Gas metal arc welding uses constant voltage. Tungsten inert gas welding does not use constant circuit voltage.

When size of smallest hole is more than size of biggest shaft n it is clearance fit.

The oxy acetylene gas welding is a type of exormic reaction. 1 mole of acetylene can produce KJ/mol of heat.

The arc spot or ?puddle? weld is started by striking an arc on deck surface, causing a hole to form in deck. The weld operation n continues by depositing electrode material on beam or joist and allowing molten ?puddle? to engage penetrated deck.

Resistance welding is inherently autogenous as re is no convenient way to apply a filler material.

Oxidizing welding flames are produced when slightly more than one volume of oxygen is mixed with one volume of acetylene. Oxidizing welding flames are commonly used to weld zinc, copper, manganese steel, cast iron, etc.

When size of smallest shaft is more than size of biggest hole n it is interference fit.

The inner cone of flame has highest temperature (3500°C). The outer flame has lowest temperature.

Weld metal in excess of quantity required to fill a joint. This can be machined for a good surface finish.

Minimum material limit of shaft is minimum diameter of shaft. Maximum material limit of shaft is maximum diameter of shaft.