Pick the profile for stiffness
Size beams from the maker's Ix and Iy values and a deflection limit, commonly L/500 to L/1000 for machine frames.
Modular framing extrusions
T-Slot Aluminium Framing Profiles
T-slot aluminium profiles are extruded framing sections with undercut grooves on each face, so frames can be bolted together with T-nuts and brackets instead of welding. They are a system: profile series, slot size, fasteners and connectors must all match. Metline supplies T-slot profiles in metric and imperial series, cut to length and machined for connectors, with accessories, to customers worldwide.
- Alloy
- 6063-T5/T6, 6061-T6
- Metric series
- 20, 30, 40, 45, 50, 60, 80
- Imperial series
- 10 (1 in), 15 (1.5 in)
- Finish
- Clear anodised, black anodised
What are T-slot aluminium profiles?
A T-slot profile is a hollow or semi-hollow extrusion, usually square or rectangular in outline, with a T-shaped groove running the full length of one or more faces. Fasteners slide or drop into the groove and clamp brackets, panels or other profiles anywhere along it. The result is a structure that can be designed in hours, assembled with hand tools, and later moved, extended or rebuilt.
Because joints are bolted, there is no welding distortion, no painting after assembly and no heat damage to the anodised finish. That makes T-slot framing the default choice for machine guards, workbenches, automation cells, test rigs, cleanroom equipment, displays and many custom structures. For long production runs of a single frame, a welded or dedicated extrusion may cost less; for anything that changes, T-slot usually wins.
The key point for buyers is compatibility. Profiles from different makers can share an outside size but differ in slot opening, groove depth, wall layout and core hole, so their nuts and connectors may not fit each other. Always name the system and profile reference, or send a cross-section drawing.
T-slot series, slot sizes and typical weights
The table shows common industry conventions. Exact slot dimensions, section properties and weights vary by maker and profile, so treat these as guides and confirm against the system drawing.
| Series | Common profiles | Typical slot opening | Typical weight (standard profile) | Typical uses |
|---|---|---|---|---|
| 20 mm | 20 × 20, 20 × 40, 20 × 60, 20 × 80 | 6 mm | about 0.4 – 0.5 kg/m (20 × 20) | 3D printers, small rigs, enclosures, displays |
| 30 mm | 30 × 30, 30 × 60 | 8 mm | about 0.8 – 0.9 kg/m (30 × 30) | Light guards, workstations, fixtures |
| 40 mm | 40 × 40, 40 × 80, 80 × 80 | 8 or 10 mm | about 1.3 – 1.7 kg/m (40 × 40) | Machine frames, guarding, conveyors, benches |
| 45 mm | 45 × 45, 45 × 90, 90 × 90 | 10 mm | about 1.7 – 2.2 kg/m (45 × 45) | Heavier machine bases, gantries, automation |
| 50 / 60 mm | 50 × 50, 60 × 60 | 10 – 12 mm | about 2 – 3 kg/m | Heavy frames, linear-motion bases |
| 80 mm and up | 80 × 80, 80 × 160, 90 × 180 | 10 or 14 mm | about 4 – 10 kg/m | Load-bearing structures, gantry beams |
| 10 series (imperial) | 1010, 1020, 1030, 1515 equivalents | about 0.256 in (6.5 mm) | about 0.5 lb/ft (1010) | North American framing |
| 15 series (imperial) | 1515, 1530, 3030 | about 0.320 in (8.1 mm) | about 1.0 lb/ft (1515) | North American machine frames |
Light, standard and heavy versions of the same outside size differ in wall thickness, so weight and stiffness can vary by 50 % or more. Use the maker's section properties (area, Ix, Iy, Wx, Wy) for load calculations.
Alloy, temper and mechanical properties
T-slot profiles are almost always extruded from 6063 or the similar European grade 6060, aged to T5 or T6. These alloys flow easily through complex dies, give sharp slot detail and produce a smooth surface that anodises evenly. Where higher strength is needed, 6061-T6 or 6005A-T6 is used for heavy profiles.
| Grade and temper | Minimum tensile | Minimum yield (0.2 %) | Notes |
|---|---|---|---|
| 6063-T5 (EN 755-2, t ≤ 12.5 mm) | 150 MPa | 110 MPa | Common for standard profiles |
| 6063-T6 (EN 755-2, t ≤ 3 mm) | 205 MPa | 170 MPa | Higher strength for light profiles |
| 6063-T66 (EN 755-2) | about 245 MPa | about 200 MPa | Enhanced temper used by some systems |
| 6005A-T6 (EN 755-2, t ≤ 5 mm) | 255 – 270 MPa | 215 – 225 MPa | Heavy structural profiles |
| 6061-T6 (ASTM B221) | 260 MPa | 240 MPa | North American heavy profiles |
Physical properties (6063-T5/T6, typical)
- Density
- 2.70 g/cm³
- Modulus of elasticity
- about 69 GPa
- Thermal expansion
- about 23 µm/m·°C
- Thermal conductivity
- about 200 W/m·K
- Anodic coating
- Typically 10 – 15 µm clear or black anodising
Designing a T-slot frame: stiffness, deflection and joints
T-slot frames are usually limited by deflection, not by strength. Aluminium has about one third of the stiffness of steel, so a beam that is strong enough may still sag or vibrate too much. Deflection of a simply supported beam under a central load is F·L³ / (48·E·I): doubling the span increases deflection eightfold, while switching from a 40 × 40 to a 40 × 80 profile on edge raises the moment of inertia roughly five- to sixfold.
