What are car clips for self-tapping screws and where are they used?
Automotive self-tapping clips are universal fasteners that allow you to securely fix trim, panels, moldings and other interior or body parts without the need to drill holes in advance. Their key advantage is the ability to install in metal or plastic up to thickness 3–5 mm using a regular screwdriver or screwdriver. Unlike traditional clips, which require pre-prepared holes, self-tapping options create threads directly during the screwing process, saving time and effort.
Where exactly are these clips used? Most often they are used for:
- 🚗 Mounts plastic thresholds and protective linings on the bottom;
- 🔧 Fixations trunk trim or hind wings;
- 💺 Installation of decorative panels in the cabin (for example, under the driver’s feet);
- 🔩 Installation of additional equipment: brackets for fire extinguishers, tool holders.
It is important to understand that self-tapping clips are not a complete replacement for welding or bolted connections in loaded units. They are designed for static loads up to 10–15 kg (depending on the model) and are not suitable for attaching elements subject to vibration or shock (for example, bumpers). But for fixing lightweight plastic parts, this is an ideal solution that combines simplicity and reliability.
Types of self-tapping clips: comparison of designs and materials
All car clips for self-tapping screws can be divided into three main types by design: with external thread, with internal thread and combined. Each of them has its own installation features and scope of application.
1. Clips with external thread (herringbone type)
The most common option, which is often called "herringbone clip". Their distinctive feature is threaded part on the outside of the rod, which, during the screwing process, cuts a thread in the hole. Suitable for working with metal up to 2–3 mm and plastic to 5 mm. Popular brands: Uxcell, Hilitchi, BoltDrop.
Benefits:
- ✅ Quick installation without preliminary drilling;
- ✅ Low price (from 5 rubles per piece);
- ✅ Possibility of repeated use (with careful twisting).
2. Clips with internal thread (for screws)
These clips are bushing with internal thread, into which a self-tapping screw or bolt is then screwed. They are often used to secure parts that need to be removed periodically (for example, removable panels). Suitable for metal thickness up to 4 mm. Examples: clips M6 or M8 from HEYCO or Panduit.
3. Combination clips (with rubber seal)
Combine a metal or plastic base with rubber gasket, which seals the hole and prevents corrosion. Relevant for installation in places where contact with moisture is possible (for example, in wheel arches). Popular models: HEYCO-TITE or Richco.
| Clip type | Material | Max. material thickness | Load, kg | Price for 10 pcs., rub. |
|---|---|---|---|---|
| External thread (herringbone) | Nylon, polypropylene | up to 3 mm (metal), 5 mm (plastic) | 5–10 | 50–120 |
| Internal thread (for screw) | Metal (galvanized), nylon | up to 4 mm | 8–15 | 150–300 |
| Combined (with seal) | Nylon + EPDM rubber | up to 3 mm | 5–8 | 200–400 |
⚠️ Attention: Clips from aluminum or non-galvanized steel not recommended for external installation - they quickly corrode. For outdoor work, choose stainless steel or nylon with a UV stabilizer.
How to choose the correct size of clip for a self-tapping screw
An error in choosing the size of the clip can lead to two problems: either the fastening will be hang out (if the rod is too thin), or when screwing the plastic part will crack (if the diameter is large). To avoid this, consider three key parameters:
- Rod diameter (designated as M4, M5, M6, etc.). For plastic panels it is usually enough
M4–M5, for metal parts -M6. - Thread length. She should be on
3–5 mm morethan the thickness of the materials being fastened. For example, to attach a threshold to metal 2 mm thick, a clip with a thread of 8–10 mm is suitable. - Head type. There are:
- 🔹 Secret (for hidden installation);
- 🔹 Semicircular (for decorative panels);
- 🔹 With press washer (to increase the clamping area).
