Basics of Grinding Wheel
Constituents of grinding wheel
Grinding wheels are made of 3 elements _grain, bond, pore.
These elements can be described by 5 factors, which are written on specifications.
3 elements
- Grain Cutting edges
- Bond Holder of the cutting edges
- Pore Plays role of chip pocket
5 factors
- Type of abrasive
- Grit size
- Hardness grade
- Structure (vol.% of abrasive)
- Type of bond

Display Method of Grinding Wheel Specifications (JIS)

Grinding Wheel Shape Codes and Names (JIS R6242) [ ↑Usage Surface ]
Type 1 Flat | Type 2 Ring T≧W | Type 3 Single-Tapered |
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Type 4 Double-Tapered | Type 5 Single Concave | Type 6 Straight Cup |
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P≧フランジ径 X 1.02+4 ![]() E≧T/2 |
![]() E≧T/4 W≦E |
Type 7 Double Concave | Type 7 Double Concave | Type 11 Tapered Cup |
P≧フランジ径 X 1.02+4
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![]() E≧T/4 |
K≧フランジ径+2R ![]() E≧T/4 W≦T |
Type 12 Dish | Type 13 Saw Dish | Type 20 Single Relief |
K≧フランジ径+2R ![]() E≧T/2 |
K≧フランジ径+2R ![]() U=E R≧U/2 |
K≧フランジ径+2R ![]() E≧T/2 |
Type 21 Double Relief | Type 22 Single Relief Single Concave | Type 23 Single Concave Relief |
K≧フランジ径+2R ![]() E≧T/2 |
P≧フランジ径 X 1.02+4 ![]() E≧T/2 |
P≧フランジ径 X 1.02+4 ![]() E≧T/2 |
Type 24 Single Relief Double Concave | Type 25 Double Relief Single Concave | Type 26 Double Relief Double Concave |
P≧フランジ径 X 1.02+4 ![]() E≧T/2 |
P≧フランジ径 X 1.02+4 ![]() E≧T/2 |
P≧フランジ径 X 1.02+4 ![]() E≧T/2 |
Type 27 Offset | Type 28 Offset | Type 31 Segment |
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Type 35 Disk | Type 36 Disk with Nut | Type 37 Ring with Nut |
接着又は機械的に取り付け ![]() |
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Type 38 Single Dovetail | Type 39 Double Dovetail | Type 41 Flat Cutting Wheel |
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Type 42 Offset Cutting Wheel | Type 52 Mounted Wheel | Type 54 Honing Wheel |
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Type 90 Hand Grinding Wheel | ||
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研削砥石の標準縁型形状
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A | B | C | D | E | F | G | H |
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I | J | K | L | M | N | P |
Safety information
Prohibitions during transport (3 rules)
- Do not roll
- Do not drop
- Do not crash
Storage Precautions
- Avoid hitting
- Avoid too much stacking
Regulations
- NEVER use wrong surface of the grinding wheel.
- NEVER exceed max. speed stated by manufacturer.
- Always mount on the proper flanges.
- Always idle for 1 min before you actually start grinding.
Idling shall be more than 3 min when the wheel is exchanged.

Sound check
- Use non-metallic hammer
- Tap the points shown above
(Tap entire circumference if possible) - Tapping shall be very lightly
Basics of Super-abrasive Wheel
Shape code of the super abrasive wheels (JIS-B4131)
Shape code consists of following 4 parts.
- Basic core shapes
- Shapes of abrasive cross section
- Location of abrasive section
- Modification

Basic Core Shapes and Numerical Codes
Cross-Sections of Abrasive Layer and Alphabetical Codes
A | ![]() |
D | ![]() |
FF | ![]() |
L | ![]() |
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AH | ![]() |
DD | ![]() |
G | ![]() |
LL | ![]() |
S | ![]() |
B | ![]() |
E | ![]() |
H | ![]() |
M | ![]() |
U | ![]() |
C | ![]() |
EE | ![]() |
J | ![]() |
P | ![]() |
V | ![]() |
CH | ![]() |
F | ![]() |
K | ![]() |
Q | ![]() |
Y | ![]() |