Hook Bolt vs Straight Bolt: Why a Sliding Door Needs a Different Smart Lock
Sliding doors are everywhere in Australian homes — onto the deck, the courtyard, the pool area, the side path. They're also the doors most likely to be left on whatever lock came with the frame, because a smart lock that fits a hinged door won't simply fit a slider. The reason comes down to one small mechanical part: the bolt. A hinged door pushes a straight bolt into a hole in the frame. A sliding door moves sideways past the frame, so there's no hole to push into, and a different kind of bolt is needed. This guide explains the difference, what our hook-bolt options are, and what to check before you order for a sliding door.
⭐ Key Takeaways
- A straight bolt slides into the door jamb. On a sliding door there is nothing for it to grip, so the lock needs a hook bolt, which pivots and catches.
- Our push/pull locks offer two hook-bolt options: 3585 hook (35 mm backset) and 2885 hook (28 mm backset).
- Both hook-bolt options are available on the long-handle SL-P1 and the short-handle SL-P2, so the handle is a separate choice.
- Read the code as backset then centres; the centres are 85 mm on every option.
- Measure your existing sliding lock before ordering, and check the frame has a place for the hook to catch.
- The locks are IP66-rated with waterproof seals supplied, which suits a slider facing the weather.
How a Straight Bolt and a Hook Bolt Work
On a hinged door the lock case sits in the edge of the door, and when you lock it a bolt extends straight out from the edge into a pocket in the door frame. The door can't swing open because the bolt is holding it against the frame. That's the straight bolt, and it's what almost every smart lock for a hinged door uses.
A sliding door doesn't swing — it moves along a track and past the frame. If you extended a straight bolt from the edge of a sliding panel, it would simply poke into the air or the side of the frame, because the movement it needs to resist is sideways. A hook bolt solves this by pivoting: when the lock is thrown, a curved hook swings out and catches behind a keeper on the frame, so the panel can't be slid back. That's why sliding door locks look different from the inside, and why a lock designed for a hinged door can't simply be adapted.
| Question | Straight bolt | Hook bolt |
|---|---|---|
| How it locks | Extends straight into the door jamb | Pivots out and catches on the frame |
| Door type | Hinged doors | Sliding doors on a track |
| Our options | 6085, 4585, 3585, 2885 | 3585 hook, 2885 hook |
| Backset | 60, 45, 35 or 28mm | 35 or 28mm |
| Centres | 85mm | 85mm |
💡 Did You Know?
Two of the six options on each of our push/pull locks are hook-bolt versions — 2885 hook and 3585 hook — and the other four are straight-bolt. If you order a straight-bolt option for a sliding door, it will have nothing to engage on the frame, so check the option name says "hook bolt" before you add to cart.
The Two Hook-Bolt Options Explained
The code on each option reads as backset then centres. The backset is the distance from the door edge to the centre of the handle hole; the centres are the distance between the two fixing points on the lock, and on every option in this range they're 85 mm. The two hook-bolt options are:
- 3585 hook — a 35 mm backset with 85 mm centres.
- 2885 hook — a 28 mm backset with 85 mm centres.
Both are narrow because sliding door stiles are narrow. A sliding panel is typically framed in slim aluminium, and the lock has to fit inside that profile, which is why the narrow backsets exist. Which of the two you need depends on the mortise already in your door, and the quickest way to find out is to measure it. Our guide to narrow aluminium stile doors shows how to take the stile and centres measurements, and the sizing guide covers the rest.
✓ Hook-bolt options, IP66
Smart Door Lock Silver — Push/Pull Handle
Short-handle lock in brushed silver for sliding doors and narrow aluminium stiles, with 3585 and 2885 hook-bolt options.
$494.99 AUD
View Product →What to Check on Your Sliding Door Before You Order
1. The existing lock. Look at the edge of the sliding panel where the existing lock sits. If there is a mortise lock with a hook or a latch, note its shape and take a photo; the mortise pocket size is what the code refers to. If the panel has only a surface-mounted latch and no pocket, a mortise lock won't simply drop in, and it's worth talking to us before you buy.
