T-slot profile dimensions
T-slot (profile framing) extrusions are specified by their envelope series — 20, 30, 40, 45 mm — the slot geometry and the centre bore. The table lists representative sizes with weight per metre at 6063 aluminium density, and the tool lets you draw a slotted section, change the size and read back its properties.
| Designation | W×H mm | A mm² | Weight kg/m | Ix mm⁴ | Sx mm³ |
|---|---|---|---|---|---|
| 20×20 T-Slot | 20×20 | 140.2 | 0.38 / 0.20 | 6856 | 686 |
| 40×40 T-Slot | 40×40 | 579.7 | 1.57 / 0.86 | 109828 | 5491 |
Weight column: computed (geometry × density) / published catalogue where known. Section properties integrated exactly from geometry; verify before release.
DXF (LWPOLYLINE/CIRCLE) · CSV/XLSX with X,Y columns (blank row = new loop). DWG → export as DXF first.
EL 69,000 MPa · Aluminium extrusion 6063-T5, clear anodized
| Area | A | 140.2 | mm² |
| Mass / metre | m | 0.378(0.254 lb/ft) | kg/m |
| 2nd moment | Ix | 6856 | mm⁴ |
| 2nd moment | Iy | 6856 | mm⁴ |
| Section mod. | Sx | 685.6 | mm³ |
| Section mod. | Sy | 685.6 | mm³ |
| Gyration | rx | 6.994 | mm |
| Gyration | ry | 6.994 | mm |
| Torsion | J | — | mm⁴ |
| Published catalogue weight: 0.20 kg/m · computed Δ 89% | |||
Derived exactly from the section polygon (Green’s theorem). Fillets excluded (<2% effect). Verify against certified data before release.
How T-slot sizes are named
The number is the face dimension in millimetres: a 2020 profile is 20×20 mm, a 4040 is 40×40 mm. Series also differ by slot width (the throat that accepts the bolt head), typically 6 mm on 20-series and 8–10 mm on 40-series, and by the centre bore used for end-tapping.
Weight and stiffness
A 20×20 profile is roughly 0.2 kg/m and a 40×40 around 0.85 kg/m in 6063 aluminium. The slots remove material from the corners, so a real profile is lighter and slightly less stiff than a solid square of the same envelope — always confirm against the manufacturer's published section data for a load-bearing frame.
Visualising a T-slot section
Dimviz draws a representative T-slot outline — throat, chamber and centre bore — so you can see the envelope and compare series. For an exact brand profile (with its specific rib pattern and moment of inertia), import the die's DXF; that capability is on the roadmap.
FAQ
What are standard T-slot profile sizes?+
The common metric framing series are 20, 30, 40 and 45 mm, in square (20×20, 40×40) and rectangular (20×40, 40×80) envelopes, with matching slot widths and centre bores.
How much does 40×40 T-slot weigh per metre?+
About 0.85 kg/m in 6063 aluminium for a standard single-bore 40×40 profile; heavier for reinforced or multi-bore variants.
What size bolt fits a T-slot?+
Slot width sets the bolt: 20-series (6 mm slot) typically takes M5, 40-series (8 mm slot) M8. Always match the manufacturer's T-nut to the slot.