Can any one give information that, in saw process minimum base metal thickness required for Dia 1.6 mm filler wire welding

Regards,
Ruban

You have to establish the thickness by actual welding as it depends on your setup & facilities . Also whether you are joggling the plate - see figure UW13.1(i) . You have to set travel speed to achieve full penetration & this depends on your arrangements.

To give an idea ,domestic LPG tanks (15 kgs gas ) are welded by this method.