5052と6061のアルミニウム：加工部品にはどちらの合金が適しているか？

In the 5052 vs 6061 aluminum decision, the part’s main process usually settles it. Choose 6061 for CNC machined parts: it is stronger in the T6 temper, cuts cleanly, and anodizes evenly. Choose 5052 for bent sheet metal and parts exposed to salt water, because it forms tightly without cracking and resists marine corrosion better.

簡単な答え： 6061-T6 has higher tensile and yield strength, better machinability, and a more uniform anodized finish. 5052-H32 bends and welds more easily and holds up better in salt water, but it is gummy to machine. If the part is milled from a block, use 6061. If it is folded from sheet, use 5052.

What Is the Difference Between 5052 and 6061?

The difference starts with chemistry. According to the Aluminum Association’s alloy guide, 5xxx alloys use magnesium as the main alloying element, while 6xxx alloys combine magnesium and silicon to form magnesium silicide.

That one change decides how each alloy gets its strength:

• 5052 is non-heat-treatable. It is strengthened by cold working, shown by an “H” temper such as H32 (strain-hardened and stabilized).
• 6061 is heat-treatable. It is solution heat-treated and artificially aged to reach the “T6” temper. Plate for machining often comes as T651, which is T6 stress-relieved by stretching.

Everything else in this comparison, from machinability to welding, follows from that split.

5052 vs 6061 Properties Compared

The table below shows typical values for the tempers engineers use most. Specification minimums in ASTM B209 for sheet and plate are lower, so design to the minimums, not the typical values.

Property (typical)	5052-H32	6061-T6	Better for
極限引張強さ	228 MPa (33 ksi)	310 MPa (45 ksi)	6061
降伏強度	193 MPa (28 ksi)	276 MPa (40 ksi)	6061
Fatigue strength	117 MPa (17 ksi)	96.5 MPa (14 ksi)	5052
Modulus of elasticity	70.3 GPa	68.9 GPa	Similar
密度	2.68 g/cm³	2.70 g/cm³	Similar
熱伝導率	138 W/m·K	167 W/m·K	6061
Heat treatable	いいえ	はい	6061
加工性	Fair, gummy	グッド	6061
Formability and bending	素晴らしい	Poor in T6	5052
溶接性	素晴らしい	Good, loses strength near the weld	5052
Salt water corrosion resistance	素晴らしい	グッド	5052
Cosmetic anodizing	Good, can look less uniform	Very good, even color	6061

Two numbers in the 5052 vs 6061 comparison surprise people. 5052 has the higher fatigue strength, so it handles vibration well. And 6061 moves heat about 20% better, which matters for heat sinks and electronics housings.

Which Is Easier to Machine, 5052 or 6061?

6061 is easier to machine, and by a clear margin.

5052 is soft and ductile. On a mill it tends to smear, form long stringy chips, and weld itself to the tool. That leads to torn surfaces, burrs, and tool wear. It can be machined well. If a design calls for machined features in 5052-H32 aluminum, such as pockets in a formed cover, these habits help:

• Use sharp, polished carbide tools made for aluminum. A dull or coated edge makes the smearing worse.
• Clear chips aggressively with air blast or flood coolant, so stringy chips are not recut.
• Plan a deburring step. 5052 leaves heavier burrs than 6061, so budget for edge finishing on every machined feature.
• Hold tolerances loosely where you can. A soft material moves more under clamping pressure, so very tight flatness is harder to hold.

6061-T6 aluminum is harder, so chips break cleanly and the surface finish comes straight off the tool. That is why it is the default alloy for CNCフライス加工 housings, brackets, and fixtures, and why most shops quote it faster and cheaper per part.

Our position: if a part is mostly machined, specify 6061-T651 plate. Using 5052 for a heavily machined part usually costs more in cycle time and deburring than it saves in material.

Bending and Forming: Where 5052 Wins

5052-H32 aluminum is the standard alloy for bent aluminum sheet metal. It takes tight bend radii without cracking, which makes it ideal for enclosures, brackets, chassis, and covers.

6061-T6 is a poor choice for bending. It tends to crack along the outside of a tight bend. If a 6061 part must be formed, it is usually bent in a softer temper and heat-treated afterward, which adds cost and a distortion risk.

A common mistake is copying the alloy from a machined part onto a sheet metal drawing. If your 金属の曲げ加工 supplier asks to switch a formed part from 6061 to 5052, that is usually the right call.

Corrosion Resistance and Welding

5052 is often called marine grade aluminum. Its magnesium content gives excellent resistance to salt water and salt spray, which is why it is used for boat parts, fuel tanks, and outdoor cabinets.

6061 also resists corrosion well in normal atmospheres, and anodizing improves it further. In constant salt water exposure, 5052 is the safer choice.

