Aircraft spruce 3003 tubing question

[JoeB]

Below is the listing for the soft tubing VANS sells us from the Spruce website.

What is a Safety Factor of 2???



3003-O VERSATUBE
Soft aluminum tubing for instrument air and vacuum lines, fuel and oil lines, and primer lines

If mfg test reports are required there is a minimum $15.00 charge per order. Charge is higher if more than 5 items. P/N is ?certs? - please indicate at time of order in the special instructions box.

*Safety factor of 2.

[krw5927]

That is a footnote to their table on max working pressures for each diameter/wall thickness.

For instance, they are claiming that the 3/8" diameter, .035" wall tubing is suitable for a max working pressure of 520 psi, and that there is a safety factor of 2 on that pressure. Meaning it will fail at around 1040 psi.

[BillL]

Well the lawyers answer is , well . . . 2.

Note that it is referring to the working pressure column. That means that pressure is 1/2 of the yield stress.

[mburch]

I always thought it meant you should order twice as much as you think you'll need because you'll be making a lot of scrap.

[krw5927]

If that's the case, Matt, my "safety factor" would be somewhere between 3-4. Maybe higher.

That must mean I'm EXTRA safe!