How to choose right grinding wheels:

In modern industry, grinding wheels are the essential abrasive tools. In spite of the accuracy of your machine, and even you buy the most famous brand in the world, if the grinding wheel you choose is not right, you cannot get the best grinding effect. So, it is so important to make right choice for grinding wheels. A particular grinding wheel is not all-purpose. Grinding wheels of different materials have different character. Firstly, you must understand the grade of steel so as to choose correct abrasive material of grinding wheel. Then, by requirements of your machine, technology, and the HRC hardness of steel to grind, you can determine the grit, hardness and structure of the grinding wheel. Only if you make such correct choice, you can get the best grinding effect. And the accuracy of your work piece can be improved. You’ll be more productive and the cost is lowered. This makes your product more competitive. Our professional engineers and technicians can help you to make right choice of grinding wheels and would be always ready to offer right solution to your questions on grinding.

Roughly, there are more than 100,000 specifications of grinding wheels on worldwide markets. In order to avoid any mistake of ordering, here are the general marks of the specification:

specification

 

 1   –350x40x127mm       A60          K       5      V      -35m/s

Type                       Size: DxTxH                     Grain code & Grit No.   Hardness,     Structure,        Bond,         Rotary speed.

 

 Let’s decode these parameters as below:

Shapes (Types) and the codes of grinding wheels 

Shape Shape code  Drawing   Shape  Shape code  Drawing
Straight wheel  Type 1  Type 1   Recessed wheels on both sides  Type 7  Type 7
Straight wheel with Arc face  Type 1F Type 1-F    Dish wheels  Type 12  Type 12
Cylinder wheel  type 3  Type 2   Flaring cup wheels  Type 11  Type 11
Wheels tapered two sides  Type 4  Type 4   Convexed wheels(one side)  Type 38  Type 38
Recessed wheels(one side)  Type 5  Type 5   …….  …….  …………
Cup wheels  Type 6  Type 6   ………  ………..  ………….
         

 

Abrasive grains and its code, character, purpose:

Code

Abrasive grains

Character

Purpose

A

Brown fused alumina

Higher hardness   & toughness.

Abrasive products   made of A are suitable for the   grinding of carbon steel, malleable iron, alloy   steel, hardened   bronze, etc.

WA

White fused alumina

Its hardness is a   little higher, but toughness   is slightly lower than tha of A. The grains are relatively   easier to   be fractured. With sharper edge, it gets higher cutting ability,   and   lower heat generated on grinding. 

It is used for   grinding the steels of great   hardness, such as high carbon steel, alloy   steel, and high speed   steel. Mainly, it is used for grinding tools, knives,   molds, gear,   thread, thin-wall parts, etc.

PA

Pink fused alumina

Hardness is   similar to WA, but toughness is   higher than WA. The grain can keep its sharp   edge more strongly. Life   band is longer.

Grinding wheels   made of PA are suitable for   precision grinding of measuring tools, lath main   shafts, instrument   parts, threads, and also for profiling.

SA

Single crystalline fused alumina

Comparing to A   & WA, SA get much more high   hardness, toughness, and impact strength. Most   grains are globular   single crystal. And they have multi-edge for cutting.

It is particularly   adaptable for the grinding of   stainless steel, high vanadium-high speed   steel, and is especially   used for grinding of easy-deformed and easy-burnt   parts.

MA

Microlite fused alumina

The grains of MA   are composed by micro crystal.   Toughness and impact strength are high. Very   good at self-sharpening.

Grinding wheels   made of MA are mainly for   snagging operations in steel mills and for   heavy-pressure, forming and   in-feed grinding of such materials as stainless   steel, carbon steel,   bearing steel, and ductile cast iron, etc.

A/WA

Mix of Brown/White fused alumina

Mixing them can   get combination of the   advantages of both A & WA.

Grinding wheels   made of A/WA are suitable for   grinding ductile iron crankshaft, cam shaft,   bearing, etc.

GC

Green silicon carbide

Higher purity,   High hardness, brittle, sharp,   very good at heat conductivity.

Grinding wheels   made of GC are suitable for   processing hard and brittle non-metalic work   piece, such as cemented   carbide, optical glass, ceramics as well as hard   alloy and non-ferous   metal, etc.

C

Black silicon carbide

High hardness,   brittle, sharp, can  conduct   heat.

Grinding wheels   made of C are suitable for the   grinding of non-ferrous metal and nonmetallic   materials.

 

 

Grit No.

Coarse Medium Fine Super fine Micro powder
10,12,14,16,20,24 30,36,46,54, 60, 70 80,90,100,120,150,180,220 240,280,320,400,500,600,700,800 1000,1200,1500,2000,2500,3000,4000,6000,8000

 

 

Hardness grade

Extra soft Soft Medium Hard Extra hard
A,B,C,D,E,F,G H,I,J,K L,M,N,O P,Q,R,R, T,U,V,W,X,Y,Z

 

 

Structure No.

Structure No. 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
Proportion of abrasive grains (%) 62 60 58 56 54 52 50 48 46 44 42 40 38 36 34

 

 

Bond (bonding)

Type Code Characteristic
Vitrified bond V Strong bonding strength, good rigidity,   slightly brittle, suitable for precise grinding.
Resinoid bond B Very strong bonding strength, high   safety, suitable for high speed rogh grinding.
Rubber bond R Suitable for the adjusting wheels of   centerless grinding, and cutting wheels

 

Speed:

Operators must respect the maximum operating speed. Never let grinding wheels work over the maximum speed! It is extremely dangerous when you exceed the maximum speed!!!  Rotation generate high strength of centrifugal force. If you rotate over the speed limit, the grinding wheel might be broken by the centrifugal force.  And workers might be severely injured by the chips of broken grinding wheel!

 

 

 

 

 


Post time: Apr-17-2018
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