This specification defines the requirements for selecting and evaluating mineral and slag abrasives used for blast cleaning steel and other surfaces for painting and other purposes.
The abrasives covered by this specification are primarily intended for one-time use without recycling; reclaimed materials must again be tested against and meet the requirements of this specification. (See Note 7.1.)
The abrasives are categorized into two types, three classes and five grades as described below. Normally the user shall specify the types, classes and grades required. If no abrasive type is specified, then either Type I or Type II is considered acceptable. If no abrasive class is specified, then any class will be considered acceptable. If no abrasive profile grade is specified, the abrasive shall satisfy the requirements of any of the five grades listed.
The following abrasive types are included.
Type I - Natural Mineral Abrasives These are naturally occurring minerals, including, but not limited to, quartz sands, flint, garnet, staurolite, and olivine.
Type ll - Slag Abrasives These are slag by-products of coal-fired power production or of metal (such as copper or nickel) smelting.
The following abrasive classes are included.
Class A - Crystalline silica less than or equal to 1.0%
Class B - Crystalline silica less than or equal to 5.0%
Class C - Unrestricted crystalline silica
The definition and requirements for Classes A, B and C are given in Section 4.2.
The abrasive grades and associated profile ranges are listed below:
• Grade 1 - Abrasives which produce surface profiles of 0.5 to 1.5 mils (13 to 38 micrometers) when tested in accordance with Section 4.3.
• Grade 2 - Abrasives which produce surface profiles of 1.0 to 2.5 mils (25 to 64 micrometers) when tested in accordance with Section 4.3.
• Grade 3 - Abrasives which produce surface profiles of 2.0 to 3.5 mils (51 to 89 micrometers) when tested in accordance with Section 4.3.
• Grade 4 - Abrasives which produce surface profiles of 3.0 to 5.0 mils (75 to 127 micrometers) when tested in accordance with Section 4.3
• Grade 5 - Abrasives which produce surface profiles of 4.0 to 6.0 mils (102 to 152 micrometers) when tested in accordance with Section 4.3.
Other profile ranges may be designated by the purchaser.
