Sash Jammer Window & Door Lock, Keyed (2-Pack)
Two screws into the frame, and the arm swings over the sash so it can’t be pushed open.
- Blocks the sashThe arm swings over the edge of the sash, so the sash has nowhere to travel. Force the latch or turn the handle from outside, and the window still doesn’t open.
- Two screws, then doneThe base plate takes two screws into the window frame, and the screws are in the pack. It’s the one lock in our window range that needs a screwdriver.
- Open it in one motionSwing the arm aside and the window opens normally. Turn the key first if you locked the arm down.
- Two in the packTwo locks at about 51 g each, screws included. That covers two hinged windows, or a pair of French doors with two left over.
Why hinged windows get missed
The handle is the whole lock.
Most window security is built for windows that slide. A clamp on the track, a wedge in the channel: both assume two panels passing each other. A casement, a crank window or a tilt-turn doesn’t work that way. It swings on hinges, and the only thing holding it shut is the mechanism inside the handle. So plenty of houses end up with a locked-down back slider and a row of hinged windows nobody ever got to.
French doors are the same shape of problem, standing up. Two leaves, usually one handle doing the work, and glass from the knee to the head. The leaf itself is solid enough. Everything depends on the one point where the leaf meets the frame, and that point is a mechanism.
A sash jammer adds a second point that has nothing to do with the handle. It’s a zinc-alloy arm screwed to the frame beside the sash, and when you swing it across it sits over the sash edge. Now the handle isn’t the only thing in the way. What it can’t do is anything about the glass, and a hinged window is mostly glass. That half of the job belongs to the alarm.
Lock the handle, then hold the sash. One is a mechanism. The other is a piece of metal in the way.
Hinged, cranked or tilt-turn. Not sliders.
This one is for windows and doors that swing on hinges. Casement, crank-out, tilt-turn, and the leaves of a French door. Those are the openings where the handle mechanism is the entire lock, and the ones the rest of our window range can’t reach, because there’s no track to clamp onto and no channel to fill.
If your windows slide sideways or lift up and down, a jammer is the wrong buy. A clamp lock is the right one. It holds a sliding or double-hung window without a screwdriver, and it costs less to put on more windows. Buy the jammer for the hinged openings and the clamp for the sliders, and nothing goes into a frame that didn’t need it.
Two screws, one window at a time
Close the window and mark
With the sash shut, hold the base plate flat on the frame right beside the sash edge, where the arm will swing across onto the sash. Mark the two screw holes with a pencil.
Screw the plate down
Drive the two supplied screws through the plate into the frame. The plate needs to sit flat and tight, so the arm pivots cleanly and stays where you put it.
Swing it across and test
Swing the arm over the sash edge, then push the sash. It shouldn’t move. Swing the arm back and open the window to check nothing catches.
Do the rest of the pack
Two locks, so start with the hinged windows that are easiest to reach from outside. Ground floor first, then anything you could get to from a low roof or a fence line.
The windows a clamp lock can’t reach
Walk the house and split the openings in two. Anything that slides or lifts takes a clamp lock and no screwdriver. Anything on hinges, casement, crank, tilt-turn or a French door leaf, takes a jammer and two screws. That second group is usually the one nobody has done, because until now there was nothing to put on it. Do those, then put an alarm on the panes, because the jammer holds the frame and the alarm covers the glass.
One jammer per window. One alarm per pane.
The jammer holds the sash shut. It does nothing about the glass beside it, and a hinged window is mostly glass. The TremShield Alarm sticks to the pane and fires 125dB the moment it’s pried or struck, so the way around the jammer stops being quiet. Count your hinged windows, then count your panes. Most houses need more alarms than jammers, which is why the 6-pack works out at $16.50 each instead of $29.99.
See the alarm
Questions, answered calmly
From the security guide
How to Burglar-Proof Your Windows (Without Bars on the Glass)
A calm, complete guide to making your windows secure but still livable: the right lock for each window type, how to vent safely for air, ...
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