A234 Carbon Equivalent (CE) & Weldability Calculator

ASTM A234 caps the carbon equivalent at 0.50 and requires it on the mill test certificate. Enter your heat analysis to check weldability.

Per ASTM A234/A234M the carbon equivalent shall not exceed 0.50 and is reported on the mill test certificate. A CE near or above 0.50 signals the need for preheat and controlled heat input; values comfortably below weld with less risk of hydrogen cracking. This is the standard’s own weldability control, not a vendor add-on. Synbase reports the measured CE on every CMTC.