keris forging crack
 

Hi, anyone has experience that why new keris will have forge crack?

Depends on the type of crack Anthony, but common causes in forged work are material, ie, iron & steel, that is known as "hot short", in other words it does not forge easily and is subject to cracking under the hammer.

The second very common cause of a perceived crack is called a "cold shut". This occurs when the material is not at optimum temperature to achieve a weld, and/or the surfaces to be welded are insufficiently clean and/or a flux has not been used where it was necessary. A cold shut is not really a crack, but it often looks like one.

Hi Alan, thanks for sharing.

My pleasure.

Some good photos of the crack would probably aid a discussion. ;)

You can also have perpendicular cracks to the edge, that can be identify by a too hot quench of the blade.

JBG, I believe that if you care to test the base cause of this type of longitudinal crack you will find that it is evidence of a cold shut, the stresses of heat treatment merely expose this cold shut.