If you’re fabricating a new metal gate for the Aqara Smart Gate Lock U500, the most common question is simple: how much flat surface does the gate need so the lock seats properly? Leave too little flat area — or make the surface uneven — and the inner and outer panels won’t sit flush, so installation gets difficult. This guide gives your metalworker the exact plate size and gate specs before they start welding.
The Aqara Smart Gate Lock U500 is a purpose-built retrofit for outdoor metal and iron gates, with fingerprint and key access on both sides of the gate.
Quick answer: the recommended flat plate size
For a custom gate, provision a flat solid plate of at least 100 mm wide × 250 mm high (100 mm W × 250 mm H) at the lock position, and make sure the surface is flat and even. This is the plate size recommended by the Aqara distributor, based on their standard Smart Gate Lock U500 demo stand — it comfortably fits both the inner and outer panels.
Hand this to your gate maker: a flat, even plate 100 mm (W) × 250 mm (H), gate/plate thickness 22–28 mm, with the frame flush to the gate face.
The Aqara Smart Gate Lock U500 panel dimensions
| Panel | Height | Width | Depth (off the gate) |
|---|---|---|---|
| Outer panel (fingerprint / keypad side) | 148.7 mm | 71.7 mm | 27.3 mm |
| Inner panel (rear side) | 167.5 mm | 72.9 mm | 49 mm |
The widest panel is about 73 mm, so a 100 mm-wide plate leaves sensible clearance each side. The tallest panel is about 167.5 mm — but you should not size the plate to the panel height alone. Here’s why.
Why the plate height needs to be bigger (≈250 mm)
On the Aqara Smart Gate Lock U500, the inner and outer panels are not positioned at exactly the same height on the gate. Because the two sides are offset, the combined flat area they cover is taller than either single panel — which is why the recommended plate height (250 mm) is noticeably larger than the tallest panel (167.5 mm). The extra height guarantees both panels land fully on flat metal, with room to spare.
Why the surface must be flat and even
The Gate Lock U500 clamps against a flat, even face. If the mounting area is curved, ribbed, or has raised welds or grille bars in the way, the panel can rock or leave gaps — affecting both the weather seal and the security of the fixing. Specify a solid flat plate at the lock position rather than mounting across the gaps between grille bars.
Gate thickness and drilling requirements
Beyond the flat plate, make sure the gate falls within the Gate Lock U500’s supported ranges:
| Suitable for | Iron / metal gates (HDB metal grille gates included) |
| Gate / plate thickness | 22–28 mm |
| Hole diameter | ø12 mm × 2, plus ø50 mm × 1 |
| Backset | 40–45 mm |
| Door gap | 3–7 mm |
| Frame | Interior frame must be flush with the gate |
Doors with different dimensions may require modification. For a standard HDB metal gate, the Gate Lock U500 fits without much issue — the key is getting the flat plate and thickness right at fabrication.
Glass gates: drill the holes before installation day
If your gate has a glass panel near the lock area, your gate fabricator must drill the mounting holes in advance — before the lock is installed. The Aqara-appointed locksmith will not open new holes on a gate with glass, because drilling near a glass panel risks the glass shattering. They will fit the Aqara Smart Gate Lock U500 into holes that already exist, but they won’t create them on a glass gate.
Give your gate maker the drilling template below so the holes are opened in the correct positions and sizes ahead of time:
- Two × ø12 mm through-holes, spaced 68 mm apart.
- One × ø50 mm through-hole (the main body cut-out).
- Backset 40–45 mm from the edge of the gate.
- Confirm door handing first (hinge on right = RH, hinge on left = LH) and follow the template’s orientation.
Checklist to give your gate contractor
- Flat, solid plate at the lock position: 100 mm (W) × 250 mm (H) minimum.
- Surface flat and even — no ribs, curves or raised welds under the lock.
- Gate/plate thickness 22–28 mm.
- Allow for drilling: 2 × ø12 mm holes and 1 × ø50 mm hole.
- Backset 40–45 mm, door gap 3–7 mm, frame flush with the gate.
- Confirm the plate position works for both panel heights (they’re offset).
Planning a new gate?
If you’re building a new gate and want to be sure the Aqara Smart Gate Lock U500 fits perfectly, share this page and the checklist with your metalwork contractor before fabrication. Getting the flat plate and thickness right from the start saves costly rework.
Questions about fitment or installation? WhatsApp our team (+65 9051 7063), or browse the full Aqara smart lock range.
Frequently asked questions
What size flat plate does the Aqara Smart Gate Lock U500 need on a custom gate?
Provision a flat, even plate of at least 100 mm wide by 250 mm high at the lock position — the size of the distributor’s standard demo stand.
Why is the recommended plate taller than the lock panel?
The inner and outer panels of the Gate Lock U500 mount at slightly different heights, so the flat area they cover together is taller than either panel alone. A 250 mm plate height ensures both sides land fully on flat metal.
What gate thickness does the Aqara Smart Gate Lock U500 support?
It is rated for a gate or plate thickness of 22 to 28 mm, with a backset of 40 to 45 mm and a door gap of 3 to 7 mm.
Does the Aqara Smart Gate Lock U500 work on HDB metal gates?
Yes. For a standard HDB metal grille gate it fits without much issue, provided the lock area is a flat, even plate within the supported thickness range.