Key takeaways
- A strike has to match both the lock and the frame prep. Two plates of the same outside size can have different openings.
- The most common strike cutout in a steel frame is 4-7/8 inches tall, followed by 2-3/4 and 3-1/2 inches. Measure yours instead of assuming.
- Lip length can depend on door thickness, frame depth and trim. Measure the old lip before ordering.
- A latch that misses the strike usually points to a door that has moved. Check the hinges and the gaps before anyone moves or files the strike.
- On a latch with a small second plunger, the plate should hold that plunger in when the door is closed. If it drops into the opening, have the door looked at.
- Don't cut, file or drill a fire-labeled frame or its strike yourself.
First distinction
A strike has to match the lock and the frame
A strike's lip catches the latch as the door swings shut and guides it in. The opening holds the latch or bolt so the door stays closed and sits snug against the stop, the raised edge of the frame the door closes against. The plate also takes the wear, so the latch rubs on a replaceable part and not on the frame.
The lock decides the openings. A cylindrical lock (the kind with a lever through a round hole in the door) needs one opening for its latch. A mortise lock (a rectangular lock body set into the door edge) can need a second opening for a deadbolt, and sometimes more.
The frame decides the outline. A steel frame usually arrives from the factory with a cutout and threaded screw holes already made for one size of strike. A wood frame is often cut on site to whatever plate the installer had. Either way, the easy replacement has the same outline and screw spacing as the old plate.
Sorting table
Strike plate types and where each one goes
Names vary between catalogs, so sort by what you see on the frame. Any of the lipped kinds below can also be had with a longer lip, sold as an extended-lip strike.
An electric strike is a different part: a powered unit that replaces the strike plate and needs a deeper frame pocket and wiring. See how to choose an electric strike and the electric strike installation guide. Know the maker of your lock? See Schlage strike plates for that maker's strikes, sizes and templates.
| Kind | What it looks like | Where you usually find it | What it has to match |
|---|---|---|---|
| ASA strike, also sold as an ANSI strike | A tall rectangular plate with square corners, a screw at each end and a curved lip | Steel (hollow metal) frames, and wood frames on commercial doors, with cylindrical or mortise locks | The lock type. A strike for a mortise lock with a deadbolt has an opening for each bolt |
| T strike | A shorter plate whose lip is narrower than its body, so the outline is a T | Wood frames and some steel frames, with cylindrical locks | A cutout made for a T strike. It will not fill an ASA cutout without a filler plate |
| Full-lip strike | A small plate whose lip runs its full height, with square or rounded corners | Wood frames, with lighter-duty cylindrical locks and latches | The corner shape and the recess already cut in the jamb |
| Deadbolt strike | A flat plate with no lip and one rectangular opening, often with a box behind it | Above the latch strike, wherever a separate deadbolt is fitted | The bolt's size and how far it projects. A thrown bolt needs no lip to guide it |
| Storefront strike | A flat or nearly flat plate on a narrow aluminum jamb | Glass and aluminum storefront doors | The storefront latch or deadlock. These normally don't interchange with ASA strikes |
Lip length
Lip length, and why it depends on the frame and trim
The lip is the curved tongue that sticks out past the frame toward the closing door. The latch should touch the lip first and ride up it into the opening. If the lip is too short, the latch hits the edge of the frame or the trim instead, and you will see a gouge there.
How long the lip needs to be depends on how far the latch sits from the frame's edge. A thicker door, a deeper frame, or thick trim or casing around a wood frame can all call for a longer lip. A lip that is too long sticks out and catches clothing and carts.
Many strikes are made for either a left-hand or a right-hand door, so note which way yours swings. Makers also measure the lip differently (often from the middle of the screw holes to the tip), so compare against the maker's drawing, not just a ruler.
Before ordering
What to measure before ordering a strike
Take the old plate off if you can and measure both the plate and the cutout.
If the whole door is being replaced, see how to measure a commercial replacement door. For how frames differ, see the door frame types guide.
| What to record | How | Why it matters |
|---|---|---|
| Plate height and width | Top to bottom, and side to side without the lip | Steel frames are cut for a small set of standard heights, so the old plate's height tells you what the cutout takes. Wood and aluminum frames vary, so measure the plate you have |
| Corner shape | Square, or rounded, and roughly how rounded | A square plate won't sit in a rounded recess, and a rounded plate leaves gaps in a square one |
| Screw spacing | Center of one screw hole to the center of the other | In a steel frame the holes are threaded at the factory and can't easily be shifted |
| Lip length (how far the lip sticks out) | Often from the middle of the screw holes to the tip of the lip. Check the maker's drawing | It has to reach past the frame edge and any trim. See the section above |
| Door thickness and where the door sits | Across the door edge, then from the stop to the near edge of the strike cutout | The steel door standard covers doors 1-3/4 and 1-3/8 inches thick. A thicker door can move the latch and change the lip you need |
| The lock and the frame | Lock type, any name or number on the lock's edge plate, and wood, steel or aluminum frame | The lock decides the openings in the plate. The frame decides the screws and the recess |
Behind the plate
Dust boxes and frame reinforcement
A strike is only as solid as what its screws go into. In a steel frame the screws go into a metal plate hidden inside the frame, called a strike reinforcement. If those threads strip, a larger screw is not the fix. A technician can repair the threads or the reinforcement.