To make your choice easier, use correspondence table:
| Material thickness, mm | Recommended diameter | Minimum thread length, mm | Application example |
|---|---|---|---|
| 1–2 | M4 | 6–8 | Door trim, plastic moldings |
| 2–3 | M5 | 8–10 | Thresholds, crankcase protection |
| 3–4 | M6 | 10–12 | Fastening the trunk, brackets |
⚠️ Attention: When working with aluminum or composite panels (for example, in sports cars), use clips with fine carving (step 0.8–1 mm) to avoid stripping the turns.
Check the thickness of the materials to be fastened with a caliper|Determine the type of head (countersunk/semicircular)|Make sure that the diameter of the clip matches the hole in the part|Select the material of the clip according to the operating conditions (humidity, UV radiation)-->
Step-by-step instructions for installing self-tapping clips
Installing self-tapping clips requires care, especially when working with plastic parts. Here step-by-step algorithmwhich will help you avoid errors:
1. Marking and preparing the hole
If you attach the clip to metal, first mark the center of the hole with a center punch so that the drill does not slip. For plastic, marking is not necessary - the self-tapping screw will form a hole on its own. The drill diameter should be 0.2–0.5 mm less clip diameter. For example, for a clip M5 use drill 4.5 mm.
2. Screwing in the clip
Place the clip in the hole and start screwing at low speeds (up to 300 rpm) if you use a screwdriver. For plastic panels, it is better to work manually with a screwdriver so as not to overtighten. The clip should fit all the way, but without deforming the head.
Before screwing in, lubricate the threads of the clip with soapy water or silicone grease - this will reduce the risk of breaking the turns in the plastic.
3. Checking the reliability of fastening
After installation, pull the part towards you - if the clip does not pop out and the part does not play, the mount is installed correctly. To check the load, you can hang a load weighing 1–2 kg for 10 minutes.
Typical installation errors:
- ❌ Drilling a hole larger diameter — the clip will dangle;
- ❌ Pulling the self-tapping screw leads to cracks in plastic;
- ❌ Use of clips without anti-corrosion coating for outdoor use.
What should I do if the clip rotates?
If the clip rotates in the hole, try:
1. Screw in a self-tapping screw of a larger diameter (for example, use M6 instead of M5).
2. Fill the hole with epoxy resin or sealant and re-screw the clip.
3. Install a clip with a rubber seal for better grip.
Top 5 brands of self-tapping clips: what to choose in 2026
The quality of the clips directly affects the durability of the fastening. Cheap Chinese analogues often break during installation or rust after a year. We tested the products five brands and compiled a rating based on price/quality ratio:
- HEYCO (Germany)
Leader in reliability. Clips from nylon PA66 with UV stabilizer and galvanized steel. Suitable for extreme conditions (from
-40°Cup to+120°C). Price: from 15 rub./piece. - UXCELL (China/Taiwan)
Budget option with decent quality. The range includes clips with rubber gaskets for tightness. Minus: plastic is fragile in cold temperatures below
-20°C. Price: from 8 rub./piece. - Hilitchi (China)
Specializing in clips for Japanese and Korean cars (Toyota, Hyundai, Kia). There are models with an enlarged head for soft plastics. Price: from 10 rub./piece.
- Panduit (USA)
Premium segment. Clips from glass filled nylon withstand vibrations and chemical influences. Used in industry. Price: from 30 rub./piece.
- BoltDrop (Russia)
Domestic brand with a good price/quality ratio. The line includes clips with anti-vandal head (difficult to unscrew without special tools). Price: from 12 rub./piece.
For most tasks in garage conditions, the optimal choice is HEYCO or BoltDrop. If you need a budget option for a one-time repair, this is suitable UXCELL.
Clips from Panduit and HEYCO have a lifetime warranty from the manufacturer subject to installation conditions.
Common problems and how to avoid them
Even with the right choice of clips, you can encounter problems if you do not take into account the nuances of materials or operating conditions. Let's consider three typical situations and ways to solve them:
1. The clip does not stay in the plastic
Cause: The plastic is too soft (e.g. polypropylene in bumpers) or the hole widened when screwing in. Solutions:
- 🔧 Use the clip with enlarged threaded part (for example,
M6×12instead ofM6×8); - 🔧 Submit metal washer under the head to distribute the load;
- 🔧Apply adhesive sealant (for example, Loctite 406) before screwing.
