In short. A wheel marking is read in two parts. The size line, such as 8.5Jx19 H2 ET45 5x112 66.6, says: 8.5 inches between the flanges; a J-shaped flange; "x" for a one-piece wheel; 19 inches across the bead seats; H2, a safety hump on both bead seats; ET45, an offset of +45 mm; five bolt holes on a 112 mm circle; and a 66.6 mm centre bore. Around it are stamps: the maker, the date (at least the month and year), a part number, sometimes a maximum load in kilograms, and the mark of a standard or an approval. JWL is a Japanese standard that the maker applies to itself; VIA means a third party in Japan has run the tests on the design and registered it, and it often comes with a load such as "VIA690KG"; an E in a circle followed by "124R" is a UN approval; KBA and a number is a German national permit. Check the load against your car's plate: the wheel should carry at least half the heaviest axle load printed on it. No stamp says that a wheel fits your car: that comes from the car's list and the measurements.
Where the markings are
Look on the back of the spokes, on the inner face of the barrel (the part the tyre covers on the inside), and around the hub face. UN Regulation No. 124 asks for the markings to be permanent, legible and visible with the tyre fitted, at a place the maker chooses (Regulation No. 124, § 5.1). The Japanese standard asks for its mark to be easy to check with the wheel on the car, and for the marks to be cast in or stamped (MLIT, Annex 2, § 4.1). A German permit we read puts the approval number on the outer face and the rest on the inner face (KBA, permit 48207, § IV.2). So take the wheel off, clean the back, and use a torch at a low angle: cast lettering shows best in raking light. To take a wheel off, raise the car and rest it on axle stands, never on the jack alone, and refit the nuts to the torque the car maker gives (see how to change a wheel safely and wheel nut torque).
The size line, element by element
| Part | In 8.5Jx19 H2 ET45 5x112 66.6 | What it means | Where it is defined |
|---|---|---|---|
| Width | 8.5 | Rim width in inches, measured between the flanges, the lips that hold the tyre (216 mm) | ISO 3911 designation, cited by Regulation No. 124 (§ 2.2.2) |
| Flange contour | J | The shape of the flange. J is the usual contour on car wheels; B is another (a German wheel maker's glossary) | Same |
| Construction | x | "x" for a one-piece wheel, "-" for a multi-piece one | Regulation No. 124, § 5.1.2.1 |
| Diameter | 19 | Nominal diameter in inches, measured across the bead seats where the tyre sits, not across the outside of the lips | Same |
| Hump | H2 | A ridge on the bead seat that helps hold the tyre on its seat; "2" means on both seats (the German permit we read writes "Doppelhump", double hump). FH is a flat hump; the regulation's own example marks FH on one side only and calls this marking optional | Regulation No. 124, Annex 3 |
| Well position | (absent) | An optional "A" (asymmetric) or "S" (symmetric) for where the well sits | Regulation No. 124, § 5.1.2.1 |
| Offset | ET45 | +45 mm from the mounting face to the rim's centre line; also written "INSET 45" or "+45" on wheels made to the Japanese standard | See wheel offset |
| Bolt pattern | 5x112 | Five holes on a 112 mm circle; German documents write it "LK 112" | See PCD and centre bore |
| Centre bore | 66.6 | The diameter of the centre hole in millimetres, sometimes written "CB66.6" or "Ø66.6" | Same |
Three points that the pages ranking for this question tend to skip:
- The order can be reversed. Regulation No. 124 allows "5½ J x 14 FH" to be written "14 x 5½ J FH" (Annex 3). North American wheels are usually written diameter first, so "19x8.5" is the same rim as "8.5Jx19".
- A wheel never has to carry all of it in one place. The offset, the date and the maker's name "may be at a distance from the rim designation" (Annex 3), and the bolt pattern and centre bore are not among the markings Regulation No. 124 requires at all (§ 5.1). On many wheels you will find the size on one spoke, the offset on another, and nothing about the bore.
