When starting a cut on a plate, how high should the preheat cones be held above the surface?

When starting a cut on a plate, holding the preheat cones about 3 mm above the surface is optimal for ensuring that the material is adequately heated. This height allows for effective penetration of the heat into the metal without causing excessive heat loss or affecting the integrity of the preheated area.

At this distance, the preheat flames can create a reliable heat zone, making it easier to initiate the cutting process and maintain a steady flame while cutting. If the preheat cones are held too close, they may produce localized overheating, leading to distortion or damage to the surface, while being too far away can result in insufficient heating, making the cutting process difficult and ineffective.

This balance of heat application is crucial for ensuring efficient cutting and achieving a clean edge, which are important in welding and metal fabrication processes. Proper training in handling the equipment and understanding the heating dynamics can significantly improve the quality of work and safety in the welding environment.