Special Boring Grades
**7 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.
**8 Briquetted cast iron borings, hot process.
Cast iron borings, heated,briquetted, to a density of approximately
*5 percent, oil and water
content under one percentt.
**9 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 *0 percent.
**0 Malleable borings.
Clean malleable iron borings and drillings, free of steel turnings,
scale, lumps and excessive oil.
**1 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.
