Rigid-wall military shelters are built from aluminium-skinned sandwich panels held together by an extruded aluminium frame. Nine profile families do most of the work: door frames, window frames, roof and floor beams, side beams, outer edge trims, aperture frames, small access-door frames and custom fittings. This page explains what each profile does, which alloys and tempers suit it, and what to specify when you order. Metline supplies shelter extrusions to drawing for shelter builders worldwide.
A typical rigid-wall tactical shelter is a box about the size of an ISO 20 ft or 10 ft container, made of sandwich panels with aluminium skins and a honeycomb or foam core. Extruded aluminium sections are bonded or welded round every panel edge, joined at the corners and fitted with doors, hatches and cable entry plates.
The frame gives the panels their edge strength, carries lifting and stacking loads to the corner fittings, and seals the joints against rain, sand and electromagnetic leakage. Because the shelter is often carried on a truck, lifted by helicopter or shipped as an ISO container, every kilogram counts, which is why aluminium extrusions are used rather than steel sections.
ASTM E1976 describes a common non-expandable shelter of this type: aluminium-faced honeycomb panels framed with bonded aluminium extrusions, with lifting, stacking and racking loads taken from ISO 1496-1. Expandable shelters add hinged or sliding wall sections, which call for additional hinge, seal and guide profiles.
| No. | Profile | Function | Typical alloy and temper |
|---|---|---|---|
| 1 | Main door frame (type A) | Frames the personnel door; carries hinges, locks and the door seal | 6061-T6 or 6082-T6 |
| 2 | Main door frame (type B) | Lighter alternative section with a wider sealing flange | 6061-T6 or 6063-T6 |
| 3 | Window frame | Holds glazing or blackout panels and their gaskets | 6063-T5 or T6 |
| 4 | Roof and floor beam | Edge members that carry roof snow loads, floor equipment loads and racking | 6061-T6 or 6082-T6 |
| 5 | Side beam | Vertical and horizontal wall edge members joining wall panels to roof and floor | 6061-T6 or 6005A-T6 |
| 6 | Outer edge trim | Closes and protects the external panel joints; forms a drip edge | 6063-T5 |
| 7 | Aperture frame | Frames openings for air-conditioning units, cable entry panels and vents | 6063-T6 or 6061-T6 |
| 8 | Small door frame | Frames service hatches and equipment access doors | 6063-T6 |
| 9 | Custom fittings | Flat bars, angles, channels and special sections for brackets, rails and racks | 6061-T6, 6063-T5 |
Example section sizes taken from typical shelter designs are shown below. They illustrate the scale of the profiles; actual dimensions always follow the customer drawing.
| Section | a (mm) | b (mm) | c (mm) | d (mm) |
|---|---|---|---|---|
| Door frame, type A | 50 | 40 | 3 | 3.5 |
| Door frame, type B | 70 | 40 | 2 | 2 |
| Window frame | 50 | 38 | 2 | — |
| Beam, light | 38 | 38 | 2 | — |
| Beam, heavy | 40 | 40 | 3 | — |
| Flat fitting bar | 25 | 5 | — | — |
| Flat fitting bar, small | 20 | 4 | — | — |
| Alloy and temper | Typical tensile / yield (MPa) | Strengths | Best for |
|---|---|---|---|
| 6063-T5 | ≈ 185 / 145 | Excellent extrudability and surface finish; complex thin sections | Trims, window frames, aperture frames |
| 6063-T6 | ≈ 240 / 215 | Higher strength while keeping good finish | Small door frames, light frames |
| 6061-T6 | ≈ 310 / 275 | High strength, good toughness, weldable | Door frames, beams, corner members |
| 6082-T6 | ≈ 310 / 260 (EN 755-2 min. about 290 / 250 for thin walls) | Strong structural alloy, common under EN standards | Beams, side members, load-bearing frames |
| 6005A-T6 | ≈ 285 / 240 | Good strength with better extrudability than 6082 | Larger hollow side beams |
Typical values; design to the minimums of EN 755-2 or ASTM B221 for the wall thickness and temper ordered.
Frame profiles bonded to sandwich skins need clean, pretreated surfaces and a bonding flange wide enough for the adhesive. Specify the pretreatment (for example a chromate-free conversion coat) so the bond survives humidity cycling.
Shielded shelters rely on continuous metal-to-metal contact at every joint. Profiles need flat, conductive gasket seats and a compatible surface finish; anodising insulates, so contact faces are usually left conductive or conversion coated.
Door and window profiles carry gasket grooves sized to the chosen seal. Tolerances on groove width and depth matter more than overall size, so mark them as critical on the drawing.
Lifting, stacking and racking loads pass through the frame to the corner fittings. Beams and side members near the corners are usually 6061-T6 or 6082-T6 with heavier walls.
Steel corner castings and fasteners must be isolated from the aluminium frame with sealants, washers or coatings, particularly for coastal and shipborne use.
Shelters are typically qualified for heat, cold, rain, sand, salt fog and vibration under MIL-STD-810 methods. Profile finish and sealing details should be chosen with these tests in mind.
New sections need an extrusion die. Send the drawing early so the section can be reviewed for extrudability (wall thickness ratios, tongue ratios and sharp corners) before the die is cut. Small design changes at this stage often cut cost and improve straightness.
6061-T6 or 6082-T6 for load-bearing beams, door frames and corner members; 6063-T5 or T6 for trims, window frames and other complex, lighter sections where finish and extrudability matter.
Yes. Profiles are extruded to your drawing. Send the section, alloy, temper and critical dimensions; new sections need a die, which we review for extrudability before production.
It depends on the joint. Bonded and EMI contact faces are usually conversion coated or left bare; exposed trims are anodised, powder coated or primed for the shelter paint system.
Both. Many rigid-wall shelters bond the extrusions to the panel skins and weld or rivet the frame corners. 6061, 6082 and 6063 all weld with ER4043 or ER5356 filler, with some strength loss in the heat-affected zone.
Profiles are usually supplied in mill lengths up to about 6 m, or cut to exact length, mitred and drilled to drawing.
Send your profile drawings, alloys, lengths and quantities. Our team will reply with a section review and quotation.
