Information on our NASTON product 1
Three elementsof grindstone

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A grindstone is made of three elements: stone grains, a bond and pores

Stone grains
The stone grains are an essential element for cutting workpieces. Each grain acts as a cutting edge to cutworkpieces. When grains are abraded and their cutting performance is lost, those grains come off and newones appear. Thanks to this self-regenerative feature, the cutting performance of the grindstone ismaintained until the end of its service life.

BondStone
grain

Grindstone

The bond keeps the stone grains together. There are bonds with various levels of hardness (bondinglevels). The bonding level significantly influences the abrasion level and cutting performance of thegrindstone.

Pores
When cutting the workpieces, chips and heat will be generated through abrasion. To address them,innumerable pores are included in the grindstone. Roughly speaking, the grindstone has a pumice-likestructure. The chips generated through cutting will enter these pores and be expelled when the grindstonerotates. Without pores, a grindstone would immediately stop working because there would be no place toaccommodate the chips. Further, the pores serve to cool down the grindstone by allowing air to go inside
it. Therefore, the pores in a grindstone play very important roles that should not be overlooked.

Bond

Pore

Reading the label
The standardized label description for grindstones is indicated below.
description• Example:100ANB
205 0.8 25.4
Dimensions (outer dia. × thickness × inner dia.)

Stone grain

Grain size

Bonding level

Bond

Peripheral velocity

Stone grain, grain size … coarse to fine grain, bonding level … soft to hard, bond…resinoid

Information on our NASTON product 2

http://www.heiwa-tec.co.jp

Processing with a NASTON
Characteristics
It is a type of precision processing conducted with a grindstone wheel rotating at high speed. A workpiece is cut gradually by extremely hard particles (stonegrains) included in the grindstone. Because it is a cutting process based on abrasion, any damage to the workpiece is kept to a minimum and a very fine finish
can be obtained. This makes the product suitable for precision cutting with its excellent cutting performance.

Mechanism
The numerous grains extruded on the action surface of the grindstone will cut a workpiece gradually. Meanwhile, the extrusion of the grains is also abraded,destroyed and detached from the action surface. After the old grains came off, new ones appear on the action surface one by one.

• The grindstone is made of three essential elements: stone grains, a bond and pores • Basic label description for grindstones
Stone grain

BondPores

A 100 N205

0.825.4

Grain

Outer
diameterThickness

InnerdiameterGrain
size

BondinglevelThere are the following types of grains. It is best to use a grindstone with suitable grain characteristics for your workpiece.
Category

Alumina
type
Stone
grain
Carbide type
Mixed type

SymbolDescription

Characteristics and application

AAlundumBeing manufactured from bauxite, it is suitable for cutting materials with high tensile
strength such as iron or steel due to its toughness (fracture toughness).

WAWhite Alundum

Compared to Type A grain, the abrasion of the cutting edge is slower and a sharp edge appears quicker.
Because the entire resistance against workpieces is lower, less heat is generated than with Type A grain.
Depending on the properties of a workpiece, Type WA may have a better performance than Type A.

HANA

Heiwa Alundum

Our original grain. Because of its sharp edge and appropriate level of fracture strength
ensuring high grinding performance, it is suitable for ultra-hardened products and such like.

GCGreen Carbolundum

Being mainly manufactured from silica and carbide, it has a low toughness despite its
high hardness. It is suitable for non-metal materials in general.

TCDiamond

It is the hardest type of grain suitable for cut-resistant materials that cannot be cut withother types of grindstones. It tends to be affected by the heat generated during cutting.

ACAlundum and carbolundum

Mixture of Type A and Type GC grains. Suitable for cutting malleable casting ironSelecting Heiwa’s Grindstone Wheels for Precision Cutting[NASTON/NASTON GOLD Series]

General steel materials,
thick and special steel materials

Material
Standard carbon steel (S-C), toolsteel (SK), soft steel (SS), tool alloysteel (SKS), die steel (SKD),hardened spring steel (SUP) etc.

Application: Hardness (comparison of hardness)
Ejector pin for metals, key material, drawing profile,springs, regular pipes, wires
Rockwell hardness (Rc)
Vickers hardness (Hv)complex material,
ultra-hardened material, regular
cast (FC)

Drill rods, hardened products, metals for SEM inspection, machineparts, hardened gauge plates, small bore drills, end mill cutting
Rockwell hardness (Rc)
Vickers hardness (Hv)

Rockwell hardness (Rc)
Vickers hardness (Hv)

Non-ferrous materials, general materials,
complex materials, thin-wall pipes

Approx. 35 to 55
Approx. 345 to 595

Stainless steel, Inconel
magnesium, non-ferrous
material, tungsten, molybdenum,precious metals including goldand silver, titanium, hard rubber,resin, Bakelite, rock, crystal,
quartz, ceramics, hard glass,soda glass, carbon, phenol or
epoxy resin

Approx. 35 to 55
Approx. 345 to 595

Ultra-hardened products made of special steel (SNCM),
high-speed steel (SKH) and stainless steel (SUS) etc.
Rockwell hardness (Rc)
Vickers hardness (Hv)

Approx. 60 to 70
Approx. 697 to 1076

A100N
A100P
31-A
Stainless A
HA80P
HA100J
NA100J
AC100J

Electrical steel, malleable casting iron, aluminum alloy
Rockwell hardness (Rc)
Vickers hardness (Hv)

Hard and brittle materials

Approx. 31 to 50.5
Approx. 310 to 520

SCM, SKD (material with large cross section)

Special alloy, cut-resistant

Wheel Part Number

NA100JB

21.3 or less
255 or less

Precision pipes, medical equipment, golfing gear, electronic parts,
LC panel contacts, car parts, thin-wall pipes, small decorative items,
complex material parts, dental specimens, decorative items made of
hard material, general glass processed items, small decorative items
Rockwell hardness (Rc)
Vickers hardness (Hv)

A100PB

Approx. 21.3 to 40.8
Approx. 70 to 400*Rockwell hardness (Rc): 20 or less, Vickers hardness (Hv): 238 or more.

GC100P
GC100N
GC150N
GC150L
GC150H
GC320R
Stainless B
GC400LWA220R

GC150HB

GC150LB

Super-hard alloys, ceramics,
quartz, crystal, hard glass, ferrite,
carbon, magnetic materials,nickel, molybdenum, tungsten

Cutting tools, car parts, electronic parts, LC panels, aircraft parts,
semiconductor heat sink materials, heat sinks
Rockwell hardness (Rc)
Vickers hardness (Hv)

75 or more
1478 or more

TC-1
TC-2
TC-1