Ω |
Match on series, size, TCR and 1/5 W. Mismatch on tolerance, and the string drops its decimal |
WF25H10R0BTL |
High Precision Thick Film chip resistor TC100 | 2512 | ±0.1% | 10.0Ω |
Match on the string. Mismatch on series, size (2512), tolerance and 1 W |
WA06Y1R00FTL |
Thick Film Chip Resistor Array 0603*2, Convex Type | 0603 | ±1% | 1.0Ω |
Mismatch on value (1 ohm). The code says 1R00; the cell shows one decimal |
WF25H1R00BTL |
High Precision Thick Film chip resistor TC100 | 2512 | ±0.1% | 1.00Ω |
Mismatch on value (1 ohm), and a different string again from the row above |
WF04A10R0FTL and WA04Y10R0FTL carry the same value, the same tolerance and the same code characters 10R0, and the export writes them differently. A BOM tool that compares text will treat them as two different resistances.
Which tolerance bands write the trailing zero, and which do not?
Tolerance decides most of it. We grouped the 32,532 rows between 10 and 99.9 ohm by tolerance and counted the decimal point in each cell. Every one of 5,558 rows at ±5 percent, ±10 percent, ±20 percent and the three trimmable bands writes the value with no decimal. 26,902 of 26,974 rows from ±0.1 percent to ±2 percent write at least one decimal.
| Tolerance group | Rows 10 to 99.9 ohm | Written with a decimal | Written without | Match / mismatch against a filter typed as 10Ω |
|---|---|---|---|---|
| ±5% | 4,358 | 0 | 4,358 | Match |
| ±10%, ±20% | 768 | 0 | 768 | Match |
| 0/-10%, 0/-20%, 0/-30% | 432 | 0 | 432 | Match |
| ±0.1%, ±0.25%, ±0.5% | 7,634 | 7,634 | 0 | Mismatch — every row carries a decimal |
| ±2% | 190 | 190 | 0 | Mismatch |
| ±1% | 19,150 | 19,078 | 72 | Mismatch on 99.6 percent |
A buyer who types 10Ω is therefore searching, in effect, the 5 percent catalogue. The tight-tolerance parts are invisible to that string. The 1 ohm row is the extreme: 1.0Ω on 203 rows, 1.00Ω on 155 and 1Ω on 10, so no single string finds more than 55.2 percent of the 368.
Is it the same series spelling one value two ways?
Sometimes, and the exceptions are narrow. We checked the 72 rows at ±1 percent that break the tolerance pattern. All 72 sit in three array series, 24 rows each: the 04022 Convex, the 04024 Concave and the 0603*2 Convex. These write 10Ω at ±1 percent, while the neighbouring 0402*4 Convex array and the single resistors write 10.0Ω.
The other split is in the low-ohm sense parts. Below 1 ohm the current sense series use three decimals (0.300Ω, 83 rows), while the anti-surge series writes two (0.30Ω, 30 of its 32 rows) and the metal foil and automotive power sense rows write one (0.3Ω, 16 rows). WW12XR300FTL reads 0.300Ω, WK25SR300KTL reads 0.30Ω and WW12DR300FTL reads 0.3Ω. They are three different series and the same 0.3 ohm value. For what each of those series is built for, see anti-surge chip resistors.
Does the part number tell you which spelling the row will use?
No. The code inside the part number is fixed by the value, and the cell is fixed by the file it was exported from. We opened the part numbers behind both spellings of 10 ohm. WF04A10R0FTL and WA04Y10R0FTL both contain 10R0. WF04A100 JTL carries the three-digit form 100 plus a space, and the cell reads 10Ω. The tolerance letter in the part number (F, B or J) is a better guide to the cell than the value characters are. For the structural reasons part numbers do not join on text, see why Walsin part numbers do not paste into your BOM.
What should an Italian purchasing team match on instead?
A number, not a string. Parse the cell, strip the Ω, convert to a float and compare. Our free cross-reference tool states the differences from your original part field by field instead of hiding them behind a text match, which is why a 10 ohm line does not stop at the 236 rows that spell it 10Ω. Three rules, each measured above:
- Never match the Resistance column as text below 100 ohm. 84 values split, on 24,001 rows.
- Match on tolerance as well as value. The spelling tracks tolerance, so a text filter silently restricts the tolerance you meant to leave open.
- Treat three decimals, two decimals and one decimal on 0.3 ohm as one value. The sense series disagree among themselves.
The chip resistor range sits on the chip resistor page, and the stock Hong Kong holds is on ready stock — 1,125 part numbers as at 23 September 2026, a dated snapshot and not a live feed. For how rated power maps to case size on the same files, see chip resistor power rating by case size.
The short version
We parsed all 234,792 ohm rows in Walsin’s chip resistor exports. 1,192 strings name 1,102 values, and 84 values, all below 100 ohm, are written two or three ways on 24,001 rows. A filter on 10Ω returns 236 of the 469 ten-ohm parts. At ±5 percent not one of 5,558 rows carries a decimal; from ±0.1 to ±2 percent 26,902 of 26,974 do. At 100 ohm and above, no value splits. We will not tell you a part matches on resistance because a string agrees. We will show you the string the file holds and the number behind it. Qualification stays with you; confirm against both datasheets and qualify in your own circuit.
Send us the resistance and tolerance off your BOM line and we will show every row the export holds for it, in every spelling. And a question back: when your last text match for a resistor came back short, did your team add the missing decimal, or conclude the part was not there?
Frequently asked questions
Does Walsin write every resistance value one way?
No. Of 1,102 distinct values in the chip resistor exports, 84 are written two or three ways, on 24,001 rows. All 84 are below 100 ohm. At 100 ohm and above, all 685 values have exactly one string, so the split is confined to the low end.
Why does my filter for 10 ohm return half the parts?
Because the export writes 10 ohm as 10Ω on 236 rows and 10.0Ω on 233 rows. A literal match on either returns about half of the 469 real parts. The two spellings track tolerance: 5 percent parts drop the decimal, and tight-tolerance parts keep it.
Which tolerance writes the trailing zero?
Between 10 and 99.9 ohm, all 5,558 rows at plus or minus 5, 10 and 20 percent and the trimmable bands carry no decimal. Of 26,974 rows from plus or minus 0.1 to 2 percent, 26,902 carry one. The 72 exceptions are three array series at plus or minus 1 percent.
Is 0.3 ohm also written several ways?
Yes, three. Current sense parts write 0.300Ω on 83 rows, the anti-surge series writes 0.30Ω on 30 of 32 rows and the metal foil and automotive power sense parts write 0.3Ω on 16 rows. The value is identical. The spelling follows the series, so a text match finds one family only.
Does the part number tell me the spelling?
No. WF04A10R0FTL and WA04Y10R0FTL both contain the code 10R0, and the export writes them 10.0Ω and 10Ω. The cell follows the source file, and the tolerance letter in the part number is a better guide than the value characters. Parse the number instead.
How do I compare a resistance from my BOM against these files?
Strip the ohm sign, convert the cell to a number and compare the number, then compare tolerance separately. That is how a cross reference should treat the column. Our free tool states each difference from your original part rather than relying on a text match.
Do the datasheets settle which spelling is correct?
Not from the documents we hold. We hold 28 Walsin datasheets, 451 pages, of which 2 cover chip resistors (WR and MR). We read only the export column. Both spellings denote the same value, so the practical answer is to compare the number and confirm against the datasheet for your part.