Where should I start when selecting a grinding wheel?

Start with the workpiece material and the operation (roughing, cutting-off, surface grinding, sharpening, finishing). Then choose the abrasive grain type, an approximate grit range, and the wheel hardness grade for your grinding conditions.

How do I choose the abrasive grain type for different materials?

Match grain type to the material: aluminum oxide is commonly used for steels; zirconia and other high-performance grains are used for heavy stock removal; silicon carbide is often used for cast iron, brittle materials, and many non-ferrous applications. Always consider heat generation and loading tendency.

How does grit size affect stock removal and surface finish?

Coarse grits remove material faster but leave deeper scratches. Finer grits reduce scratch depth and improve surface finish, making them suitable for finishing, honing, and polishing preparation.

Which grit range is suitable for roughing, cutting, and surface grinding?

Roughing typically uses coarse grits; cutting-off and face grinding use medium-to-coarse grits depending on the task; finishing surface grinding uses finer grits. The best grit range depends on the required removal rate and target roughness.

What does grinding wheel hardness mean?

Hardness describes how strongly the bond holds abrasive grains. Softer wheels release dull grains sooner and self-sharpen more easily, helping reduce loading. Harder wheels hold grains longer but may glaze, overheat, or lose productivity if mismatched.

Why does a wheel load up or glaze, and how can I reduce it?

Common causes include an unsuitable grain type, grit that is too fine for heavy removal, incorrect hardness grade, excessive feed, or poor chip/heat evacuation. Solutions include adjusting grit and hardness, changing grain type, dressing the wheel, and optimizing grinding parameters.

Why do I need GOST to FEPA conversion tables?

Different products and documents may use different standards. Conversion tables help match GOST and FEPA markings correctly and select an equivalent grit range when ordering or comparing abrasives.

How do I build a grit progression from rough to finish?

A typical workflow moves from coarse to finer grits so each step removes scratches from the previous one. The number of steps depends on the initial surface condition and the required finish. Avoid overly large jumps between grits to keep the process efficient and predictable.

How to Choose a Grinding Wheel: Grain Type, Grit and Hardness (GOST/FEPA)

March 24, 2026
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Selection of Abrasive Material, Grit, and Hardness for Grinding Wheels

Abrasive Wheel Selection: Grain Type, Grit Range, and Hardness

Choosing the right abrasive wheel is a combination of three core parameters: abrasive grain type, grit size, and wheel hardness. If one parameter is mismatched, you may get low productivity, overheating, wheel loading (glazing), fast wear, or inconsistent surface quality.

The reference tables below help you:

compare GOST and FEPA markings;
select an approximate grit range for your operation (rough grinding, cutting-off, face grinding, sharpening, finishing, honing, polishing preparation);
choose hardness grades based on the operation type and grinding conditions.

1) Abrasive grain type selection

Grain type determines cutting behavior, heat sensitivity, edge retention, and wear pattern. Different materials (steel, stainless steel, cast iron, non-ferrous metals, hard alloys, brittle materials) require different abrasive grains.

Abrasive grain grade		APPLICATION
GOST	FEPA	APPLICATION
14A	A	Processing materials with high tensile strength; rough grinding of steel castings and rolled products; high-strength cast irons; processing carbon and alloy steels; bronze; nickel and aluminum alloys.
25A	WA	Grinding hardened parts made of carbon, high-speed and stainless steels. Processing thin parts and tools (gears, knives, drills, cutters); sharpening.
38A	ZK	Heavy-duty rough grinding of steel workpieces (high stock removal).
54C; 63C	C; GC	Processing hard materials with low tensile strength (cast iron, bronze, brass, hard alloys, glass, precious stones, marble, granite, porcelain), as well as very ductile materials (heat-resistant steels and alloys, copper, aluminum).

2) Grit size selection

Grit size affects cutting depth, material removal rate, and surface finish. Coarse grits are used for aggressive stock removal; finer grits are used for finishing and preparation for polishing.

