how to choose? 3 shield expansion bolt and 4 shield expansion bolt
| Choose 3pcs expansion bolts for concrete | Choose 4pcs expansion bolts for concrete | |
|---|---|---|
| The hanging objects are light (<20kg) | ✅ Hanging pictures, small shelves | ❌ Not necessary |
| The hanging objects are heavy (>50kg) | ❌ May not hold up | ✅ Air conditioners, machines, shelves |
| Solid wall (concrete) | ✅ Can be used for light work | ✅ More stable for heavy work |
| Soft wall (brick wall) | ❌ Easy to pull out | ✅ Must have four pieces |
| Will vibrate (washing machine) | ❌ Will loosen over time | ✅ Anti-shake and anti-fall |
| Outdoor/humid | ❌ Ordinary three pieces will rust | ✅ Stainless steel four pieces, durable and not rotten |
1. According to “how heavy the hanging objects are”
Three pieces: suitable for things under 20 kg, such as:
Home hanging pictures, wall lamps, small shelves
Lightweight ceiling, PVC water pipe fixing
Four pieces: suitable for more than 50 kg Heavy objects, such as:
Air conditioner outdoor unit, water heater, anti-theft net
Machines in the factory, heavy shelves
⚠️ Note: If it is a tile wall or hollow brick wall, even if the object is not heavy, it is recommended to use four pieces, because the wall itself is not strenuous, and more expansion pieces are more stable!
2. According to “whether it will vibrate frequently”
Three pieces: suitable for things that do not move much, such as:
Bookcases, TV cabinets (basically do not move after installation)
Fixed decorative racks
Four pieces: suitable for things that vibrate and shake, such as:
Washing machines, generators (buzzing when working)
Factory machine tools, ventilation ducts (long-term vibration)
Experience: Use four pieces in places where the machine vibrates a lot, otherwise the screws will easily loosen and may fall off after a long time!
3. Look at the “wall material”
Concrete wall (the strongest): three pieces and four pieces can be used, and it is safer to choose four pieces for heavy objects.
Brick wall/hollow brick (easy to crack): four pieces are preferred, with stronger grip to avoid loosening.
Tile/marble (afraid of cracking): four pieces must be used, and be careful when drilling holes, otherwise the tiles will break!
4. Check “whether the environment is humid or not”
Dry environment (home, office): three pieces are enough.
Wet/outdoor (bathroom, factory, billboard):
Choose four pieces + stainless steel material