Bright finish
Polished on the pattern side to a mirror-like shine, usually in 3003. The classic look of toolboxes and truck trim. Supplied with protective film.
Tread plate guide
Aluminium Diamond Plate: Grades, Finishes and Sizes
Aluminium diamond plate (aluminum diamond plate, also called tread plate or checker plate) is sheet or plate rolled with a raised pattern of diamonds or bars on one face for grip, stiffness and a hard-wearing look. It is the standard material for truck and trailer floors, toolboxes, steps, ramps, walkways, wall protection and boat decks. This guide explains which alloy to choose, the difference between bright and mill-finish plate, common sizes and weights, and how to order. Metline supplies aluminium diamond plate in sheet, plate and coil worldwide.
- Alloys
- 3003, 5052, 5086, 5754, 6061
- Tempers
- H14, H22, H32, H114, T6
- Thickness
- About 1.2 – 8 mm
- Standards
- ASTM B632 · EN 1386 · ASTM B209
What is aluminium diamond plate?
Diamond plate is made by passing hot or cold aluminium through a roll engraved with the pattern, which raises the design on one face while the back stays flat. The raised lugs give traction underfoot, hide scratches and dents, and add some stiffness compared with plain sheet of the same base thickness.
The term "diamond plate" is used loosely. In North America it usually means a pattern of elongated raised diamonds (sometimes called "1-bar"). In Europe and Asia the same product is often called tread plate or chequer plate, and other patterns are common: 3-bar and 5-bar (groups of parallel raised bars set at right angles), lentil or "pointer" patterns, and fine stucco or orange-peel embossing for decorative use. All are covered by tread plate standards such as ASTM B632 and EN 1386.
Aluminium replaces steel tread plate where weight and corrosion matter. It weighs about one third as much, does not rust, needs no painting, and keeps a clean appearance for years, which is why it dominates on vehicles, boats and outdoor access structures.
Which alloy of diamond plate do you need?
| Alloy and temper | Character | Typical uses |
|---|---|---|
| 3003-H22 / H14 | Formable, easy to bend and polish; moderate strength; the standard bright tread plate | Toolboxes, wall and corner guards, kick plates, trailer and truck trim, decorative work |
| 5052-H32 / H114 | Stronger and more corrosion resistant; good for welding and saltwater exposure | Boat decks, refrigerated truck floors, oil tanker walkways, humid and coastal sites |
| 5086-H32 / 5754-H114 | Higher-magnesium marine alloys with higher strength | Marine decks, ship stairs, offshore walkways |
| 6061-T6 | Heat-treated for the highest strength of common tread plates; less formable | Load-bearing floors, ramps, stair treads, platforms, trailer floors |
The alloy sets strength, formability and corrosion resistance; the tread pattern affects appearance and grip but not the base properties. Mechanical requirements for each alloy and temper are given in ASTM B632 (US) and EN 1386 with EN 485-2 (Europe); every delivery carries a mill test certificate.
As a quick guide: choose 3003 for bright, formable, decorative and light-duty uses; 5052 when the plate will be in water, salt air or welded; and 6061-T6 when the plate must carry load over a span, such as ramps and access floors. Note that 6061-T6 cracks if bent tightly, so bends should be generous or made in a softer alloy. See also 5052 tread plate for tankers and 3003 tread plate.
Bright, mill-finish, anodised and painted plate
Mill finish
As rolled, with a dull, slightly uneven sheen. Lower cost; used where function matters more than looks, such as floors, platforms and industrial walkways.
Anodised and coloured
Anodising (black, bronze, red, blue and others) adds a hard, coloured oxide layer. Results are most even on alloys and surfaces prepared for anodising.
Painted or powder coated
Applied after cutting for colour matching on vehicles and buildings.
Stucco and other patterns
Stucco embossed or 5-bar patterns for walls, insulation cladding and floors where a different look or grip is wanted.
Protective film
PE or PVC film on the pattern side protects bright and anodised plate during fabrication; remove it soon after installation outdoors.
Common sizes, thicknesses and weights
Typical supply range
- Thickness
- About 1.2 – 8 mm (0.045 – 5/16 in), measured on the base sheet excluding the pattern
- Imperial sheet sizes
- 24 × 96, 48 × 96, 48 × 120, 60 × 120 and 60 × 144 in
- Metric sheet sizes
- 1000 × 2000, 1250 × 2500, 1500 × 3000 mm; width up to about 1850 mm and long lengths to order
- Forms
- Cut sheet, plate, coil and slit strip
- Processing
- Shearing, sawing, laser, plasma and waterjet cutting to size or drawing
The table gives the weight of the flat base sheet for common thicknesses, calculated at 2.73 g/cm³ (3003). The raised pattern adds extra metal on top of this, proportionally more on thin plate, so ask for the mill's tread plate weight table for exact figures.
