Why Aluminum Frames Deserve a Separate Conversation
This post covers the specific challenges of installing an electric strike in an aluminum storefront or narrow-stile frame — a job that looks routine on paper but catches even experienced technicians off guard. If you work access control in commercial buildings, schools, healthcare facilities, or retail storefronts, this is the frame type most likely to result in a botched cutout and an expensive callback.
Aluminum frames account for a significant share of access control openings in commercial construction today. Yet the material punishes mistakes in ways that hollow metal simply does not. A miscut in hollow metal can often be patched or ground flat. A miscut in an aluminum extrusion is visible, structural, and difficult to recover from. The margin for error is narrow — in more than one sense of the word.
What Makes Aluminum Different Before You Pick Up a Tool
The Pocket Is Not What You Expect
Hollow metal frames come with a standard 4-7/8-inch strike pocket already formed at the factory. Aluminum storefront frames do not. The cavity behind the stop is determined by the extrusion profile, and that profile varies by manufacturer and frame series. Before you assume anything about pocket depth, pull the frame spec or measure the actual cavity.
More importantly: glass is frequently sitting immediately behind the stop in aluminum storefront frames. That glass chunk intrudes directly into the area where your strike body needs to go. If you skip the site survey and start cutting, you will hit it. Measure twice, then confirm what is behind the frame before any material is removed.
The Blade Stop Problem
Many aluminum frames use a blade stop — a thin aluminum projection that runs vertically along the frame face where the door meets the frame. Surface-mounted electric strikes require that blade stop to be cut or notched to accommodate the strike body length. The cut must be clean and sized correctly to the specific strike model you are installing. A ragged or oversized cut undermines both the appearance and the structural support the stop provides.
Use the manufacturer-supplied template whenever one is available. Take your time on the layout. Tape the template before marking or punching anything.
Tapping Threads Into Aluminum
Unlike hollow metal, aluminum frame extrusions typically do not have pre-tapped holes. Mounting holes for the strike body must be drilled and tapped. Aluminum is soft enough that the process goes quickly — but that also means it strips easily if you overtorque the mounting screws. Use the correct tap size for the fasteners supplied with the strike, and do not substitute hardware. Many strikes ship with 10-32 or similar thread specs; confirm before you tap.
Strike Selection for Aluminum Frame Openings
Surface-Mounted vs. Mortised in Aluminum
Both surface-mounted and mortised electric strikes are used in aluminum frames, but the application logic differs from hollow metal:
- Surface-mounted strikes are common with rim exit devices and half-inch throw latch applications. They attach to the frame face without requiring a deep pocket. The blade stop must still be notched to fit the strike body.
- Mortised strikes require more cavity depth. Confirm the frame pocket can actually accommodate the strike body depth before specifying. Some narrow aluminum frames simply do not have enough material to accept a standard mortised strike without hitting the glass or the structural extrusion behind the stop.
Match the Strike to the Latch
The electric strike you select must match the latch bolt throw, latch geometry, and hardware type on the door. A strike designed for a cylindrical lock with a 3/4-inch latchbolt behaves differently from one designed for a rim exit device or a narrow-stile Adams Rite-style latch. Know what is on the door before you source the strike. DoorwaysPlus carries electric strikes suited to the range of latch and lock types found on aluminum frame openings.
Fail-Secure vs. Fail-Safe: The Code Reality
An electric strike in an aluminum frame is subject to the same fail-mode code considerations as any other opening. Fail-secure strikes (locked when power is off, released when energized) are preferred by code officials because egress is never dependent on electrical power — the occupant uses the mechanical handle to retract the latch regardless of strike state. Fail-safe strikes (unlocked when power is removed) are not fire-listable and require careful justification under life safety codes. Confirm the fail mode with your authority having jurisdiction before the hardware is ordered.
Electrical Considerations at the Frame
Getting power to an electric strike in an aluminum frame requires planning the wire path before the frame is set when possible — or working with the existing extrusion cavities on retrofit jobs. Key points:
- Minimum wire gauge requirements vary by voltage and run length. At 24 VDC, 20-gauge wire is acceptable for runs up to 200 feet; longer runs require heavier gauge. Always calculate run length as the round trip, not one-way.
- Power the strike from a UL 294 Class 2 power-limited supply. Verify input voltage at the strike terminals with a multimeter before connecting — many supplies run slightly above rated output, and exceeding the solenoid rating by more than 10 percent can damage the unit.
- Inductive kickback from the solenoid can cause problems in control circuits over time. Using a plug-in bridge rectifier or a MOV-equipped accessory at the strike is a recognized field practice for protecting the control side of the circuit.
- Coordinate wire routing with Division 26 on new construction. On retrofit, use the frame extrusion cavity as the wire chase where geometry allows; otherwise plan an exposed conduit run to a nearby junction box.
The Site Survey Is Not Optional
Before any aluminum frame electric strike job, a proper site survey should answer these questions:
- What is the frame extrusion profile, and what is the actual cavity depth behind the stop?
- Is glass present behind the stop, and how close is it to where the strike body will sit?
- Does the frame have a blade stop that requires cutting?
- What lock or latch is on the door, and what is the latch throw and geometry?
- Where will power enter the frame, and what is the wire run length to the power supply?
- Is the opening fire-rated or on a fire egress path, and what fail mode is required?
Spending fifteen minutes on these questions before the job starts is what separates a clean installation from a callback — or a ruined frame.
Get the Right Strike Before You Get to the Job
DoorwaysPlus stocks electric strikes suited for aluminum frame openings across a range of latch types, voltages, and fail modes. If you have questions about which strike fits your opening or need help reading a frame profile, our team can help you get it right before anything gets cut.