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 1 percent.

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.