7068 is far stronger again than 7075 and can be machined very thinly and remain strong. It is very similar to titanium in strength, apparently.
7068 is only about 12% higher in ultimate tensile strength and about 17% higher in tensile yield strength than 7075, nowhere near that of titanium. Also, the price about 25% higher than 7075, at least…
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This is taken directly from the product description for the Sengoku Kenshin:
‘7068 Aluminum is an amazingly strong Aluminum alloy that actually has a better weight/strength ration than grade 5 Titanium! This allows for weight distribution that feels similar to Titanium without the crazy Ti price tag’
It certainly sounds like it’s very near in strength to me.
Taken from Tennalum website.
Strength to weight ratio is not the same thing as ultimate or yield strength of a material. Saying that 7068 allows for weight distribution similar to Titanium is simply ignorant, as weight distribution in a yoyo is driven primarily by the density of the material, very much less by the thickness of the thinnest wall that can be safely executed. 7068 aluminum has a density of 2.85 gm/cc, 7075 is 2.81 gm/cc, an increase of only 1.4%. Titanium has a density of 4.43 gm/cc. Mass distribution in a 7068 yoyo will be essentially what you can get with 7075, albeit with the potential for very slightly thinner walls. Not very much difference, less so than going from 6061 to 7075.
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Thank you for explaining that!
The following excerpt is from the same sight that Rizki got his graph from. It is the paragraph immediately after the graph. It is information I had not read before 10 minutes ago. So I am not providing it to dispute anything dirty birdy said. I am simply posting the text up because I found the paragraph interesting. And I found the very last sentence most interesting.
I recognize the probable reality that when the information was written, that the person providing the information; probably never even considered ‘yoyos’ as one of those potential applications for 7068.
Regardless; it provides a pretty impressive view of 7068🤓
7068 Ultra-Strength Aluminum – The Ultimate Alloy
Circa 2000, the Ordnance industry requested development of an ultra-high strength, lightweight alloy with corrosion resistance equal or better than 7075. In response, Tennalum Inc. (a division of Kaiser Aluminum Corp.) developed an ultra-strength alloy called 7068-T6511 – commonly known as Tennalum® 7068. With a yield strength of 99 KSI (683MPa) it has the highest mechanical strength of all commercially available aluminum alloys (2.5 times stronger than 6061, and 35% stronger than 7075) and exceeds that of many steels. In fact, it’s yield strength is approaching that of pre-hardened (HRC 26-32) 41XX and 400 series stainless steels but at a third of the weight. In strength-to-weight ratio, Tennalum® 7068 out performs nearly all other engineering alloys in existence (33% better strength-to-weight performance than 7075, and 28% better performance than 6Al-4V Grade 5 Titanium). However, due to its higher cost (3-4 times that of 6061) and limited availability, it has seen very little commercial use. But for many applications there is no better alloy, not even Titanium.
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Happy to help, and keep folks on the straight and narrow, technically speaking!
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I really want Julio to join in in this conversation.
He’s the one that’s actually used it for making yoyos.
7068 has a huge potential, is relatively new compared with other alloys, I believe that is the main reason for not being used in yoyos until now. Making a yoyo with new material is not an easy task because you have to invest in prototypes to try how it really is in practical terms and how it holds anodizing. If it happen that the material wasn´t that good, you end up losing money.
7068 prices are getting down every year because the demand is increasing. It is replacing aluminum 7075 because it as virtually the same density and is better in every single useful property (as far a i know). I don´t see why it won´t happen with yoyos. The difference in price is small and getting down.
So far, I think is the best aluminum alloy to make yoyos with.
I dont think 7068 will replace 6061 though, as 7075 hasn´t replaced it. 6061 is considerably cheaper and you can still make a good designs with it, there is no need to increase the price unless you want to go with crazy thin walls and want to make it tougher.
So it is 7075 that is pretty much doomed unless the price gap gets wide.
While 6061 has not reached it’s peak of potential, I do think overpriced 6061 Al yoyos now are simply absurd. There is no reason to charge a fortune for a 6061 Al yoyo any more, as there are many 7075 yoyos out there that out perform many of these yoyos for a fraction of the cost. The Shu Ta, while not the cheapest 7075 out there, is still very affordable at around $75, and is a great performer. The Cyborg is another example, at only $50, it has the same level of performance as more expensive Turning Points. Sure manufacturing in Japan is expensive, but Yoyorecreation does not charge as much as Turning Point does, and they use a superior alloy in their yoyos as well. Sengoku managed to put out a yoyo made of 7068, which is more expensive than both 7075 and 6061, for less than what CLYW charges for a yoyo made of an inferior alloy. Simply put, I believe that premium yoyos should also be made higher quality materials. Also, I think it’s silly to say a yoyo made of a superior alloy isn’t better than a yoyo made of an inferior alloy, when the same designer makes the yoyo. Yes, the design of the yoyo greatly affects how it’ll perform, but the material used has a large part as well. 6061 may be preferred or even superior in some cases, but in yoyos I do not believe that is the case.
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I don’t think 6061 is necessarily inferior to 7075. Some people like the “softer” feel, and it’s easier to anodize.
That’s very true, but strength to weight ratio wise, 6061 is inferior. And I think the trouble anodizing 7075 isn’t as prevalent now. I’ve had many yoyos made from 7075 where the anodizing was perfect.
For some of the smaller companies the even getting the price of 6061 Al yoyos down below 100 can be hard for them. They don’t have the money to make larger runs to support bringing the cost down.
However, what you get with these smaller companies is more of a heart poured into the designs.
Sometimes 6061 shouldn’t be priced so high and sometimes it can’t be avoided.I don’t think we will see a decrease in the price of 6961 yoyos until the community get large enough so that there is more of a demand for larger yoyo runs.
I think the play feel of 6061 is really soft. Its a really good feel. However, the poor durability of it bothers me. It’s quite easy to damage . Its a major bummer paying 100 or over for a 6061 throw, and one fairly insignificant instance of contact with your wedding ring can ding it.
This!