| Fraction (in) | Decimal (in) | Base weight (lb/ft²) | Base weight (kg/m²) |
|---|---|---|---|
| 3/64 | 0.045 | 0.64 | 3.12 |
| 1/16 | 0.063 | 0.89 | 4.37 |
| 5/64 | 0.080 | 1.14 | 5.55 |
| — | 0.100 | 1.42 | 6.93 |
| 1/8 | 0.125 | 1.77 | 8.67 |
| 3/16 | 0.188 | 2.67 | 13.04 |
| 1/4 | 0.250 | 3.55 | 17.34 |
| 5/16 | 0.312 | 4.44 | 21.67 |
Where aluminium diamond plate is used
- Trucks and trailers: floors, fenders, headboards, running boards, toolboxes, rear steps and refrigerated-body floors
- Marine: boat decks, gangways, ship stairs and hatch covers in 5052 or 5086
- Industrial access: platforms, stair treads, mezzanine floors, ramps and loading docks, usually in 6061-T6 or 5052
- Buildings: wall protection, corner guards, kick plates, lift and service-area linings, threshold and transition strips
- Transport: bus and rail vehicle floors and step wells, ambulance interiors
- Tanks and tankers: walkways and top surfaces on road tankers and storage tanks
- Retail and décor: display fixtures, garage walls, bar fronts and themed interiors in bright or anodised finish
Cutting, bending and welding diamond plate
Diamond plate cuts with the same tools as other aluminium: shears and saws for straight cuts, and laser, plasma or waterjet for profiles. Bend with the pattern on the outside of the bend where possible, and allow larger bend radii for 5052 and especially 6061-T6 than for 3003. Pattern lugs on the inside of a tight bend can crush or mark the press brake tooling, so use protective film or urethane pads for bright plate.
All common tread plate alloys can be MIG or TIG welded. Use ER5356 filler for 5xxx alloys and either ER4043 or ER5356 for 6061 and 3003, remembering that welding reduces strength near the weld in 6061-T6 and in strain-hardened tempers. Fasten aluminium to steel frames with insulating washers or tape and stainless fasteners to avoid galvanic corrosion.
Aluminium vs steel tread plate
| Factor | Aluminium diamond plate | Steel tread plate |
|---|---|---|
| Weight | About one third of steel | Heavy |
| Corrosion | No rust; no painting needed | Needs galvanising or paint, rusts at damage |
| Appearance | Bright or anodised finishes available | Usually painted or galvanised |
| Strength for same thickness | Lower; use thicker plate or 6061-T6 | Higher |
| Sparking | Low spark risk compared with steel | Can spark on impact |
| Cost per sheet | Higher | Lower |
How to order aluminium diamond plate
- Choose alloy and temperFor example 3003-H22 bright, 5052-H32 mill finish or 6061-T6.
- Specify size and patternBase thickness, sheet size or cutting list, and pattern (diamond, 3-bar, 5-bar).
- Finish and protectionBright, mill, anodised colour; with or without protective film.
- Standards and documentsASTM B632, EN 1386 or ASTM B209 as required; mill test certificate to EN 10204 3.1.
- Packing and deliveryWooden cases or pallets with interleaving; EXW, FOB, CIF or DAP terms.
References and standards
- ASTM B632 – Standard Specification for Aluminum-Alloy Rolled Tread Plate
- EN 1386 – Aluminium and aluminium alloys: tread plate, specifications
- ASTM B209 – Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate
- The Aluminum Association – Aluminum Standards and Data
Aluminium (aluminum) diamond plate: FAQ
What is the difference between diamond plate, tread plate and checker plate?
They are names for the same family of patterned sheet. "Diamond plate" usually refers to the raised-diamond pattern common in North America; "tread plate" and "chequer plate" are broader terms that also cover 3-bar and 5-bar patterns.
Which aluminium diamond plate is the strongest?
6061-T6 is the strongest of the common grades and is used for ramps, platforms and floors that span between supports. 5052-H32 is next and is preferred for marine use; 3003-H22 is softer and mainly decorative or light-duty.
Is aluminium diamond plate good for boats?
Yes, in 5052 or 5086, which resist saltwater well and weld easily. Bright 3003 is less suitable for constant seawater exposure.
How is diamond plate thickness measured?
Nominal thickness refers to the base sheet, not including the height of the raised pattern. Measure away from the lugs or check the mill certificate.
Can aluminium diamond plate be bent?
3003 bends easily; 5052 needs slightly larger radii; 6061-T6 should be bent only over generous radii or it may crack. Bend with the pattern on the outside where possible.
What sizes of aluminum diamond plate are available?
Common sheets are 4 × 8 ft, 4 × 10 ft and 5 × 10 ft, with metric 1250 × 2500 and 1500 × 3000 mm sizes, from about 1.2 to 8 mm thick. Sheets can also be cut to size or supplied in coil.
Looking for aluminium diamond plate?
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