- "Japanese" wheels speak of inset. The Japanese standard uses "inset" (+), "zero set" (0) and "outset" (−) for what Europe calls ET (MLIT, § 2.1.1). An "outset 10" is ET−10.
To compare the offset and width of two wheels, use the wheel offset calculator; to measure a wheel with no marking, see what size wheels fit my car.
The stamps, and which text asks for each
| Stamp | Looks like | What it says | Who asks for it |
|---|---|---|---|
| Maker | A name, a logo or initials | Who made or sells the wheel | Regulation No. 124 § 5.1.1; JWL § 4.1; German permits |
| Date | "01 99", "09/24", "2409", or a symbol | Month and year of manufacture, at least | Regulation No. 124 § 5.1.4 (example: "0199" is January 1999); German permits (month and year) |
| Part number | Letters and digits, such as "ab123" | The maker's reference for that exact wheel | Regulation No. 124 § 5.1.5 |
| Version or design code | "BX655 5 35" in the German permit we read | Model, number of holes and offset in one code | German permits |
| Foundry or cavity mark | Letters and a number, such as "HL 3" | Which foundry or mould produced the casting | German permit 48207 (§ IV.2), wheel makers |
| Maximum load | "MAX LOAD 690 KG", "1521 LBS" | The highest load per wheel it is rated for | Wheel makers; German permits list it per version |
| VIA load | "VIA690KG" | The load the wheel was registered for in Japan | NAPAC (VIA) |
| JWL / JWL-T | The letters JWL in a frame | The maker declares the design meets the Japanese standard (JWL-T: trucks and buses) | MLIT standard § 4.1 |
| VIA | The letters VIA in a frame | A third party in Japan has run the tests on the design and it is registered | NAPAC (VIA) |
| UN approval | E in a circle with a number, then "124R-00…" | A replacement wheel type granted approval under Regulation No. 124 | Regulation No. 124 § 4.4 |
| KBA | "KBA 48207" | A German national permit for an aftermarket wheel | German permits |
| DOT | "DOT" on the rim | The rim maker's statement that the rim complies with US federal standards, required on rims for heavy vehicles and motorcycles | FMVSS No. 120 S5.2 |
| Repair marks | A refurbisher's name; a repairer number and a severity digit | The wheel has been refurbished or repaired | German guideline (2022); B.C. Reg. 5/97 |
The rest of this guide takes them one by one.
JWL: a standard the maker applies to itself
JWL stands for Japan Light Alloy Wheel. It is the technical standard of Japan's transport ministry for light-alloy wheels on passenger cars (not on vehicles with eleven seats or more, nor on two-wheelers). The maker runs the tests on its own responsibility and then marks the wheel; the ministry judges conformity by the presence of that mark (NAPAC). In Japan, a light-alloy wheel that carries the mark and is not damaged is deemed strong enough under article 89 of the safety rules (MLIT, article 89). Outside Japan the mark has no legal force of its own.
The standard has three tests, and the formulas are worth reading because they show what the mark is about (MLIT, Annex 2, § 2 and 3):
| Test | What is done | Values in the text | Pass |
|---|---|---|---|
| Rotary bending fatigue | The rim is clamped to a turntable and a shaft bolted on like a hub applies a constant bending moment | M = 1.5 × F × (0.7 × r + d); at least 100,000 turns, or 50,000 if the factor is raised to 1.8 (certain wrought aluminium-magnesium sheet alloys) or 2.0 (cast and forged aluminium alloys) | No crack under dye-penetrant inspection, no notable deformation, no abnormal loosening of the nuts |
| Radial fatigue | The wheel and its tyre are pressed against a rotating drum | Q = 2.25 × F (2.5 may be used for a front wheel); at least 500,000 turns; tyre at no less than its maximum pressure | Same |
| 13° impact | The wheel and tyre are tilted at 13° and a weight is dropped on the rim flange | Mass of 0.6 × W + 180 kg, dropped from 230 mm; tyre at 200 kPa | No crack through the wheel, no separation of rim and disc, no rapid air loss |
F is the highest load capacity, in kN, of the tyres the wheel is made for; W the same in kg; r the largest static loaded radius of those tyres, in metres; d the offset, in metres.
