Special Boring Grades
267 No. 1 chemical borings.
New clean cast or malleable iron borings and drillings containing not more than 1 percent oil, free from steel turnings, or chips, lumps, scale, corroded or rusty material.
268 Briquetted cast iron borings, hot process.
Cast iron borings, heated,briquetted, to a density of approximately 85 percent, oil and water
content under one percentt.
269 Briquetted cast iron borings, cold process.
Cast iron boring briquettes,free of steel and nonferrous material, hydraulically compressed
into a cohesive solid, reasonably free of oil, and having a density of not less than 60 percent.
270 Malleable borings.
Clean malleable iron borings and drillings, free of steel turnings, scale, lumps and excessive oil.
271 No. 2 chemical borings.
New clean cast or malleable iron borings and drillings, containing not more than 1.5 percent oil, free from steel turnings, or chips, lumps, scale, corroded or rusty material.