Q. I am about to try and make my living at building high performance ATV chassis', a-arms, and swingarms. My question is ...if building them out of 4130 chrome-moly tubing with a wall thickness of about .095, will I need to heat treat or normalize the chassis? I was told there would be no need to treat the smaller a-arms and swing-arms, but what about the chassis, and if so how would I go about treating them? Thank you for any help. (Submitted by: Jeff Munsch from Unknown)


A. Sounds like you have a big project ahead of you! If you keep the heat input to a minimum, you shouldn't have to stress relieve. Keep all joints tight and don't weave the weld. Keep your arc length as low as possible and use an ER70S-6 or an ER80SD-2 filler and straight Argon for gas. No Helium. Helium adds arc energy which is bad for Chrome-Moly. If you feel you must stress relieve, use around a 1000 deg to 1100 deg temp stick and lightly torch the joint. Good luck and have fun!