Every car owner sooner or later is faced with the need to replace or initially install state registration plates (GRP). It would seem that what could be simpler than screwing a metal plate to the bumper? However, it is this stage that often becomes the cause of conflicts with traffic police inspectors and unnecessary headaches when passing a technical inspection.
The problem lies in the details, or more precisely, in the fastening elements. Incorrectly selected bolt for fixing number can lead to damage to the sign itself, corrosion of the body, or, worst of all, to an administrative fine for violating installation rules. In recent years, requirements for the appearance and method of fixing the GRZ have become stricter, and the use of non-standard frames or plugs is now interpreted as introducing changes to the design or impeding identification.
In this article, we will analyze in detail the technical nuances of choosing fasteners, review current regulatory documents and learn to distinguish permitted methods of fixation from those that are guaranteed to lead to a dialogue with a police officer. Understanding these subtleties will save you time, nerves and money.
Regulatory requirements and GOST for fasteners
The main document regulating the rules for installing state registration plates on vehicles in the Russian Federation is GOST R 50577-2018. It is this standard that determines not only the dimensions of the rooms themselves, but also the requirements for their mounting. According to the latest editions, signs must be installed in places provided for by the design of the vehicle.
The key point is to prohibit the use of any additional elements that obscure or distort the symbols printed on the sign. This means that if you use a decorative frame, it should not cover even a millimeter of the numeric or alphabetic part of the number. The bolts must provide rigid fixation, preventing spontaneous unscrewing due to vibration.
⚠️ Attention: The use of transparent plugs covering the mounting screws is now considered a violation by inspectors. If the cap has a colored border or logo that overlaps the edge of the sign, this is 100% grounds for a fine.
It is also important to consider that fasteners should not show signs of corrosion, which could stain the surface of the number, making it unreadable. The standard allows the use of bolts with heads of various shapes, provided that they securely hold the sign and do not interfere with the reading of data by cameras that automatically record violations.
Thread sizes and types: Metric
In the vast majority of cases, metric threads are used to attach license plates to cars produced for the CIS and European markets. Standard size is M6. This means that the thread diameter is 6 millimeters. Using larger diameter bolts, such as M8, will require drilling holes in the bumper or body, which is not always practical and may compromise the anti-corrosion protection.
Bolt length is a parameter that is often ignored when selecting fasteners “by eye”. A bolt that is too short will not be able to reliably fix the number, especially if there is a plastic spacer or decorative frame between the body and the sign. The optimal length varies from 12 to 20 millimeters, depending on the thickness of the “pie” that needs to be fastened.
The thread pitch also matters. For standard M6 automotive bolts, the most common pitch is 1.0mm. Using fasteners with fine or coarse pitch intended for other parts of the car will result in the bolt either not tightening or, worse, stripping the thread in the factory bumper hole.
When purchasing bolts, always buy a set of 4 pieces with a spare length. Often the holes in the bumper and in the license plate do not perfectly match in depth, and the ability to choose a bolt 2-3 mm longer will save the situation.
It is worth noting that some American or Japanese cars may have inch fasteners. In such cases, use metric bolts M6 possible, but requires caution, since the thread pitch may vary. It is better to use adapters or drill new holes to the Russian standard, if the design allows it.
Materials of manufacture and corrosion protection
The choice of material for fastening the GRZ is a matter of durability. The license plate is constantly exposed to aggressive environmental influences: rain, snow, reagents on the roads, temperature changes. Ordinary uncoated steel will rust after the first winter, and it will be almost impossible to unscrew such a bolt without damaging the number.
The most common and affordable option is galvanized steel. The zinc coating creates a barrier to oxygen and moisture, significantly extending the life of the fastener. However, even zinc can corrode over time, especially in places where the coating is mechanically damaged during screwing.
- 🛡️ Stainless steel (A2, A4): An ideal option, practically not subject to corrosion, but has a higher cost.
- ⚙️ Galvanized with yellow or white chromating: A standard solution that provides good protection during regular car washing.
- 🎨 Painted bolts: They often come complete with number frames, but the paint quickly chips, opening the way for rust.
There are also special bolts with a polymer coating, which are painted in the color of the body or the number itself. This is an aesthetic solution, but it is important to monitor the integrity of the coating. If the polymer cracks, an active oxidation process will begin underneath it, which can lead to swelling of the bolt head and difficulties during dismantling.
⚠️ Attention: Never use aluminum bolts to secure numbers. Aluminum is softer than steel and can be deformed when tightened, and due to thermal expansion, it can “stick” to the steel threads in the body, after which it will not be possible to unscrew it without drilling.
Anti-vandal and hidden fastening systems
In large cities, the problem of license plate theft remains pressing. Fraudsters may steal the GRZ to use it to commit crimes, or simply for ransom. To protect against such actions, there are special anti-vandal bolts, often called "secrets".
The principle of their operation is the non-standard shape of the cap. To tighten and, most importantly, unscrew such bolts, you need a special wrench attachment, which is included in the kit. Without this key, it is impossible to unscrew the bolt with a standard open-end or socket wrench. This creates a serious obstacle for attackers who want to quickly rent a number.
