Sectional View of Tapping Crucible Thermit Welding Small 320×169 Medium 640×338 Large 1024×541 Download TIFF Original 2400×1268 | (384.8 KB) Description A cross sectional view of tapping a crucible in thermit welding. The crucible is placed over a mold to fasten two metals together. This method is commonly used to combine two railroad tracks. Keywords Metalworking Crucible, Railroad Track Welding, Thermit Welding, Thermit Welding Crucible, Welds Galleries Blacksmithing and Metalwork Source: Encyclopaedia Britannica (12th ed., vol. 32) (New York, NY: The Encyclopaedia Britannica Company, 1922)