The specification marking system was developed by the ANSI (American National Standards Institute) to make it easy to identify material specifications in abrasive products like grinding and cut-off wheels.
The naming system incorporates 4 different specifications types in a simple shorthand so it takes up little space, and is fast and easy to read. They are always in order from left to right indicating: Primary Grain Type, Grit Size, Hardness Level and Bonding Material.
Following is an example of how to read a specification marking and a table with the most common specifications for easy reference to aid in understanding these markings.
Specification Marking System Example: A-24-Q-BF
Read it as: [GRAIN (A)]-[GRIT (24)]-[HARDNESS (Q)][BOND (BF)]
This product's grain is Aluminum Oxide; grit is coarse at 24; has a hardness rating of hard, at a Q level, and is bonded together with resin and is also reinforced.
Where the dashes go is arbitrary; the system is arranged so that each section follows the same order with or without the dashes.
|ANSI MARKING SYSTEM:|
|A - Aluminum Oxide||Coarse||Soft||B - Resinoid|
|AT or TA - Ceramic Aluminum Oxide||14||D||BF - Resinoid Reinforced|
|C - Black Silicon Carbide||16||E||E - Shellac|
|CA or AC - Aluminum Oxide and Silicon Carbide Mixture||20||F||O - Oxychloride|
|GC - Green Silicon Carbide||24||G||R - Rubber|
|Z or ZA - Zirconia Aluminum Oxide||H||RF - Rubber Reinforced|
|Medium||Medium||S - Silicate|
|30||I||V - Vitrified|