Al 7005 and Al 7046 Aluminum Alloy – What’s In the High-End Bicycle Frame Mix?

Al 7005 is the main alloy you’ll find in higher end bicycle frames. An alternative is Al 7046 which is 80% stronger and around 16% lighter. It costs more but not so much more as to make it not cost-effective to use it.

Here’s what goes into these alloys in the various % proportions, what makes for a rather toxic cocktail, considered individually:
7005: Silicon 0.079, Iron 0.105, Copper 0.035, Manganese 0.259, Magnesium 1.143, Zinc 4.09, Nickel , Chromium 0.0053, Lead 0.001, Tin 0.0014, Titanium 0.0238,  Silver 0.001, Boron 0.0013, Beryllium 0.001, Bismuth 0.0063, Calcium 0.0002, Cadmium 0.002, Gallium 0.0133, Sodium 0.001, Phosphorus 0.001, Antimony 0.0045, Stontium 0.001, Lithium 0.0021, Vanadium 0.0102, Zirconium 0.1029, Cobalt 0.001, Aluminium 94.0113

7046: Silicon 0.0699, Iron 0.118, Copper 0.0183, Manganese 0.1348, Magnesium 1.2, Zinc 6.8, Nickel 0.0041, Chromium 0.1256, Lead 0.0013, Tin 0.001, Titanium 0.0224,  Silver 0.001, Boron 0.001, Beryllium 0.001, Bismuth 0.0067,  Calcium 0.0001, Cadmium 0.0016, Gallium 0.0112, Sodium 0.001, Phosphorus 0.001, Antimony 0.0039, Stontium 0.001, Lithium 0.001, Vanadium 0.0116, Zirconium 0.1257, Cobalt 0.001, Aluminium 91.2514.

The main difference here is the proportion of aluminum, some 3% less in al7046 compared with al7005. Other important differences are that 7005 has more copper and manganese, nearly twice as much as 7046. It has 50% more calcium, 40% more tin, 30% more nickel and boron.

7046 has three times the amount of chromium compared with 7005, 40% more zinc, 23% more lead, 18% more zirconium, 13% more vanadium and 11% more iron.

For the consumer who is not into sprint finishes more important numbers might include the 15% extra weight thereabouts of a a 7046 frame compared to the basic monocoque carbon (not the super-cheapies)  frame.

But that’s offset by the several percent of discount in cost over carbon, equal or superior stiffness, and whether or not it will really matter unless you are performing at a level where a few seconds here or there may count.

And that’s 100% of this post.

7 thoughts on “Al 7005 and Al 7046 Aluminum Alloy – What’s In the High-End Bicycle Frame Mix?”

  1. My understanding is that the alloys available in Taiwan are not always the same as those available in the USA; more related to the tolerances of additional metals in the alloy. Is this true? What is the effect?

  2. I don’t know enough about the subject to be able to answer that one Jonathan. Hopefully other readers can help out.

  3. Andrew Kerslake

    I have read that different mills may produce different qualities of tubing, but it would be difficult to blacklist an entire region rather than an individual mill.

  4. In shopping for an aluminum alloy bicycle frame, is there any way of determining the alloy and heat treating process? Could it be marked on the frame or does one have to trust that the vendor is correctly representing the frame he is selling?

  5. No, there’s no way to tell. Some bikes frames will have stickers eg. 7005 T6. Ultimately you have to trust the vendor on this.

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