The tip of an oxyacetylene cutting torch should be held at what angle when cutting cast iron?

The tip of an oxyacetylene cutting torch should be held at what angle when cutting cast iron?

• A. 45°
• B. 60°
• C. 90°
• D. 120°

Answer: (C)

In oxyacetylene cutting, how you hold the torch affects where and how heat and the cutting oxygen interact with the metal. For cast iron, you want heat concentrated right at the cut line and the cutting oxygen directed straight along that line. Holding the tip perpendicular to the work achieves this: it focuses the preheat heat exactly at the kerf and lets the oxygen jet blow molten metal away along the intended path, giving a cleaner, steadier cut and reducing thermal stress. If the torch is tilted, heat spreads more across the surface and along a wider area, making preheating less uniform and increasing the risk of an uneven cut or cracking in the brittle cast iron. The perpendicular orientation keeps heat input controlled and the cut line well defined, which is especially important with cast iron.

In oxyacetylene cutting, how you hold the torch affects where and how heat and the cutting oxygen interact with the metal. For cast iron, you want heat concentrated right at the cut line and the cutting oxygen directed straight along that line. Holding the tip perpendicular to the work achieves this: it focuses the preheat heat exactly at the kerf and lets the oxygen jet blow molten metal away along the intended path, giving a cleaner, steadier cut and reducing thermal stress.

If the torch is tilted, heat spreads more across the surface and along a wider area, making preheating less uniform and increasing the risk of an uneven cut or cracking in the brittle cast iron. The perpendicular orientation keeps heat input controlled and the cut line well defined, which is especially important with cast iron.