Resource — Trade Fabrication Guide

How Aluminium Shopfronts and Commercial Doors Are Fabricated

An aluminium shopfront is fabricated by cutting extruded profiles (such as Jack Aluminium JD47) to a cutting list on a double-mitre saw, machining preps for locks, hinges, pivots and transoms, joining the corners with mechanical cleats or crimps — never welding — and squaring the assembled frame on a jig before beads, gaskets and hardware go on. The frame itself is a job measured in workshop hours; the calendar lead time is mostly engineering, powder coating and glass. This guide walks through every stage as we run it in our Warrington workshop — and covers when it makes more sense to buy the frame fabricated to your sizes.

By Stephen Chappell, Managing Director, Kingsland Fabrications. Updated 3 July 2026. Trade-only — we supply and fabricate; we don't install.

The short answer: the eight stages of shopfront fabrication

Fabricating an aluminium shopfront means turning extruded bar-length profile into a finished, square, hardware-ready frame: survey sizes are engineered into a cutting list, each profile is cut and machined, the corners are mechanically joined, and the whole assembly is squared on a jig before gaskets, beads and hardware complete the kit. Eight stages, in the order they happen on our workshop floor:

Survey sizes

Brick-to-brick structural opening sizes measured at three points, plus hardware spec, RAL colour, threshold detail and door positions.

Engineering and CAD approval

The survey is engineered in LogiKal into an elevation drawing and cutting list. CAD drawings are issued with the quote for sign-off before anything is cut.

Cutting

A double-mitre saw cuts each extruded profile to length — 45° mitres and 90° square ends — from the approved cutting list.

Machining and prepping

Lock cases, hinge and pivot preps, spindle holes, transom preps and drainage slots are machined on the CNC before assembly.

Corner joining

Corners are joined with mechanical cleats or hydraulic crimps. UK commercial aluminium is never welded.

Jig assembly

The frame is assembled and clamped square on a flat jig, with the diagonals compared to prove squareness before it moves on.

Gaskets, beads and hardware

EPDM gaskets run into the grooves, glazing beads are cut and matched per opening, and hardware is fitted or prepped to the manufacturer’s template.

QC and dispatch

Every item is checked against the cutting list, operated, inspected, labelled by opening reference, then braced, wrapped and palletised.

One correction before the detail, because a lot of what ranks for this question was written for other markets: UK commercial aluminium systems are mechanically joined, not welded. Welding anneals the heat-treated alloy around the joint, distorts the slim profile walls and burns the powder-coated finish — so no UK systems house designs for it. If a guide describes welding a shopfront frame, it isn't describing UK trade practice.

And if you searched for how an aluminum storefront is fabricated — the US spelling — the logic below is the same; the framing systems, terminology and glazing standards differ.

Survey sizes, engineering and the cutting list

Fabrication starts before any metal is touched. What the fabricator needs from the installer is the brick-to-brick structural opening — width and height each measured at three points, because openings are rarely square — plus the hardware spec, the RAL colour, the threshold detail and where the doors sit in the frontage. If you're pricing a replacement on an existing frontage, our replacement survey checklist covers exactly what to record on site.

The frame is deliberately made around 10–15mm under the structural opening. That fitting deduction is what gives the installer a packing and adjustment gap — a frame made to the exact opening size would never go in.

Those sizes are engineered in LogiKal, which converts the approved elevation into a cutting list and the machining program for the CNC. We issue CAD drawings with every quote for sign-off before fabrication starts, because the economics of errors are brutally asymmetric: a mistake caught on a drawing costs nothing to fix; the same mistake caught on site costs a remake and a lost fitting day.

Cutting and machining the profile

The profile arrives from the systems house as extruded bar length. A double-mitre saw cuts each piece to the cutting list — two heads cut both ends in a single pass, at 45° for mitred corners or 90° for square-cut junctions — using negative-rake TCT blades made for aluminium, holding cut lengths to a millimetre or better. Cutting both ends in one pass is what keeps opposite frame members genuinely identical, which matters later on the jig.

