Micro plasma arc welding (micro PAW) was carried out AM 350 precipitation hardening alloy to produce an edge-joint weld. The application of micro PAW technique was also demonstrated in the present work. The results indicated that the arc voltage increased with increasing quantity of added hydrogen in the argon atmosphere. The collimated shape of low current plasma arc was mainly responsible for the low sensitivity of weld shape to variations in arc length. The edge welded bellows of AM 350 alloys have been successfully welded using the present micro PAW technique.