FighterAce wrote:So what would be the preferred method for joining a 15mm OD, 1.6mm wall drawn Cu pipe with a thread to pipe fitting? Operating pressure around 800psi.
Honestly, I would say solder it. If the joint is .25" long (conservative), that gives you .4638 sq in of shear area. The shear strength of 50/50 lead tin solder is 5220 PSi, so the strength of the joint would be 2421 lbs.
The cross section area in this case is .678 in, so your fail pressure is 3570 PSI. This gives you a safety factor of 4.4. (Check my calculations anyway)
If this is for a barrel, it will never see the full working pressure along its axis; there is nowhere for the pressure to act to pull the joint apart except from projectile friction.