Machining happens next, and the order is not optional: lock cases, hinge and pivot preps, spindle holes, transom preps and drainage slots are all cut on the CNC before assembly, because you cannot get a router into an assembled frame. Every prep is machined to the hardware manufacturer's template, so the lock case, the keeps and the pivots land exactly where the hardware expects them.

This is also where cheap fabrication goes wrong. Hand-drilled hardware preps are the most common defect on site-fabricated doors — a lock case a few millimetres out of line means a door that catches, a cylinder that binds and a call-back that eats the margin on the job. Machined preps are not a luxury; they're the difference between a doorset and a problem.

Crimped vs cleated corners: which is stronger and when is each used?

Both are mechanical joints — the difference is how the cleat is held in the profile, and it decides which parts of a shopfront each is used on.

Cleated corners

Extruded aluminium corner cleats sit inside the profile chambers across the mitre and are mechanically pinned or screwed in place, with the joint sealed for weathering. This is the standard joint for shopfront framing and fixed screens: strong, serviceable and quick to assemble accurately.

Crimped corners

A hydraulic crimping press deforms the profile wall onto a serrated cleat, locking the joint permanently. It's the stronger of the two — which is why it's used on door leaves, the one part of a shopfront that takes slamming loads and floor-spring torque every day of its life.

The decision logic is simple: frames and screens are cleated — the joint is adequate for a fixed assembly and can be taken apart if it ever needs to be. Door leaves are crimped — a leaf on a floor spring cycles thousands of times a year and needs the rigidity of a permanent joint. Neither is welded. For the joint terminology in context, the fabrication section of our glossary covers cleats, crimps and the rest of the workshop vocabulary.

What is a fabrication jig and why does it matter?

A jig is a flat, square reference surface the frame is assembled and clamped on. Squareness is proven by comparing the diagonals: if the two corner-to-corner measurements match, the frame is square; if they differ, it has racked. It's a simple check, and it's the one that decides whether the frame fits on site.

Here's why it matters more than the saw: a frame can be in tolerance on every single cut and still rack into a parallelogram when it's joined off-jig. Nothing about the individual parts is wrong — the geometry of the assembly is. That is the single most common reason a "made-to-measure" frame fails its first fit, and it's invisible until the installer offers the frame up to the opening.

Every Kingsland kit is assembled and checked on the jig before dispatch — 99% of our products fit first time, with no site modifications needed.

Fabricator checking an assembled aluminium door frame for square in the Kingsland workshop before dispatch

"A frame can pass every measurement as parts and still be wrong as an assembly. The jig is where we find that out — not your fitter, on site, with the old frontage already out of the hole."

— Stephen Chappell, Managing Director

Gaskets, beads, hardware and glazing prep

With the frame square, the sealing and hardware layers go on. EPDM gaskets are run into the profile grooves, and snap-in glazing beads are cut and matched to each opening — supplied labelled to the aperture they belong to, so nothing gets shuffled on site.

Hardware is either fitted or prepped, depending on the item: floor-spring and pivot preps, transom closer preps, lock cases, keeps and panic hardware preps — all machined on the CNC to the hardware manufacturer's template, as covered above. On the glazing side, the JD47 shopfront system accepts 6–28mm infills, which covers everything from a single-glazed retrofit to a 28mm double-glazed unit in one system. Door leaves are glazed and beaded in our workshop where specified, so they arrive ready to hang; display-zone glass on a larger frontage is commonly glazed on site by the shopfitter. The glazing section of the glossary unpacks the spec language.

Quality control, kitting and delivery

Before anything is wrapped, each order goes through a final check:

Cut lengths verified against the cutting list, so what was engineered is what was made.
Diagonals checked on the jig — the squareness proof described above, done as a final gate, not just during assembly.
Hardware operated — locks thrown, hinges swung, closers cycled — before it's packed, not after it's fitted.
Finish inspected for coating defects and handling marks while a fix is still a workshop job.
Every item labelled by opening reference so the kit sorts itself on site.