What that means in numbers. Take a wheel whose most heavily rated tyre carries 615 kg (load index 91, 6.03 kN), with an offset of +45 mm, and assume a static loaded radius of 0.30 m (our assumption, for the example only). The bending test applies 1.5 × 6.03 × (0.21 + 0.045) = 2.31 kN·m; the radial test presses with 2.25 × 6.03 = 13.6 kN, about 1,380 kg; the impact test drops 549 kg from 230 mm. Two things follow. The test load comes from the tyre's load capacity, not from one car. And the offset is inside the bending formula, so the same design at a different offset is a different test case.
VIA: the third-party test, and the load figure beside it
Because JWL is self-declared, wheels for the aftermarket in Japan go through a confirmation test. The automotive light-alloy wheel testing council has the tests carried out by the Japan Vehicle Inspection Association, a public third-party body; a design that passes is registered with the council and carries the VIA mark (NAPAC). Members of the Japanese wheel makers' association may add a JAWA sticker to registered products, which comes with product liability insurance.
The load beside the VIA mark has a precise meaning. For wheels limited to a given hub fitting, the council marks the highest static wheel reaction of the vehicles in that fitting as a load symbol, such as "VIA690KG", and the wheel reaction is defined as half the axle load at gross vehicle weight. A wheel marked for both cars and trucks carries "VIA-P" or "VIA-T" before the load (NAPAC, sizes and markings).
So a JWL stamp alone is the maker's own declaration; JWL with VIA is that declaration confirmed by a tester. Neither mark tells you that the wheel fits your car.
The UN approval mark: E, a number and 124R
Regulation No. 124 is the UN rule for approving replacement wheels for passenger cars and their light trailers. It does not cover original-equipment wheels, the car maker's own replacement wheels, or "special wheels", which stay under national approval (§ 1). So the original wheels on your car will usually not carry it.
A wheel with this approval carries a circle with the letter E and the number of the country that granted the approval (1 is Germany, 2 France, 3 Italy, 11 the United Kingdom), then "124R", a dash and the approval number. The regulation's own example is a wheel whose approval was granted in Italy (E3) under number 001148; the first two digits of the number give the series of amendments in force at approval, 00 for the original text (§ 4.4 and Annex 2). The number in the circle is the approving authority, not where the wheel was made.
KBA: the German permit
A German aftermarket wheel sold with a general operating permit (Allgemeine Betriebserlaubnis) carries a type mark allotted by the Federal Motor Transport Authority. In the permit we read, the authority writes that the wheel "receives the type mark KBA 48207" and that this mark must be applied, permanently and legibly from outside, to every wheel produced. The test report attached to it lists, for each version, the bolt pattern, the offset, the centre bore, the permitted rolling circumference and the permitted wheel load (620 kg for that 6½J x 15 wheel), and the cars the wheel may be fitted to. It also requires centring rings to be marked with their inner and outer diameters (KBA permit 48207, 5 November 2010).
The KBA number is the key to the document, not a verdict in itself: the permit says which cars and which versions it covers, and outside that list it does not apply.
DOT and the American rules
In the United States, the federal rule on rim marking, FMVSS No. 120, applies to vehicles with a gross vehicle weight rating over 4,536 kg (10,000 lb), to motorcycles and to rims for those vehicles. For them it requires a source designation for the rim's dimensions (such as "T" for The Tire and Rim Association or "J" for the Japanese tyre makers' association), the size, the symbol DOT as the rim maker's statement that the rim complies with all applicable federal standards, the maker's identity, and the date: month, day and year or month and year, in figures or by a symbol at the maker's option (49 CFR 571.120, S3 and S5.2). That last option is why some date codes are dots or dials rather than digits. An industry standard, SAE J2530, covers aftermarket wheels for North America; its text is paid and we have not read it.
