Class 1 Tungsten Heavy Alloy (WHA) Block 2.37”T x 4.9″W x 6.2″L (Rough As Sintered Finish). Tolerance +/- 3/16″. Made in the USA at Elmet’s Lewiston Maine facility. Elmet is the sole fully integrated US owned and operated primary producer of B-777 tungsten material. ASTM B-777 Class 1 Type 2. MIL-T-21014D Class 1 Material. 90% Tungsten by Weight. See data sheet for detailed specs. Elmet is ISO 9001, AS9100C and ITAR compliant.