2. Corrosion of clips on outdoor parts
Uncoated metal clips rust in 1-2 seasons, especially in wheel arches. How to prevent:
- 🛡️ Choose clips from stainless steel A2/A4 or with zinc coating;
- 🛡️ Apply anti-corrosion lubricant (for example, WD-40 Specialist) after installation;
- 🛡️ For plastic parts use nylon clips - they do not rust.
3. Cracks in plastic during installation
Most often this happens due to:
- ⚠️ Too much large diameter clips;
- ⚠️ Self-tapping screws;
- ⚠️ Installation at temperatures below
+5°C(plastic becomes brittle).
Solution: preliminary heat the plastic with a hairdryer up to 40–50°C and use the clips with fine carving.
⚠️ Attention: When attaching parts to galvanized metal (for example, on new cars) use clips with EPDM rubber gasketto avoid electrochemical corrosion.
Alternatives to self-tapping clips: when they don't fit
Self-tapping clips are a universal solution, but not a panacea. In some cases it is better to use other types of fasteners:
| Situation | Recommended Alternative | Benefits |
|---|---|---|
| Fastening heavy parts (more than 15 kg) | Bolts with nuts + engraving washers | Withstands loads up to 50 kg, reliable fixation |
| Mounting on thin metal (less than 1 mm) | Rivets (blind or threaded) | No thread required, even load distribution |
| Attachment to fiberglass or carbon fiber | Adhesive sealant (for example, 3M VHB) | No risk of material cracking |
| Frequent removal/installation of parts | Bayonet locking clips (e.g. HEYCO-Lock) | Quick installation without tools |
If you are in doubt about your choice, ask yourself two questions:
- Which load will the fastening be tested?
- Is it necessary remove often detail?
If the load is more than 10 kg or the part is removable, self-tapping clips are not the best option.
FAQ: Answers to frequently asked questions
Is it possible to use self-tapping clips to attach the bumper?
No, self-tapping clips are not suitable for bumpers. The bumper experiences dynamic loads (vibrations, shocks), and the clips are designed only for static ones. For bumper use bolts with nuts or special clips with lock (for example, HEYCO 9000).
How to remove a broken plastic clip?
If the clip breaks off, try:
- Heat the plastic around the clip with a hairdryer (no higher than
60°C) to soften the material; - Use extractor for self-tapping screws or pliers with thin jaws;
- If the clip is recessed, drill it out with a drill diameter
2–3 mm, then screw the screw into the hole and pull it out.
As a last resort, you can melt the plastic around the clip with a soldering iron and remove the remains.
Which self-tapping clips are suitable for aluminum bodies?
For aluminum you need clips with fine carving (step 0.7–1 mm) and sharp tipso as not to break the turns. Optimal options:
- HEYCO-TITE M4 (nylon, for thin aluminum up to 2 mm);
- Panduit PLT (glass-filled nylon, for thick aluminum up to 4 mm).
Lubricate the thread before screwing in special paste for aluminum (for example, Wurth ALU-Paste).
How many clips are needed to attach a plastic threshold?
The number of clips depends on the length of the threshold:
- For a threshold up to 1 m long - 4–5 clips (step 20–25 cm);
- For a threshold of 1–1.5 m - 6–8 clips;
- For a threshold of more than 1.5 m - 8–10 clips + additional screws on the edges.
Important: distribute the clips evenly, departing from the edges at least 5 cmto avoid cracks.
Is it possible to paint screw-on clips?
Yes, but with reservations:
- 🎨 Plastic clips can be painted with acrylic paints (for example, Motip);
- 🎨 Metal clips paint only after degreasing and primers (use metal primer Kudo);
- ❌ Do not use nitro paints — they corrode plastic.
For better adhesion, treat the clips before painting abrasive sponge (400–600 grit).