The kit that leaves the workshop is the complete job: fabricated frames, beads, gaskets, fixings and the CAD drawing — everything the installer needs, delivered palletised throughout mainland Britain from our Warrington workshop.

One honest note on what QC can't fully control: transport. A frame that left the jig square can rack in transit if it's badly restrained — it's a real failure mode, which is exactly why frames are braced and wrapped before they're loaded, and why every kit is photographed and checked before dispatch.

How long does fabricating a shopfront take?

Two different clocks answer that question. The workshop clock is short: once the profile is coated and the cutting list is loaded, a single-door shopfront frame is a job measured in hours on the saw, the CNC and the jig — not days. The calendar clock is what you plan around: our standard lead time is 21 working days from approved sizes, and most of that is the engineering sign-off, powder coating and glass procurement that happen around the fabrication itself.

What moves the calendar: a non-stock RAL colour adds a coating cycle, special glass adds procurement time, and unusual hardware can hold an otherwise finished frame. If a job is genuinely time-critical — a failed frontage that has to be secured — tell us at the quote stage and we'll tell you straight what turnaround is achievable; our FAQs cover rush orders in more detail.

Should you fabricate your own shopfronts, or buy them fabricated to size?

Everything described above needs a double-mitre saw, a CNC machining centre, a crimping press, assembly jigs, extraction, bar-length profile stock and — the part that's hardest to buy — a trained fabricator who does this every day. That's realistically tens of thousands of pounds of equipment before the first frame, plus the ongoing cost of keeping the skills and the stock in the building. In-house fabrication makes sense at volume; below it, the kit sits idle between jobs while it depreciates.

For most installers, shopfitters and maintenance companies, the honest answer is to buy fabricated: send survey sizes, get back a jig-tested kit that fits first time, and keep your crew fitting — the work that actually pays them. That's the supply-only model, and we've written up what supply-only means in practice and how our supply-only service works if you want the detail.

We would say that, obviously — supply-only fabrication is our business. But it's also the conclusion the process itself points to: fabrication rewards repetition, tooling and jigs, and those are exactly the things a workshop that does nothing else can hold to a tighter standard than a fitting crew with a saw in the van.

Frequently asked questions

Are aluminium shopfronts welded together?

No. UK commercial aluminium systems are mechanically joined with corner cleats or hydraulic crimps. Welding anneals the heat-treated alloy, distorts the profile and destroys the powder-coated finish — guides describing welded shopfronts are describing practice in other markets, not how UK trade fabrication works.

What tools do you need to fabricate an aluminium shopfront?

At minimum: a double-mitre saw, a copy router or CNC machining centre for hardware preps, a corner crimping press, assembly jigs, extraction and compressed air. Realistically tens of thousands of pounds of equipment before wages, training and profile stock — which is why most installers buy frames fabricated supply-only instead.

What aluminium systems are shopfronts fabricated from?

Commercial systems supplied as extruded bar length by systems houses — Jack Aluminium (JD47, TD68), AluK, Kawneer, Senior Architectural Systems, Smart Systems and others. The systems house extrudes the profile; a trade fabricator like Kingsland cuts, machines and assembles it into finished shopfronts and doorsets.

What tolerance is a fabricated shopfront frame made to?

Cut lengths are held to a millimetre or better, and the assembled frame is checked square on a jig by comparing its diagonals. The frame itself is made around 10–15mm under the structural opening size to leave a fitting and packing gap for the installer.

Can I buy an aluminium shopfront fabricated to my sizes?

Yes — that is exactly what a supply-only trade fabricator does. Send survey sizes, hardware spec and colour; you get back a jig-tested kit with beads, gaskets, fixings and a CAD drawing, delivered palletised throughout mainland Britain, typically within a 21 working day standard lead time. You fit it on site; the fabricator carries the fabrication tolerance risk.

If you'd rather fit shopfronts than fabricate them, talk to us. Call 01925 500 295, email sales@kingslandfabrications.co.uk or send sizes, photos or a sketch through the contact form and we'll talk the job through — a quote with CAD drawings follows within 24 hours if you want one.