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B-Type vs I-Type aluminium profiles: Slot sizes, anodizing, and accessory compatibility
A practical guide to B-type vs I-type T-slot aluminium profiles: How slot sizes differ, what anodizing means, and which fasteners and accessories are compatible.
How profile names are built: 40x80L I-Type slot 8
Our standard aluminium slot profile names follow a clear logic. Each part of the name describes the profile’s size, geometry, or compatibility. Let’s break down 40x40L I-Type slot 8 step by step:
- 40x80 – The profile measures 40 mm by 80 mm in cross-section.
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L – this optional parameter indicates the wall thickness and therefore the weight and strength of the profile:
- UL – ultra-light version: very thin walls, lowest weight, for non-load-bearing applications.
- L – light version: thinner walls, lower weight, more cost-efficient.
- Missing – standard version: balanced strength and weight.
- S – heavy version, maximum wall thickness and strength.
- I-Type – System type: determines slot geometry and accessory compatibility.
- Slot 8 – the groove is ~8 mm wide, so only slot-8 nuts and connectors will fit. But also the system-type has to be correct
✅ In short: 40x80L I-Type slot 8 means a 40x80 mm aluminium profile, light version, I-Type system, with a ~8 mm slot width.
What are B-type and I-type profiles?
Both are modular T-slot aluminium profile systems. The key difference is slot geometry: the profile cross-section, slot width, and chamfers vary slightly between B-type and I-type series. Those small differences affect which T-nuts, connectors, and panel accessories will fit.
Accessories Compatibility
Every aluminium profile system relies on the right slot size and system type (B-Type or I-Type) to ensure accessories fit correctly. Connectors, brackets, hinges, and T-nuts are precisely designed for their matching slot geometry.
- Slot width (e.g. 6, 8, 10 mm) must match the T-nuts and fasteners you use.
- System type (B-Type or I-Type) defines the profile’s slot shape and therefore the compatible accessory range.
- Mixing systems is possible, but you have to know what you are doing. As a beginner it's recommended to stick to one slot width/system combination
✅ Tip: Always choose accessories specified for your profile’s system type and slot size to guarantee a secure and stable connection.
Anodizing vs. Unanodized Profiles
If not stated differently our profiles are delivered in a clear anodized finish. This has some advantages over an unanodized finish.
| Feature | Anodized | Unanodized |
|---|---|---|
| Appearance | Uniform matte metallic finish | Brighter, less even, extrusion marks visible |
| Protection | Corrosion- and scratch-resistant | Prone to oxidation and scratches |
| Durability | Hard, long-lasting surface | Softer surface, wears faster |
General information
Here you can find general information about our aluminium profiles to DIN EN 12020-1| Aluminium extrusion profiles to DIN EN 12020-1 | |
|---|---|
| Alloy | Principally Al Mg 0.7 Si |
| Material number to DIN EN 573 | Principally EN AW-6063 |
| Material | Principally No. 3.3206 (warm cured) |
| Mechanical specification (value in direction of the extrusion) | |
| Specified tensile strength | Principally Rm = min. 240 N/mm2 |
| Elastic limit | Principally Rp0.2 = min. 190 N/mm2 |
| Breaking elongation | Principally A5 = min. 8% |
| Elasticity | E ≈ 70,000 N/mm2 |
| Brinell hardness | Principally HB ≈ 75 HB |
| Coefficient of linear expansion | a = 23.8 × 10−6 / K |
| Surface to DIN 17611 | E6/EV1 matt pickling and natural-coloured anodized |
| Coat thickness | Min. 10 µm |
| Coat hardness | Principally 250–350 HV |
| Tolerance to | DIN EN 12020-2 |
| Tolerance of the profile cut | ± 0.3 mm |
FAQ Recap
How are profile names built?
A profile name like 40x80L I-Type slot 8 tells you the cross-section (40×80 mm), the wall thickness class (UL, L, Standard, or S), the system type (I-Type or B-Type), and the slot width (e.g. 8 mm).
What is the difference between B-Type and I-Type profiles?
Both are modular slot profile systems, but their slot geometry differs. This affects which nuts, connectors, and accessories fit. Mixing them is not recommended.
Which accessories are compatible with my profile?
Accessories must match both the system type (B-Type or I-Type) and the slot width (6, 8, 10 mm). As a beginner, stick to one system and slot size.
What’s the difference between anodized and unanodized profiles?
Anodized profiles have a uniform matte finish, resist scratches, and offer corrosion protection. Unanodized profiles are brighter but less even, show extrusion marks, and oxidize more easily.
Ready to build?
Choose a series, match the slot size, and grab the right accessories.
