Crate spec ticket
| Members | Skid base, sloped frames, ridge rail, bearing blocks |
|---|---|
| Load rests on | Padded bearing strips along the foot |
| Faces | Two sloped frames, one each side |
| Sheet pack | Interleaved with foam or paper |
| Marks | Fragile, this side up, tip indicator |
| Quote needs | Sheet sizes, count, thickness, destination |
Why flat sheets travel on edge
A sheet of glass or stone is strong in compression along its plane and weak in bending across its face. Laid flat and stacked, it takes bending from its own weight and from anything riding on top. Stood on edge and supported along its face, the same sheet carries a good deal more without cracking.
That is the reason for the A. The two sloped faces give each sheet something to lean on, and the angle spreads the weight into the base. A vertical rack would work in theory, but a leaning load is steadier and sheds less side movement as the crate rocks.
How the crate is built
The base is a wide skid with side rails, wider at the foot than the stack itself, because the footprint sets the tip resistance. On the base sit two sloped frames, joined at the ridge by a rail and braced across the ends. Padded bearing strips along the foot carry the sheets' weight, and the frames' faces are lined with foam or felt.
Sheets lie against the frames in packs, separated by interleaving material such as paper or foam. Straps cross the top of the pack or run through blocks, so sheets cannot slide forward. The ends close with end panels, and a lid or cap tops the ridge.
Loads that need it
Architectural glass, tempered panels, mirrors, large display glass, granite and quartz slabs, marble, stainless sheets, solar panels and big framed artwork are typical. Our pages on glass and stone slabs go through the specific padding and strap approach for each material.
A-frame crates are not for dense, heavy blocks. A stone slab can weigh a great deal per square foot of face, so the weight has to be named on the quote, and the base is sized to it. A single heavy slab may be better in a purpose-built case.
- Glass and mirror packs
- Granite, quartz and marble slabs
- Large flat panels and solar modules
- Framed artwork on edge
Where A-frame crates fail
The usual cause is a load that can shift. If a pack is not strapped to the frame, a stop sends the top sheets forward into the lean. Hard bearing strips chip edges. A narrow footprint tips the crate when the forklift turns.
We counter each one. Strapping or blocking goes on every pack, bearing strips are padded, and the skid is wide enough to hold the crate steady, with a tip indicator and a centre-of-gravity mark on each face. The crate must stay upright, so an A-frame cannot be stacked and must travel marked this side up.
Tare, cube and export
An A-frame wastes a little cube at the ridge, because the sloped faces leave an air gap under the peak. In exchange it carries brittle freight that nothing else can. Tare depends on how heavily the frames are built, and stone packs call for much stouter timber than glass.
The skid and frame members are solid lumber, so for export they take heat treatment and the IPPC stamp on a minimum of two opposite sides, per NELMA. Any sheet or plywood panel closing the ends is exempt from the treatment rule. We list which parts are which on the written spec.
A-frame versus a sheathed crate
A sheathed box can carry a single glass sheet laid flat with a foam bed, and for a small piece that is simple. The moment you have a pack of large sheets, a flat stack puts weight on the bottom sheet. The A-frame lets each sheet stand and keeps handling to one side.
Pick the A-frame when sheets are large, many or brittle. Pick sheathed when it is one small piece.
Handling and unloading on site
Unloading an A-frame takes planning. Position the crate on level ground, with a forklift of suitable capacity and a clear aisle, and never open one face while the other is unsupported. Remove straps from the top pack first, then lift sheets out one at a time with vacuum lifters, A-frame carts or padded clamps, starting from the front sheet.
Keep the crate upright until the last sheet is out. Inspect edges for chips, corners for shells and surfaces for scratches, and record anything before the sheets leave the frame. Empty A-frames fold or break down for return where the shipper has asked for it, which spares the cost of buying new ones each run.
What to send us
Send each sheet's size and thickness in inches, how many are in the pack, the combined gross weight in pounds and the destination. Tell us the finish: polished faces need an interleave that will not scratch. We keep the spec on file, so a repeat run of slabs ships the same.
Questions buyers ask
Can a pallet-size sheet pack ship in an A-frame?
Yes, provided the pack is strapped to the frames and the base is wide enough to resist tipping.
Can an A-frame crate be stacked?
No. It has to travel upright and be marked this side up, with a tip indicator on the faces.
What goes between the sheets?
Foam, paper or felt, depending on the surface. Polished stone and coated glass need a clean, non-abrasive interleave.
Is the A-frame stamped for export?
The lumber parts are heat-treated and stamped on two opposite sides. Plywood end closures are exempt.