Wheel Specifications
Every grinding wheel carries a standardized code that identifies its shape, dimensions, abrasive type, grit, and bond — so you can quickly identify the right wheel, verify stock availability, or request a custom-made wheel. FM Carbide wheels use two different marking standards depending on the abrasive: superabrasive wheels (diamond & CBN) are marked per FEPA, and conventional abrasive wheels (aluminum oxide & silicon carbide) are marked per ANSI/ISO. Both are explained below.
The following is a simple guide and an example that helps define and select the shape and dimension of a superabrasive grinding wheel univocally, according to FEPA (Federation of European Producers of Abrasives). It is now possible to quickly identify the wheel necessary for your application, verify its availability at stock, or simplify the request for custom-made wheels.
| F | V | OD | W | X | T | H |
|---|---|---|---|---|---|---|
| 11V9 | 20° | 100 | 10 | 3 | 35 | 31.75 |
Conventional abrasive wheels — made with aluminum oxide or silicon carbide instead of diamond or CBN — use a different code, standardized under ANSI B74.13 (and closely mirrored by ISO 525). The code is stamped or printed directly on the wheel and, read in order, tells you exactly what the wheel is made of and how it will perform.
| Code Position | What It Means |
|---|---|
| Abrasive Type | Letter identifying the abrasive mineral. Common types: A = Aluminum Oxide, C = Silicon Carbide, Z = Alumina Zirconium, SG = Seeded Gel (ceramic). |
| Grit Size | Number indicating abrasive particle size — the higher the number, the finer the grain. Coarse: 8–24 · Medium: 30–60 · Fine: 70–180 · Very Fine: 220–600. |
| Grade | Letter (A–Z) rating how strongly the bond holds the grains — i.e. bond hardness. Roughly: Soft = A–H, Medium = I–P, Hard = Q–Z. |
| Structure | Number (typically 1–15) rating how tightly the abrasive grains are packed. Lower = dense/closed structure, higher = open/porous structure. |
| Bond Type | Letter identifying the bonding agent that holds the grains together: V = Vitrified, B = Resinoid, BF = Resinoid Reinforced, R = Rubber, RF = Rubber Reinforced, S = Silicate, E = Shellac, O = Oxychloride. |
Aluminum Oxide, grit 24 (coarse), grade R (hard bond), Resinoid Reinforced bond. A manufacturer may add a structure number between grade and bond (e.g. a "7") on wheels where that spec is specified.Source: ANSI B74.13 conventional abrasive wheel marking chart.
Not sure which wheel or marking you need? Send us your application details or the code on your current wheel and we'll confirm stock or quote a custom-made wheel.