Nicolas Heinz
Dec. 15, 2020
1:33 a.m. PST

Interface Thread material

Dear Sir or Madame,

I have a question regarding the accepted material or the Interface Threads. In your Small Payload users guide you state that they have to be of "ALUMINUM 7075-T7351 OR STRONGER".
The commercial Aluminum alloy such as Aluminum 7075-T6 is equally strong/stronger. is this alloy acceptable as well?

Best regards

Nicolas Heinz
3 Replies

Kyla Jeffrey HeroX team
Dec. 15, 2020
1:33 a.m. PST
The difficulty with 7075-T6 is that it is not amenable to any additional heat treatment and can have substantial drops in strength if heated after the T6 conditioning. We recommend 7075-T7351 because it can be stress relieved after forming.
Tagged: Nicolas Heinz

Nicolas Heinz
Dec. 15, 2020
1:33 a.m. PST
Thank you for your Answer.
Does that mean its prohibited to use the 7075-T6 for our Interface threads?
The reason being that 7075-T6 is easier to obtain and cheaper to mill externally.

Thanks in Advance

Kyla Jeffrey HeroX team
Dec. 15, 2020
1:33 a.m. PST
Using 7075-T6 and milling could be problematic. The milling will impart residual stress. With T-6, you cannot stress relieve without losing strength. Without stress relief during the extreme cycles that could be encountered on the moon it is likely that the residual stress will relieve itself through warpage, which could be problematic.
Tagged: Nicolas Heinz
Post Your Reply
Let these people know about your message