Grit		OPERATION TYPE
GOST	FEPA	OPERATION TYPE
200-80	F10-F22	Rough grinding with large cutting depth; cleaning workpieces and castings. Processing materials that tend to glaze/load the wheel surface (brass, copper, aluminum).
80-50	F22-F36	Cutting-off; face grinding; tool sharpening; dressing of abrasive tools.
63-25	F30-F60	Pre-grinding and combined grinding; sharpening of cutting tools.
40-5	F40-F220	Flat/surface grinding.
32-16	F54-F90	Finish grinding; processing profiled surfaces; sharpening small tools; grinding brittle materials.
12-6	F100-F180	Finishing grinding; lapping of hard alloys; finishing of cutting tools; finishing steel workpieces; sharpening thin blades; pre-honing.
6-M50	F180-F280	Finishing grinding of metals, glass, marble, etc.; thread grinding; finish honing.
M63-M14	F230-F600	Superfinishing; final honing; finishing thin blades; thread grinding with fine pitch; polishing preparation.

3) Hardness grade selection

Wheel hardness determines how the wheel “opens” (self-cleans) and how stable it cuts in your process. Different operations require different hardness grades depending on heat load, pressure, and whether the surface is continuous or interrupted.

Hardness		OPERATION TYPE
GOST	FEPA	OPERATION TYPE
ЧТ;ВТ	W;T	Rough grinding operations; dressing abrasive tools; grinding bearing balls.
Т2;Т1; СТ3;СТ2	S;R;Q;P	Cutting-off; groove cutting; manual rough grinding; external cylindrical grinding; centerless grinding; grinding interrupted surfaces.
СТ2;СТ1; С2	P;O;N	Preliminary external cylindrical and centerless grinding of steel and malleable cast iron; profile grinding; grinding interrupted surfaces; honing and thread grinding with a large pitch.
СТ1;С2; С1	O;N;M	Surface grinding with segments and ring wheels; thread grinding with resin-bond wheels.
С2;С1; СМ2;ЗМ1	N;M;L;K	Finish and combined external cylindrical, centerless and internal grinding of steel; surface grinding; thread grinding; sharpening cutting tools.
CM2;CM1; M3	L;K;J	Sharpening and finishing carbide-tipped cutting tools; grinding difficult-to-machine special alloys; polishing preparation.

4) Abrasive grit table (GOST / FEPA) with main fraction size (µm)

The table below provides a practical reference for grit markings and the main fraction grain size in microns. It helps compare standards and estimate grit ranges when selecting abrasive tools.

GOST 52381-2005		FEPA 42D
grit	main fraction grain size, µm	grit	main fraction grain size, µm
abrasive grains
№200	2500-2000	F10	2400-2000
№160	2000-1600	F12	2000-1700
№125	1600-1250	F14	1700-1400
-	-	F16	1400-1180
№100	1250-1000	F20	1180-1000
№80	1000-800	F24	850-710
№63	800-630	F30	710-600
№50	630-500	F36	600-500
-	-	F40	500-425
№40	500-400	F46	425-325
№32	400-315	F54	355-300
№25	315-250	F60	300-250
№20	250-200	F70	250-212
№16	200-160	F80	212-180
-	-	F90	180-150
abrasive powders
№12	160-125	F100	150-125
№10	125-100	F120	125-106
№8	100-80	F150	106-75
№6	80-63	F180	90-75
№5	63-50	F220	75-63
micro abrasive powders
M63	63-50	F230	63-53
M50	50-40	F240	53-44.5
-	-	F280	44.5-36.5
M40	40-28	F320	36.5-29.2
-	-	F360	29.2-22.8
M28	28-20	F400	22.8-17.3
M20	20-14	F500	17.3-12.8
M14	14-10	F600	12.8-9.3
M10	10-7	F800	9.3-6.5
M7	7-5	F1000	6.5-4.5
M5	5-3	F1200	4.5-3
M3	3-2	-	-
M2	2-1	-	-
M1	1-0	-	-

Practical tips: how to make a quick selection

Start from the workpiece material: steel, stainless, cast iron, non-ferrous metals, hard alloys, brittle materials — this determines the grain type.
Define the operation: roughing, cutting-off, face grinding, surface grinding, sharpening, honing — this narrows the grit range.
Check the grinding conditions: manual vs machine, continuous vs interrupted contact, heat sensitivity — this affects hardness selection.
If the wheel loads up: re-check grain type, grit, and ensure proper chip/heat evacuation.

For a precise selection (material grade, batch size, target roughness, and productivity), consulting a technologist is recommended—similar grit codes can behave differently depending on the process.