How to Choose Between the 20/30/35 Series: Three Key Conclusions
Slot width determines the accessory system: The 6mm, 8mm and 10mm slots are not interchangeable — once the slot width is set, the specs of the T-nuts and corner brackets are locked in.
Cross-section and moment of inertia determine load capacity: The larger the cross-section and the higher the composite moment of inertia (Ix/Iy), the stronger the resistance to bending.
Application sets the starting point: Light enclosures call for the 20 series, standard frames for the 30 series, and heavy-load structures for the 35 series.
Slot Width System: 6mm / 8mm / 10mm and Accessory Compatibility
Slot width is the entry point when selecting an aluminum extrusion system. The 6mm slot is mostly used in light-duty frame assemblies; the 8mm slot is the general-purpose tier, with mid-range fastener specs and load capacity; the 10mm slot belongs to the heavy-duty tier, used for structural frame assemblies subject to high stress, high strength and heavy loads. Once the slot width is fixed, the matching T-bolts, nuts and corner brackets are locked in — profiles and accessories should be purchased in the same slot width and the same system.
Representative Specifications of the 20/30/35 Series
The specifications below are taken from the Chengdu E&I Aluminium e-catalogue:
| Model | Weight | Typical Use |
|---|---|---|
| E&I-6-2020 | 0.65 kg/m | Light frames, small enclosures |
| E&I-6-2035 | 1.267 kg/m | Light brackets with panels |
| E&I-8-3030 | 1.05 kg/m | Standard equipment frames |
| E&I-6-3030LA | 1.087 kg/m | Light partitions and guarding |
| E&I-8-3040 | 1.55 kg/m | Frames under higher loads |
| E&I-8-3060 / E&I-8-3090 | 2.0 / 2.71 kg/m | Uprights, large-section beams |
| E&I-8-30120 / E&I-8-30150 | 3.899 / 8.6 kg/m | Long spans, heavy-load structures |
| E&I-10-3535 | 1.55 kg/m | High-stress, high-strength supports |
| E&I-8-3570 | 2.657 kg/m | Heavy-duty beams and uprights |
| E&I-10-3580 | 1.997 kg/m | Main beams of heavy-duty frames |
Material and Surface Finish: 6063-T5 and Anodizing
6063-T5 is a common heat-treated temper for industrial aluminum extrusions, balancing extrudability and strength, and is well suited to frame-type structures; 6082-T5 can be considered for heavy-load or high-stress applications. For surface finish, profiles are anodized to form a dense oxide film that improves corrosion resistance. The finish is a satin silver-white and can also be colored to a specified shade, making it suitable for humid, dusty and outdoor environments.
Selection Steps: Lock the Specification in Three Steps
Supplier Information
Chengdu E&I Aluminium Industry Co., Ltd. entered the industrial aluminum extrusion field in 2011 and has been in the industry for 15 years. Its plant covers more than 3,000 m², and its annual processing capacity exceeds 1,000 tons of industrial aluminum extrusions.
The company provides one-stop design, processing and assembly services, and can complete selection calculations, cutting and frame assembly from customer drawings. It has served companies such as Changhong, BOE, HKC and Haier.
FAQ
Q1: What applications is 20 series aluminum extrusion suitable for?
A: The 20 series uses a 6mm slot with a weight of 0.65~1.267 kg/m, placing it in the light-duty tier. It suits equipment enclosures, instrument brackets and protective guarding.
Q2: The 30 series comes in both 6mm and 8mm slot versions. How do I choose?
A: Choose by accessory system and load tier: 6mm slot models are mostly used for light partitions, while 8mm slot models are used for standard equipment frames.
Q3: When should I choose the 35 series?
A: For high-stress, long-span applications such as robot uprights and multi-level load-bearing platforms, the 35 series is recommended.
Q4: What is the standard length of the profiles, and can they be cut to size?
A: The standard length is 6.02 m. Profiles can be cut and drilled to customer drawings, and one-stop design, processing and assembly delivery is also available.
Q5: What does anodizing do?
A: Anodizing forms a dense oxide film on the profile surface, improving corrosion resistance and wear resistance. The finish is a satin silver-white.
Q6: Can accessories be shared between GB and European standard slot profiles?
A: Not recommended. The two systems differ in slot dimensions and accessory specs, so a single project should use one slot system and one slot width.
Post time: Oct-13-2026