Window Profile: Parts, Accessories and Fabrication Machines

A window profile is never a single bar. One window is built from a set of profiles (outer frame, sash, mullion, glazing bead, screen), a kit of accessories (corner cleats, gaskets, corner brace plates, handles) and a few workshop machines (double-head saw, punching dies, corner crimping machine). This page explains each one. For the series we extrude, see our aluminum window profiles.

Profiles in a window profile set

wall opening

Outer frame

The profile fixed into the wall opening. It carries the whole window, holds the drainage path and gives the sash something to close against. Its depth is usually what a series is named after, for example a 55 or 70 series.

Sash

The part that opens. Sash profiles hold the glass and the hardware groove for hinges, locking points and the handle. Casement, sliding and tilt-and-slide windows each use a different sash section.

mullion (vertical) / transom (horizontal)

Mullion and transom

A mullion divides the frame vertically and a transom divides it horizontally, so one frame can hold several sashes or fixed lights. Their ends are milled to fit the frame contour.

beadglass

Glazing bead

A small clip-in profile that clamps the glass into the frame or sash. The bead size is chosen to match the glass thickness, which is why one series lists several beads.

Screen profile

The light frame that carries the insect mesh. It can be a separate sash, or built into the window on screen-integrated series.

Accessories needed with the profiles

Aluminum corner cleat joining two mitred profiles

Corner cleat

An aluminum angle piece pushed into the hollow chambers of two mitred profiles. It is what actually joins the corner once the profile wall is crimped or pinned onto it.

Steel corner plate for aluminum window frames

Corner brace plate

A thin flat plate set in the outer groove across the mitre. It keeps the two faces flush so the corner shows no step, and works together with the cleat.

Sealing strip for aluminum windows and doors

Gaskets and sealing strips

EPDM rubber gaskets sit between glass and profile and between sash and frame. Sliding sashes use brush-type sealing strips. Both keep water and air out and stop rattling.

Black handle and lock on a slim aluminum door

Handle and hardware

The handle drives the locking points around the sash. Hinges or friction stays, locking points and rollers for sliding sashes are chosen to match the hardware groove of the profile.

Double-wheel roller for sliding windows and doors

Rollers

Rollers carry a sliding sash along the track. They are sized to the sash weight and to the roller groove of the profile.

MT Flying can pack hardware, seals, hinges, screws and corner pieces together with the profiles. See our guide to buying aluminum window profiles from China.

Machines used to fabricate a window

length set by the moving head

Double-head saw

Two saw heads cut both ends of a bar in one pass, normally at 45 degrees for frame and sash corners. One head is fixed and the other moves to set the length.

Punching dies

A press fitted with dies made for one profile series. It punches drainage slots, cleat fixing points and hardware cut-outs quickly and in the same place every time.

stepped end fits the frame contour

End milling machine

Cuts the stepped end of a mullion or transom so it fits tightly against the frame profile in a T-joint.

two knives pressthe wall into the cleat

Corner crimping machine

Presses the profile wall into the grooves of the corner cleat from two sides, locking the mitred corner. Most aluminum window corners are joined mechanically, not welded.

How one window is made, step by step

  1. Cut frame, sash and bead profiles to length on the double-head saw.
  2. Punch or mill drainage slots, hardware cut-outs and mullion ends.
  3. Insert corner cleats and brace plates, with adhesive on the mitre faces.
  4. Crimp the four corners on the corner crimping machine.
  5. Fit gaskets and hardware, then hang the sash in the frame.
  6. Set the glass and clip in the glazing beads. Fit the screen last.

Drawings on this page are simplified diagrams, not sections of a specific series.

Common questions

What does a window profile set include?

The outer frame, the sash, mullions or transoms, glazing beads and, where fitted, the insect screen profile. Corner cleats, gaskets, corner brace plates and hardware such as handles are accessories ordered with the profiles.

Which machines do I need to fabricate aluminum windows?

At minimum a double-head mitre saw, a punching press with dies made for your profile series (or a copy router), an end milling machine if the design has mullions, and a corner crimping machine.

Why do punching dies need to match the profile series?

Punching dies are designed according to the profile shape and the required processing positions. They are used to make drainage holes, fixing holes, hardware openings and other cut-outs accurately. Different profiles may require different dies. However, some profiles can share the same dies if their processing requirements are similar. Adjustable punching tools or CNC machines can also be used for multiple profile series.

Are aluminum window corners welded?

Most aluminum window corners are mechanically joined rather than welded. For many casement window systems, profiles are cut at 45 degrees and connected using corner cleats and a corner crimping machine. Other systems use screws or mechanical connectors, and some profiles are cut at 90 degrees. The assembly method depends on the specific window system and profile design.

Need window profiles with the matching accessories?

Send us your drawing or window schedule. We reply with sections, the accessory list, price and lead time.

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