Choose joints by load
Angle brackets are quick and adjustable; internal anchor or end connectors give clean, stiff joints; gusset plates carry the highest moments.
Add bracing
Diagonal braces or panels turn a flexible rectangle into a rigid frame, often more effectively than a heavier profile.
Mind the fastener
Slot nuts carry a rated pull-out load; heavy or vibrating loads need more nuts, longer brackets or through-bolting.
Allow for vibration
Dynamic machines may need heavier profiles, filled cores or damping feet to avoid resonance.
Plan cable and air routing
Core holes and slot covers can carry cables and compressed air neatly inside the frame.
Fasteners and accessories that complete the system
| Component | Purpose | Points to check |
|---|---|---|
| T-nuts / slot nuts | Clamp brackets and panels in the slot | Slot size, thread, slide-in or drop-in (rotating) type, spring-loaded to hold position |
| Angle brackets | Connect profiles at 90° and other angles | Bracket size relative to profile, number of bolts per leg, cast or extruded |
| Anchor and end connectors | Hidden joints through tapped ends or access holes | Require end tapping or a drilled access hole on the profile |
| End caps and slot covers | Finish ends, keep dirt out of slots | Colour and slot size |
| Panels and panel holders | Guarding with polycarbonate, acrylic, mesh or composite | Panel thickness and seal profile |
| Hinges, handles, feet, castors | Doors, mobility and levelling | Load rating and mounting thread |
| Linear bearings | Sliding carriages that run on the profile | Profile tolerance and surface condition |
Tolerances, machining and finish
Precision T-slot profiles are typically extruded to tighter-than-standard tolerances for outside size, twist and straightness, because linear guides and square frames depend on them. EN 12020-2 (precision 6060/6063 profiles) and EN 755-9 (general profiles) give the reference limits; system makers often hold tighter internal values for straightness and twist per metre.
- Cutting: saw cut to length, commonly within ±0.2 – 0.5 mm, with square ends for butt joints
- End machining: tapping of the core hole, counterbores for anchor fasteners, access holes for connectors
- Anodising: clear (natural) or black anodising gives corrosion and wear resistance and a consistent appearance
- Inspection: dimensional check of profile, length and squareness; EN 10204 3.1 material certificate on request
Where T-slot aluminium framing is used
- Machine building: machine frames, guarding, safety fencing and enclosures
- Automation: robot cells, pick-and-place gantries, linear-motion systems and conveyor frames
- Workplace: lean workstations, assembly benches, carts and material racks
- Laboratories and cleanrooms: test rigs, optical tables, laminar-flow hood frames
- 3D printing and CNC: printer frames, router gantries and small machine bases
- Retail and events: displays, exhibition stands and signage frames
- Renewables and electronics: test fixtures, server racks and solar test structures
How to order T-slot profiles from Metline
- SpecifyProfile series and reference (or a cross-section drawing), cut list with lengths and quantities, end machining, finish, and the fasteners and accessories required.
- QuoteWe confirm alloy, temper, tolerances, certification, packing and delivery terms (EXW, FOB, CIF or DAP) for your destination.
- ProcessProfiles are cut, end-machined and checked against the cut list; fasteners and accessories are kitted to the frame where requested.
- DocumentDeliveries include a packing list by cut length; an EN 10204 3.1 material certificate is available on request.
- ShipProfiles are wrapped or sleeved to protect the anodised finish, boxed or crated with accessories, and shipped by sea, air or courier.
References and standards
- EN 755-2 – Extruded rod/bar, tube and profiles: mechanical properties
- EN 12020-2 – Extruded precision profiles in alloys EN AW-6060 and EN AW-6063: tolerances
- ASTM B221 – Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets)
- T-slot structural framing – overview of series and systems
T-slot aluminium (aluminum) profiles: frequently asked questions
Are T-slot profiles from different brands compatible?
Not reliably. Two profiles with the same outside size can have different slot openings, groove depths and core holes, so nuts and connectors may not fit. Stay within one system, or confirm the cross-section before mixing parts.
What alloy are T-slot profiles made from?
Usually 6063 or 6060 in T5 or T6 temper, which extrudes sharp slot detail and anodises well. Heavy profiles may use 6061-T6 or 6005A-T6 for extra strength.
What slot size goes with a 40 × 40 profile?
Most 40 mm systems use an 8 mm slot; some use 10 mm. Check the profile drawing before ordering nuts, bolts and brackets.
How do I choose the right profile size for my frame?
Start from the load and the allowable deflection, then use the maker's moment of inertia to calculate sag. In most frames, stiffness rather than strength decides the size. Bracing and deeper profiles (40 × 80 instead of 40 × 40) are the most efficient ways to stiffen a frame.
Can T-slot profiles be cut and machined to length?
Yes. Profiles are supplied in full lengths or cut to a cut list, with end tapping, counterbores and access holes for hidden connectors.
Is anodising necessary on T-slot extrusions?
It is standard because it protects the surface, resists wear from sliding nuts and gives a uniform look. Mill-finish profiles are cheaper but mark and oxidise more easily.
Building a T-slot frame?
Send your profile series, cut list or drawing and quantity. We will reply with matching profiles, fasteners and a delivered price.
