Metal Extrusion Services

Extrusion Types and Profiles

KH-TAT collaborates with leading extrusion suppliers, utilizing advanced technology to provide high-quality extruded parts. Leveraging our manufacturing network, we support a wide variety of metal extrusion types and profiles.

Direct Extrusion:Direct extrusion (also known as forward extrusion) is the most common metal extrusion method. The billet is pushed into a container under high pressure by a piston, and the material flows in the direction of piston movement, being extruded from the opening of a fixed die. Compared to indirect extrusion, direct extrusion can achieve larger profile sizes and higher surface finishes.

The disadvantage is the greater friction between the material and the container wall, leading to reduced die pressure and temperature fluctuations, making dimensional consistency and material property control more challenging.

Indirect Extrusion:In indirect extrusion, the material is placed in and fixed in a container, and a hollow piston moves above the material, forcing it through the die opening. Also known as reverse extrusion, because the material flow direction is opposite to the piston movement. There is no relative movement between the material and the container, significantly reducing friction and energy consumption and heat generation. Compared to direct extrusion, it generates less heat and offers better dimensional consistency, material properties, and grain size control.

The disadvantage is the limited overall die size, as it must be housed within a hollow punch. Impurities on the billet surface may enter the extruded product, affecting surface finish and aesthetics.

Hot Extrusion, Warm Extrusion, and Cold Extrusion

Extrusion temperature, relative to room temperature and the material's recrystallization temperature, determines the extrusion method:

• Hot Extrusion: The billet is heated above the material's recrystallization temperature, typically associated with direct extrusion. Heating softens the material, preventing work hardening, facilitating flow through the die, and reducing die wear.
• Warm Extrusion: The material is heated above room temperature but well below the recrystallization temperature.
• Cold Extrusion: The material is not heated and remains at room temperature.

Cold and warm extrusion can improve product hardness and strength, and are best suited for highly ductile materials such as aluminum; they are typical examples of indirect extrusion. However, overheating should be avoided as it exacerbates die wear and shortens its lifespan; therefore, most manufacturers choose hot extrusion.

Extruded profiles refer to the cross-sectional shape that constitutes an extruded product. KH-TAT's custom manufacturing service can produce parts using custom extruded profiles, and can also perform post-processing on existing aluminum extruded profiles to save costs and time. Common existing profiles include:

• T-slot aluminum extruded profiles
• Aluminum angles
• T-beams, H-beams, Z-beams
• I-beams
• U-slots
• Cap-shaped slots
• Rectangular tubes
• Round tubes and pipes

Aluminum Profiles

Extruded aluminum profiles account for approximately 80% of all extruded metal products. Due to their wide range of applications, excellent mechanical properties, rich surface treatment options, and high ductility, they are ideal materials for extrusion processes. Most extruded aluminum alloys are lightweight, corrosion-resistant, and possess high thermal and electrical conductivity; each alloy has unique characteristics. Commonly used alloys include 6061 and 6063. For stainless steel or other metal extruded profiles, the quotation interface offers a "Custom Material" option; please submit your requirements.

Extruded Parts Surface Finish Options

• Extruded State: The surface remains as it was after extrusion, without any subsequent treatment. Surface roughness varies depending on the alloy and grain structure, typically ranging from 64 μin to 125 μin Ra. Noticeable grain lines or discoloration streaks may be present.
• Anodizing (Type II or Type III): Type II anodizing forms a corrosion-resistant oxide layer that can be dyed in transparent, black, red, gold, etc. Type III anodizing produces a thicker layer with both corrosion and wear resistance. Anodized coatings are non-conductive.
• Powder Coating: Powder coating is electrostatically sprayed and then baked to cure, forming a more robust, wear-resistant, and corrosion-resistant durable coating than traditional wet spraying. A variety of colors and textures are available to meet visual requirements.
• Wet Spraying: All extruded metal parts can be coated with paints of various formulations and colors. For more information... For color matching, please specify the paint brand and part number on the drawings or specifications.
• Electroplating: Extruded parts can be electroless plated with nickel, brass, tin, chromium, chromates, Teflon, silver, and gold.
• Chemical Film: Chromate conversion coatings protect aluminum from corrosion, improve paint and primer adhesion, and maintain the metal's conductivity.
• Tumbling: Parts are tumbled using a vibrating medium to remove sharp edges and smooth the surface. Suitable for small parts that can be placed in a tumbling machine.
• Custom Surface Treatments: If the desired surface treatment is not found, please select "Custom" on the quotation page and inform us of your requirements. We will explore more options for you.
   

Advantages

Dimensional Accuracy and Stability: Modern extrusion presses and processes produce extruded profiles with small tolerances, durability, and dimensional stability, suitable for both brittle and ductile materials.
Low Part Costs: Through careful design, extruded frames and shells eliminate multiple assembly steps, easily achieving high-volume and cost-effective production.
Low Die Costs: The extrusion process is relatively simple, and die costs are 80-90% lower than other processes such as injection molding or die casting.
High Part Complexity: Extrusion molding is ideal for manufacturing parts with complex cross-sectional shapes, including features such as undercuts, T-slots, and grooves.

Disadvantages

Initial Setup Costs: In addition to the unit price of the extruded part, die and tooling manufacturing incur additional costs, reflected in tooling and setup fees.
Design Limitations: The cross-section of the extruded part must remain constant, limiting design freedom. Features such as countersunk holes, grooves, or bosses cannot be extruded and require additional post-processing.
Delivery Cycle: The number of extrusion molding manufacturers is relatively small, and die production and iteration cycles can take several months. As a result, the delivery cycle for the first batch of parts is typically four to six weeks.