In industrial procurement, the designation 1100-H112 specifies both the chemical purity and the physical temper of the material. The "1100" indicates a commercially pure aluminum alloy containing a minimum of 99.0% aluminum. The "H112" designates a strain-hardened temper resulting directly from high-temperature shaping processes, such as hot extrusion, without strict mechanical property limits.
In short, the 1100-H112 aluminum pipe represents a high-purity material state offering outstanding corrosion resistance, maximum electrical conductivity, and exceptional formability, though it possesses relatively low mechanical strength.
What is a 1100 Aluminum Tube?
To fully understand the material, we must first break down the 1xxx series alloy. The 1100 grade is the most heavily alloyed of the commercially pure aluminum series, yet it still maintains a minimum of 99.00% aluminum. Because it lacks significant hardening elements like copper, magnesium, or silicon, it cannot be strengthened through heat treatment.
Chemical Composition of 1100 Aluminum Alloy (%)
| Element | Content (%) | Description |
|---|---|---|
| Aluminum (Al) | ≥ 99.00 | Primary element, ensures high conductivity |
| Silicon (Si) | ≤ 0.95 | Impurity element |
| Iron (Fe) | ≤ 0.95 | Impurity element |
| Copper (Cu) | 0.05 – 0.20 | Slightly improves strength |
| Manganese (Mn) | ≤ 0.05 | Trace element |
| Zinc (Zn) | ≤ 0.10 | Impurity control |
| Others (each) | ≤ 0.05 | Residual elements |
| Others (total) | ≤ 0.15 | Total residuals |
What Does H112 Mean for Extruded Pipes?
The temper designation is the most misunderstood factor in aluminum procurement. While the alloy dictates the chemistry, the temper dictates the mechanical behavior.
The letter "H" stands for strain-hardened (cold-worked or hot-worked).
The number "1" means it is strain-hardened only, without any subsequent thermal treatment to soften it.
The number "12" specifically indicates that the pipe has acquired some degree of strain hardening during working at elevated temperatures (such as hot extrusion) but does not have precisely controlled mechanical property limits.
Unlike cold-drawn tubes that are pulled through a die at room temperature to hit an exact hardness limit, the H112 temper is a natural byproduct of the hot extrusion process. The metal is heated, pushed over a mandrel to form a seamless pipe, and allowed to cool. The resulting H112 temper is stable, highly reliable, and guarantees excellent formability.
Mechanical Properties of 1100-H112 Seamless Aluminum Pipe
Engineers need data to calculate bending radii and forming limits. Because H112 does not impose strict minimums in the ASTM B241 standard for this specific alloy, the following are the typical reference values generated during factory testing:
| Property | Typical Value |
| Tensile Strength | 90 - 110 MPa |
| Yield Strength | 35 - 50 MPa |
| Elongation (in 50mm) | 15% - 25% |
| Hardness (Brinell) | 25 - 35 HB |
The critical takeaway here is the yield strength. At roughly 35 MPa, this pipe yields to physical force very easily. This is not a defect; it is a feature. It allows fabricators to execute tight-radius bends, deep flaring, and complex system routing without the metal cracking or springing back.
1100-H112 vs 3003-O and 3003-H14 Aluminum Pipe
When sourcing materials, buyers often encounter different tempers and wonder how they affect fabrication. Let us compare the H112 temper to other common industry states.
1100 H112 vs 3003 O Temper (Annealed):
The "O" temper represents the softest possible state of the metal, achieved by baking the pipe in an annealing furnace to completely remove all internal stresses. While 3003-O or 1100-O pipes are extremely soft, the H112 temper is slightly stronger and holds its dimensional shape better during transport and handling, while still being very easy to form.
1100 H112 vs 3003 H14 Temper (Half-Hard):
You will frequently see the 3003-H14 aluminum pipe in general industrial applications. The "H14" temper means the pipe has been deliberately cold-worked to reach exactly half of its maximum possible hardness. H14 requires precise mechanical rolling or drawing. H112 is strictly a hot-worked state. H14 offers higher rigidity, while H112 offers superior bending capabilities.
Why Seamless Pipes Default to H112
Why is the H112 temper so common when you buy 1100 aluminum seamless tube? The answer lies in the manufacturing physics of thick-walled and seamless pipes.
To create a pipe with no longitudinal weld seam, a solid aluminum billet must be heated to a plastic state and pierced by a heavy-duty hydraulic press. Because the metal is shaped while incredibly hot, it cannot retain the extreme internal stresses associated with cold-working (like H18 full-hard tempers). The natural state the pipe settles into after hot extrusion and stretch-straightening is H112. It is the most economical and physically stable way to produce large-diameter or heavy-wall seamless pipes.
Core Advantages and Limitations of 1100-H112 Aluminum Tubing
Every engineering material has distinct boundaries. Knowing where 1100-H112 excels and where it fails is the foundation of smart procurement.
Advantages:
- Extreme Corrosion Resistance: The lack of heavy alloying elements prevents galvanic pitting, making it safe for low-concentration chemical transfer and food-grade fluid handling.
- Exceptional Ductility: With elongation often exceeding 20%, it can be bent into serpentine coils for refrigeration units without fracturing.
- Weldability: It is highly weldable using standard TIG or MIG processes. ER1100 filler wire is used to ensure the weld seam matches the corrosion resistance of the base pipe.
Limitations:
- Very Low Load Capacity: It cannot be used as a structural support pillar, scaffolding, or a high-pressure pneumatic cylinder.
- Not Heat Treatable: You cannot subject this pipe to a T6 aging process to make it stronger. The strength you buy is the strength it keeps.
Are your current aluminum pipes cracking during the bending process, or are you overpaying for structural alloys in non-structural applications? Incorrect temper selection is a massive drain on manufacturing budgets. Send your project's operating pressure, bending radius, and chemical medium to our technical team for a free material assessment today.
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