For welding, 5052 has the edge. Because it is not heat-treated, the area near the weld keeps much of its strength. 6061-T6 aluminum welds well, usually with 4043 or 5356 filler wire, but the heat destroys the T6 temper in the heat-affected zone next to the weld, so a welded 6061 frame is weaker at the joints unless it is heat-treated again.

How Do the Two Alloys Look After Anodizing?

Both 5052 and 6061 anodize, and both work with II型陽極酸化処理. The difference is appearance.

6061 gives an even, consistent color, which is why it is the usual choice for cosmetic parts. 5052 can come out slightly less uniform, and it may show a different shade from 6061 even in the same tank.

It also matters for aluminum sheet metal parts that sit next to machined parts, and that is where many assemblies go wrong.

Mixing Both Alloys in One Assembly

Plenty of products use both alloys, and this is where the 5052 or 6061 question gets less clear-cut. A classic case: an enclosure with a machined 6061 base and a bent 5052 lid.

It works, but two problems come up often:

1. Color mismatch after anodizing. Black or colored anodize on 5052 and 6061 rarely matches perfectly. If the parts sit side by side, ask for color samples of both alloys before production, or specify an acceptable color range.
2. Different suppliers, different tanks. When the sheet metal part and the machined part are anodized by different shops, the mismatch gets worse. Keep finishing for both parts with one supplier where possible.

Neither problem is a reason to avoid mixing alloys. Just plan for it on the drawing.

How to Call Out the Alloy on a Drawing

“Aluminum” on a drawing is not a specification, whether you pick 5052 or 6061. Write the alloy, temper, and product form:

• Machined parts: “Aluminum 6061-T651 plate” or “6061-T6511 bar,” depending on the stock.
• Sheet metal parts: “Aluminum 5052-H32 sheet,” plus thickness.
• Standard: add the governing specification, such as ASTM B209 for sheet and plate, if your customer or industry requires it.
• Finish: state anodize type, class, and color, and whether dimensions apply before or after finishing.

Ask for a mill test certificate with each batch. It confirms the alloy and temper you received match the drawing.

Which Alloy Should You Choose for Your Part?

Your part	Best choice	なぜ
Milled housing, bracket, or fixture	6061-T651	Strength, clean machining, even anodizing
Bent enclosure, cover, or chassis	5052-H32	Tight bends without cracking
Marine or salt spray exposure	5052	Better salt water corrosion resistance
Welded frame that must stay strong	5052, or 6061 re-heat-treated	5052 keeps more strength at the weld
Heat sink or thermal plate	6061	Higher thermal conductivity
Vibration-loaded thin part	5052	Higher fatigue strength

When a part is both machined and bent, settle 5052 vs 6061 by the dominant process and design around the weaker property.

よくある質問

Is 5052 stronger than 6061?

No. 6061-T6 has higher tensile and yield strength than 5052-H32, with typical yield strength around 276 MPa compared with 193 MPa. However, 5052 has higher fatigue strength and keeps more of its strength after welding, so in some vibration-loaded or welded parts it can perform better overall.

Can 5052 aluminum be CNC machined?

Yes, but it is harder to machine well than 6061. 5052 is soft and gummy, so it forms stringy chips and built-up edge on the tool. Sharp tools, good chip evacuation, and conservative cutting parameters help. For heavily machined parts, 6061-T651 is usually faster and cheaper per part.

Can you bend 6061 aluminum?

You can, but 6061-T6 often cracks on tight bends. Use a generous bend radius, or form the part in a softer temper and heat-treat it afterward. For bent sheet metal parts, 5052-H32 is usually the better choice because it forms tight radii without cracking.

Which is better for marine use, 5052 or 6061?

5052 is generally better for marine use. Its magnesium content gives excellent resistance to salt water and salt spray, which is why it is called marine grade aluminum. 6061 also performs well outdoors, especially when anodized, and is chosen when the part needs higher strength.

Is 5052 cheaper than 6061?

Raw material prices are usually close and depend on form and market conditions. The bigger cost difference comes from processing. 5052 is cheaper to bend and weld, while 6061 is cheaper to machine. Compare the finished part price, not the price per kilogram of stock.

Choosing Between 5052 vs 6061 Aluminum for Your Next Part

For the 5052 vs 6061 aluminum choice, start with the process. Machined parts belong in 6061, bent sheet parts in 5052, and marine or welded assemblies lean toward 5052.

Tuowei Precision works with both alloys, including 6061-T651 plate for machined parts and 5052 sheet for formed parts. Send your drawing through the Tuowei Precisionのホームページ for a DFM (design for manufacturing) review, and our engineers will flag alloy or temper changes before cutting starts.