Behind the reinforcement there is often a dust box. In a steel frame it is a metal cover, also called a grout guard, that keeps grout or mortar out of the screw holes and the latch pocket when the frame is filled. If a latch that used to seat fully now stops short, a pocket blocked by grout, paint or debris is one thing to look for.
Fire labels
Strikes on fire-rated frames
A fire-rated opening is normally marked by a label on the door, and sometimes on the frame too. The usual places are the hinge edge of the door and the frame between the hinges. If there is a label, or a painted-over plate where one would be, treat the opening as rated.
On a rated opening, don't file the strike opening larger, cut the frame, drill new holes or swap in a different kind of strike yourself. That includes replacing a plain strike with an electric one. On a labeled opening the door, frame and hardware are meant to work together, so a change to one part can affect the rating. Work on those openings belongs to a qualified technician.
See the fire-rated door requirements guide for the opening as a whole.
Troubleshooting
What a worn or misaligned strike looks like
Start with the door, not the strike. A strike is screwed to the frame and rarely moves on its own. Doors drop on loose or worn hinges, and a door that drops takes the latch with it. Tighten any loose hinge and strike screws, clear the strike opening, then find your symptom.
For the wider diagnosis, see why a commercial door won't close or latch. If a deadbolt is the part that won't seat, see the commercial deadbolt guide.
| What you see | What it usually points to | First check |
|---|---|---|
| The door closes but the latch doesn't catch, and a push opens it | The latch is landing above or below the opening, often because the door has sagged. Or the door isn't closing far enough for the latch to reach | Shiny rub marks on the plate show where the latch lands. Compare the gap along the top of the door from hinge side to latch side |
| The door latches but rattles when pushed | Slack between the latch and the edge of the opening. Worn or missing rubber bumpers or seals on the stop can cause it, and so can a strike set too far from the stop | Whether the bumpers or seals are still there, then how far the door moves with the latch engaged |
| You have to push or pull hard to make it latch | The latch is reaching the opening late. New weatherstripping, a warped door, a strike set too close to the stop, or a weak door closer can all do it | Whether the door meets the stop evenly from top to bottom, and what changed recently |
| The latch scrapes or bangs before it reaches the plate | A lip that is too short or bent, or a latch that is sticking and slow to retract | Gouges on the frame edge or trim next to the lip. Work the latch by hand with the door open |
| The small second plunger beside the latch (this is what makes it a deadlatch) drops into the strike opening | A wrong strike, an opening that has been filed larger, or too wide a gap between door and frame. The latch can then usually be pushed back from outside | With the door closed, look into the gap with a flashlight. The plate should be holding the plunger in. That locks the main latch against end pressure, so it resists being pushed back with a card or a tool |
| The plate is loose, bent or cracked, or its screws spin | Stripped threads, a failed reinforcement, a split wood jamb, or damage from forcing the door | Whether the screws tighten at all, and any split in the wood or dent in the frame |
Who does what
What to leave to a locksmith, and what to tell them
Tightening screws, clearing the opening and, on a door with no fire label, replacing a plate with an identical one in a wood frame are fair game. These jobs are not:
When you call, give the measurements above, say whether the frame is steel, wood or aluminum and whether there is a fire label, and describe what the latch does when the door closes. A photo of the strike and one of the door edge helps.
- Cutting or enlarging a strike cutout in a steel or aluminum frame, or repairing stripped threads or reinforcement
- Anything on a fire-labeled door or frame beyond tightening a screw
- Moving a strike, or changing from one kind of strike to another
- A deadlatch plunger that drops into the opening
- Strikes for exit devices, and anything involving an electric strike or its wiring
- A door that has sagged or a frame that has shifted
If the door still won't latch
Elwin Security installs, repairs and replaces strike plates, locks and commercial door hardware for commercial and multifamily properties in the San Francisco Bay Area. Calls are answered 8:00 AM-8:00 PM daily at (408) 539-0535.
Common questions
Commercial strike plate questions
What size is a commercial door strike plate?
In steel frames, 4-7/8 inches is the most common strike height, followed by 2-3/4 and 3-1/2 inches. Measure the plate you have, because the cutout differs by door thickness and frame type.
Are strike plates universal?
No. A strike has to match the lock's latch or bolts and the cutout in the frame. Plates of the same outside size can differ in openings, lip and handing (left-hand or right-hand door), so match the old plate or the lock maker's template.
How do I measure strike lip length?
Many makers measure from the middle of the screw holes to the tip of the lip. Check the maker's drawing, because makers differ.
Can I move or file the strike so the door latches?
It usually isn't the right first step. A latch that has stopped lining up usually points to a door that has moved, so check the hinges and gaps first. On a fire-labeled frame, don't file, cut or drill at all.
Sources and further reading
These sources back up the general guidance. Your building and the people who approve the work decide the details for your doors.