However, such systems have their own nuances. Keys are often made of soft metal and can get licked off the first time you try to unscrew a bolt that is stuck with dirt. Therefore, experienced motorists recommend having a spare set of keys or storing them separately from the car.
What to do if the key to the anti-vandal bolt is lost?
There are several methods: using gas welding to weld the nut, drilling out the center of the bolt, or using special pullers. However, the easiest way is to buy a set of “anti-vandal” heads in advance, which often have a universal profile and can unscrew most types of security locks.
An alternative to security bolts are hidden fastening systems, where the number is held on latches or magnets from inside the frame. Such systems are convenient for quickly changing license plates (for example, when traveling abroad), but their reliability when driving on bad roads raises questions. Vibration can weaken the fixation, and the number will simply be lost on the track.
Fastener selection table for different cars
To simplify the selection task, we present a summary table that will help you navigate the sizes and types of fasteners for various situations. Please remember that the data may vary depending on the year of manufacture and the specific vehicle model.
| Vehicle type | Recommended size | Material | Features |
|---|---|---|---|
| Passenger cars (RF, Europe) | M6 x 14-16 mm | Galvanized steel | Standard thread, suitable in 90% of cases |
| Motorcycles | M5 x 10-12 mm | Stainless steel | Smaller diameter due to thin mounting point |
| USA/Japan cars | M6 or 1/4"-20 | Chrome/Stainless steel | Possible hole mismatch, fitting required |
| Freight transport | M8 x 20 mm | Reinforced steel | Large contact area and reliability required |
When selecting bolt length, always consider the thickness of the decorative frame, if used. A standard plastic frame adds about 2-3 mm, and a metal frame with a silicone gasket adds up to 5 mm. If the bolt is too short, you simply won't be able to tighten it all the way and the number will hang loose.
The golden rule: the length of the threaded part of the bolt entering the body must be no less than the diameter of the bolt itself (for M6 - at least 6 mm in the body body) to ensure a reliable connection.
Instructions for correctly setting the number
The installation process is simple, but following the technology will help avoid distortions and damage to the paintwork. First you need to clean the surface of the bumper and the inside of the license plate from dirt and dust. If the holes in the license plate do not match the holes in the bumper, you cannot use force - this will lead to deformation of the metal.
It is recommended to use plastic washers or special bushings between the bolt head and the surface of the number. This will prevent scratches on the mirror surface of the grommet and ensure a tighter fit. You need to tighten the bolts evenly, diagonally, gradually increasing the force so that the number is pressed evenly over the entire plane.
☑️ Checklist before installation
After installation, be sure to check that the bolt head or frame does not overlap any elements of the number. Pay special attention to the region and country code (RUS). If the frame covers at least part of the letter “R” in the region code, the inspector has every right to issue a fine.
Frequent mistakes and consequences of incorrect installation
One of the most common mistakes is using bolts that are too long without taking into account the internal structure of the bumper. As a result, the sharp tip of the bolt may rest against the radiator, intercooler or wiring located immediately behind the bumper. This can lead to damage to expensive components or short circuits.
The other extreme is the use of “self-tapping bolts” for metal or wood. They are not designed for vehicle vibration loads and quickly loosen the hole, increasing its diameter. As a result, the number begins to rattle, and with a strong jerk it can come off along with a piece of plastic.
- 🚫 No washers: causes the faceted head of the bolt to cut into the number, damaging the protective layer.
- 🚫 Padding: may break the fastening eye on the license plate itself, after which it will no longer be possible to fix it properly.
- 🚫 Ignoring rust: If you don't clean off the rust around the hole, it will quickly spread to the new bolt and number.
⚠️ Attention: If you notice that your license plate starts to vibrate or move, please fix the problem immediately. Driving with a dangling license plate may be considered a traffic hazard, especially if the license plate blocks your headlights or turn signals.
FAQ: Frequently asked questions
Is it possible to paint the license plate bolts in the body color?
Yes, this is allowed as long as the paint does not cover the characters on the license plate itself and does not interfere with their reading. However, make sure that the paint layer is not too thick and does not chip, turning into a source of corrosion.
What is the penalty for installing a number on “adhesive tape” or magnets without bolts?
According to the traffic rules, the number must be installed in the designated place in compliance with the requirements of GOST. Fastening with tape does not provide a rigid fixation. This may result in a fine under Part 4 of Art. 12.2 of the Code of Administrative Offenses of the Russian Federation (5,000 rubles) or even deprivation of rights if the inspector considers that the number was installed in violation of the state standard.
Do I need to change bolts when buying a used car?
Preferably. Old bolts often stick or have slick edges. Replacing them with new high-quality stainless steel products will take a few minutes, but will save you from problems in the future when the number needs to be removed, for example, to sell a car or undergo maintenance.
Are frame holders with inscriptions allowed?
Frames are allowed as long as they do not obscure numbers, letters, or the region code. Inscriptions on the frame (for example, the name of the dealer) are acceptable if they do not imitate signs of emergency services and do not contain obscene language. However, frames that completely hide the mounting holes (blind frames) may raise questions among inspectors.