Worried about opening the door to strangers?
This guide shows you how to add two simple devices—a door chain and a swing bar (security guard)—so you can speak through a narrow gap and physically resist forced opening.
No pro skills needed.
At a Glance
| Item | What to know |
|---|---|
| Goal | Check ID safely + slow down forced entry |
| Setup | Use both: Door Chain (check) + Swing Bar (hold) |
| Skill/Time | Beginner / ~20–30 minutes |
| Mounting height | 130–145 cm from floor (≈ 51–57 in) |
| Door gap | Chain: 3–8 cm (≈ 1.2–3.1 in); Bar clearance: 1–2 mm (≈ 0.04–0.08 in) |
| Tools | Phillips screwdriver, drill (helpful), ruler/pencil, masking tape |
| Important | These are not a replacement for your main lock/deadbolt |
Why two devices?
| Device | Job | Strength | When to use |
|---|---|---|---|
| Door Chain | Lets you open the door slightly to talk/verify | Fast to use | When the doorbell rings |
| Swing Bar (Security Guard) | Physically braces the door against pushing | Better mechanical resistance | At night or when you feel unsure |
Using both is best: Chain first to verify → Swing bar for extra holding power.
Quick Pre-Check (2 minutes)
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Hinge side vs handle side: Install on the handle side (the side opposite the hinges).
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Obstacles: Avoid clashes with door closer, smart lock, mail slot, or rubber seals.
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Rental home? Screws (mechanical fixing) are safest. If holes are a concern, confirm with your landlord or choose positions that minimize patching later.
What you need
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Door chain + swing bar kit (screws included)
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Phillips screwdriver
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Drill with 2–3 mm bit for pilot holes (optional but makes it easier)
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Ruler/tape, pencil, masking tape
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(Nice to have) A phone level app, tiny bit of rust-free lubricant
Positioning Made Easy
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Height: 130–145 cm (≈ 51–57 in) from the floor—comfortable for adults, out of reach for small kids.
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Put the chain and bar at similar heights.
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Stand inside, close the door, and mark positions on the frame (for the fixed parts) and on the door (for the moving parts).
Step-by-Step Installation
A) Door Chain (do this first)
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Tape & mark: Hold the frame plate where you want it, place masking tape on the frame, and mark screw holes with a pencil.
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Pilot holes (optional): Drill shallow 2–3 mm pilot holes to prevent slipping/splitting.
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Screw the frame plate: Keep it level; tighten until snug (don’t overtighten).
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Mark door piece: Close the door, pull the chain so the opening will be 3–8 cm (≈ 1.2–3.1 in), and mark the door piece position.
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Screw & test: Engage the chain and try opening the door. You should get a small, safe gap for talking.
Tip: If the chain feels too short, add a small link/ring to extend by 1–2 links, or move the door piece a few millimeters outward.
B) Swing Bar (Security Guard)
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Frame bracket first: Mount the bracket on the frame at a similar height to the chain so the bar swings and sits flat.
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Pilot holes → screw down the bracket level and flush.
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Mark door catch plate: With the door closed, swing the bar to find the exact catch position on the door.
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Set tiny clearance: When you screw the catch plate, leave a 1–2 mm (≈ 0.04–0.08 in) clearance so the bar locks firmly but still moves smoothly.
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Test: When engaged, the door should only wiggle a few millimeters and not open further.
Important: The swing bar does not replace your deadbolt. Always lock your main door lock when leaving or at night.
Common Mistakes (and quick fixes)
| Problem | Likely cause | Fix |
|---|---|---|
| Chain leaves almost no gap | Door piece placed too close | Move the door piece 2–3 mm outward or add a link |
| Bar won’t catch smoothly | Catch plate misaligned | Loosen screws, micro-adjust, re-tighten |
| Screws won’t hold | Hollow/weak frame | Use longer screws + wood plugs/anchors, or add a thin backing plate |
| Rattling after install | Uneven torque/loose screws | Re-tighten all screws evenly; recheck level |
1-Minute Monthly Check
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Gently pull the door: any play? Re-tighten screws if needed.
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Look for chain stretch or bar looseness; adjust or replace worn parts.
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A tiny drop of non-staining lubricant on metal contact points keeps things smooth (wipe excess).
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Height: 130–145 cm (51–57 in) on the handle side
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Chain gap: 3–8 cm (1.2–3.1 in)
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Swing bar clearance: 1–2 mm (0.04–0.08 in)
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Order: Mark → Pilot holes → Screw → Test
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Always use your main lock/deadbolt as well