The load: how to check it against your car
A maximum load stamped on a wheel is per wheel. To compare it with the car, use the manufacturer's statutory plate, usually on a door pillar or under the bonnet: it shows "the technically permissible maximum mass on each axle", front to rear (Regulation (EU) No 19/2011, Annex I, § 2.1, in the version published on legislation.gov.uk; in the EU the plate rule has since moved to Implementing Regulation (EU) 2021/535). In the United States, the axle ratings (GAWR) are on the label the vehicle maker fixes by the driver's door (49 CFR 567.4). The arithmetic is the one the Japanese council uses for VIA:
| Step | Example |
|---|---|
| Read the highest axle mass on the plate | 1,330 kg on the rear axle |
| Divide by two | 665 kg per wheel |
| Compare with the load marked on the wheel | A wheel marked 690 kg covers it; one marked 620 kg does not |
The figures in the example are illustrations, not values for a car. If the wheel shows no load at all, ask its seller for the rated load in writing; a German permit, if there is one, gives it per version. The tyre has its own load index, which must also be at least what the car's maker lists: see how to read a tyre size. The full method, with a worked example on a real car, is in how to choose aftermarket wheels.
Repair and refurbishment marks
A wheel can carry marks added after it left its maker. In British Columbia, a repair facility stamps each weld-repaired wheel, next to the valve hole, with the vendor number the province assigned to it, the date and a severity rating from 0 (minor cosmetic) to 9 (straightening combined with welding), and a wheel judged unsafe is stamped "UNSAFE" (B.C. Reg. 5/97). Germany's 2022 guideline asks a refurbisher to mark the inside of the wheel with at least a name and address, by a method that does not cut into the metal, and to keep the maker's markings intact (KÜS note). A wheel with a stamp you cannot place may have been repaired: our guide to alloy wheel repair sets out what the texts allow.
What the markings cannot tell you
- Whether the wheel fits your car. That depends on the bolt pattern, the bore, the diameter, the width and the offset your car lists, plus brake and arch clearance. The wheel size guide covers the method.
- Whether a stamp is genuine. A cast or stamped mark can be copied. A VIA registration or a KBA permit is checked through its documents, not through the lettering.
- What has happened to the wheel since. A crack, a buckle or a repair is found by inspection and measurement, not by reading.
At the MOT in Great Britain, the tester looks at the wheel as fitted. The manual lists, among others, a wheel and fixings that are not compatible as a major defect and any fracture or welding defect on a wheel as dangerous (MOT inspection manual, 5.2); see our MOT guide.
A full reading, start to finish
Here is a made-up back of a wheel, of the kind you will find, read line by line.
| Marking found | Reading |
|---|---|
| ABCDE | Maker's name or trademark |
| 8.5Jx19 H2 | 8.5-inch rim, J flange, one-piece, 19-inch, humps on both bead seats |
| ET45 | Offset +45 mm |
| 5x112 · CB 66.6 | Five holes on 112 mm; 66.6 mm centre bore |
| MAX LOAD 690 KG | Rated for 690 kg per wheel |
| JWL · VIA690KG | Maker declares the Japanese standard; third-party registration in Japan at 690 kg |
| 03 24 | Date of manufacture: March 2024 |
| AB-8519-45 | Part number |
That reading tells you what the wheel is. Whether it suits a given car is a separate check, made against the car's list and its plate.
Common mistakes
- Reading the outside of the lips as the width. The nominal width is between the flanges; across the outside of the lips a wheel measures about an inch more.
- Taking the E-mark number for the place of manufacture. It is the country whose authority granted the approval.
- Taking a JWL stamp for a third-party test. JWL is the maker's own declaration; VIA is the third-party step.
- Ignoring the load because the size is right. Two wheels with the same size line can be rated for different loads.
- Assuming no bore marking means a hub-centric fit. The bore is often not marked at all: measure it.