2. The keeper on the frame. A hook bolt needs something to catch on. Most sliding doors that already have a hook lock have a keeper fitted to the frame or the adjoining panel. We can't tell from a photograph whether an existing keeper will suit a new hook, so check that it lines up with where the hook swings out once the lock is fitted.
3. The stile width. Measure the width of the aluminium stile at the lock position. If the stile is slim, the short handle is usually the sensible choice, as explained in our guide to long versus short handles.
4. The weather exposure. A slider facing a deck, a courtyard or the pool is usually fully exposed to rain, spray and sun. The push/pull range is IP66-rated with a published range of −25°C to 70°C and waterproof seals supplied; our explanation of what IP66 means covers what that does and doesn't promise.
| Check | What to look for | If it doesn't match |
|---|---|---|
| Existing lock type | A mortise lock case in the panel edge | Send us a photo before ordering |
| Backset | 35mm (3585 hook) or 28mm (2885 hook) | Re-measure from the edge to the centre of the handle hole |
| Centres | 85mm between fixings | Check the sizing guide or contact us |
| Frame keeper | Something for the hook to catch on | A keeper may need fitting or adjusting |
| Stile width | Narrow stile points to the short handle | Compare the dimension drawings |
✓ Sliding door, matte black
Smart Door Lock Black — Push/Pull Handle
The same short-handle lock in matte black for sliding doors and framed glass, in six mortise options including two hook bolts.
$494.99 AUD
View Product →Using the Lock Day to Day
On many sliding doors the handle is also what you grip to slide the panel. The lock reads your fingerprint, code, IC card, phone or remote control, releases the hook and lets you slide the door. When you close the door and lock it, the hook swings out and catches. As with every lock in this range, two mechanical keys are supplied, so if the four AA batteries ever run flat you can still get in; our guide to what happens when the batteries die explains the steps.
It's worth being realistic about what a single lock does for a sliding door. A hook bolt keeps the panel from being slid open from the lock side, but a sliding door's overall security also depends on the frame, the track, the glass and any anti-lift features. We'll cover insurers' expectations in a later guide; for now, treat the smart lock as a convenience and access-control upgrade rather than a replacement for a well-set-up door.
Shop the Sliding Door Range
Push/Pull & Sliding Door Smart Locks
IP66 bar-handle locks with waterproof seals supplied — long and short handle, silver and black, with 3585 and 2885 hook-bolt options for sliding doors.
Shop the Collection →For how the push/pull design compares with a lever, see push/pull versus turn-handle smart locks, and for every model side by side, the complete buying guide.
Frequently Asked Questions
What is a hook bolt on a smart lock?
A hook bolt is a curved bolt that pivots out from the lock and catches on a keeper on the frame. It is used on sliding doors, where a straight bolt has nothing to slide into.
Can I use a straight-bolt lock on a sliding door?
No. A straight bolt extends into the door jamb, and a sliding door moves past the frame instead of closing against it, so the bolt would have nothing to engage. Choose a hook-bolt option.
Which hook-bolt options do you offer?
Two: 3585 hook, with a 35 mm backset, and 2885 hook, with a 28 mm backset. Both have 85 mm centres and are available on the long and short handle versions.
How do I know whether I need 3585 or 2885?
Measure the mortise in your existing sliding door: the distance from the panel edge to the centre of the handle hole is the backset. Match it to 35 mm or 28 mm.
Will the lock work in the rain?
The push/pull range is IP66-rated with waterproof seals supplied and a published operating range of −25°C to 70°C, so it is suited to a slider that faces the weather.
Can I send a photo before I order?
Yes. A photo of the lock edge of the door with a tape measure across it is the quickest way for us to confirm the right option.
Key Takeaways
- A sliding door needs a hook bolt; a straight bolt has nothing to grip. Choose 3585 hook or 2885 hook.
- Both hook-bolt options come on the long-handle SL-P1 and short-handle SL-P2; pick the handle using long vs short handle.
- Measure the existing mortise and check the frame keeper; see narrow aluminium stile doors and the sizing guide.
- Exposed sliders suit the IP66 rating — read IP66 explained.
- Browse the push/pull range or compare models in the complete buying guide.