If the wheel is one of ours
Onyx Forged wheels are made to order from the measurements of your car, and are designed to JWL/VIA standards: they are drawn to the criteria of those tests (fatigue, impact), at your car's dimensions. That phrase describes how a wheel is designed; it is not a claim that a given wheel carries a VIA registration or an approval mark. Onyx Forged does not recommend a size or an offset: the bolt pattern, bore, diameter, width and offset come from your car maker's documents, which we compare against. For what forging changes compared with casting, read forged, cast and flow-formed wheels. See Onyx Forged and the catalogue.
Frequently asked questions
What does 8.5Jx19 ET45 mean on a wheel?
A rim 8.5 inches wide between the flanges, with a J flange, one-piece (x), 19 inches across the bead seats, and an offset of +45 mm from the mounting face to the rim's centre line.
What does H2 mean on a wheel?
A safety hump on both bead seats, a ridge that helps hold the tyre on its seat. FH is a flat hump; the UN regulation treats the hump marking as optional.
What does JWL mean on a wheel?
Japan Light Alloy Wheel: the Japanese transport ministry's standard, with three tests (bending fatigue, radial fatigue, 13° impact). The maker runs them on its own responsibility and marks the wheel.
What is the difference between JWL and VIA?
JWL is the maker's own declaration. VIA means a third-party body in Japan has carried out a confirmation test and the design is registered with the testing council.
What does VIA690KG mean?
The wheel is registered for a load of 690 kg, defined as the highest static wheel reaction of the vehicles it is meant for: half the axle load at gross vehicle weight.
How do I find the load rating of a wheel?
Look for "MAX LOAD", "LOAD" or a VIA load in kg or lb on the back. Compare it with half the heaviest axle mass on your car's plate. If none is marked, ask the seller in writing.
How do I find out when a wheel was made?
Regulation No. 124 requires at least the month and year; its own example "0199" means January 1999. Some makers use a dial or dots instead of digits, which their documents decode.
What does an E-mark with 124R mean on a wheel?
A replacement wheel type granted approval under UN Regulation No. 124. The number in the circle is the approving country (E11 for the United Kingdom); the digits after "124R-" are the approval number.
Where is the centre bore marked?
Often nowhere. When it is, it appears as a plain number (66.6), "CB" or "Ø" with the diameter in millimetres. Otherwise measure it with calipers.
Where to go next
For the names of the parts (flange, bead seat, hump, barrel), see parts of a wheel. For the measurements behind the size line, read wheel offset, PCD, bolt pattern and centre bore and what size wheels fit my car. For the tyre's side of the same check, how to read a tyre size. If your wheels have a bright machined face, diamond cut alloy wheels explains how to keep it. Onyx Forged is a French brand of made-to-order forged wheels, designed to JWL/VIA standards: see Onyx Forged and the catalogue.
Sources
- UN Regulation No. 124, wheels for passenger cars and their trailers (Official Journal L 375 of 27 December 2006): § 1, 2.2, 4.4, 5.1, Annexes 2 and 3.
- Japan's Ministry of Land, Infrastructure, Transport and Tourism, technical standard for light-alloy disc wheels (version of 7 July 2008), § 2 to 4.1, and article 89 (version of 10 January 2025), in Japanese.
- NAPAC, JAWA division, quality criteria for aluminium wheels and wheel size and other markings, in Japanese.
- Kraftfahrt-Bundesamt, general operating permit no. 48207 and its test report (5 November 2010), in German.
- 49 CFR 571.120, FMVSS No. 120, S3 and S5.2.
- 49 CFR 567.4: the US vehicle label and axle ratings.
- Commission Regulation (EU) No 19/2011, Annex I, § 2.1: the manufacturer's statutory plate.
- GOV.UK, MOT inspection manual, section 5.2.
- B.C. Reg. 5/97, weld repair of aluminium alloy wheels; KÜS note 2303001, German guideline of 5 December 2022 on refurbishing light-alloy wheels, in German.
- A German wheel maker's page, composition of a wheel rim (14 February 2020).
All pages were read on 15 October 2026; the Japanese and German texts are cited as read, in our translation.
The Onyx Forged design office.