Grinding Machine Tooling

▸How dimensions are written

Conventional wheels

In the order outside diameter (D) × thickness (T) × bore (H) mm. E.g. 305×25×76.2, 205×19×25.4^[1][2][3]Types other than No. 1 and No. 2 need detailed dimensions or a drawing (Noritake)

Superabrasive wheels

Outside diameter × thickness × bore, plus the abrasive layer thickness (e.g. 200×15×50.8×3)^[3][4]

Standard

—Not confirmed in public sourcesThe text and abstracts of JIS R 6211 and ISO 525 could not be retrieved from JSA and ISO, so they were not confirmed. Values are from manufacturer documents

▸Shape numbers

▸Superabrasive wheel shapes

▸Edge profiles

▸Conventional wheel marking

Order

Abrasive, grit size, grade, structure, bond, sub-symbol (manufacturer's own), maximum operating speed^[1][2][3]

Examples (by manufacturer)

• No. 1 305×25×76.2 WA 60 K 7 V 33m/s^[1]
• No. 1 A 205×19×25.4 WA 60 K 7 V 1 33m/s^[2]
• 305×32×127 32A 60 K 8 V** 1 A^[3]

How to read the example

WA60K8V = white alumina abrasive, grit 60, grade K, structure 8, vitrified bond^[1][3]

Abrasive

• Noritake:PA, SA, CX (A series)^[1]
• Kuretoishi:RA pink alumina, 32A friable alumina, SG microcrystalline alumina, ZG alumina-zirconia^[3]

Grit size

• Rule The smaller the number, the coarser; the larger, the finer^[1][2][3]
• Range (by manufacturer)
  • F8–F220 (coarse grit, F designation), #240–#8000 (fine grit, # designation). JIS classifies sizes 8–3000^[1]
  • 8 (coarse) to 3,000 (fine)^[3]
• Usage notes Up to about F36 is used for offhand grinding (deburring, cutting off); finer than F46 is mainly used for machine grinding^[1]1 source · reference

Grade (hardness)

Letters A (soft) to Z (hard)^[1][2][3]

Structure

• Rule Expresses the abrasive volume as a number; the smaller the number, the denser (more abrasive grain), the larger, the more open^[1][2][3]
• Range (by manufacturer)
  • 1 (dense) to 14 (open)^[3]

Structure is not marked on offset wheels (New Resiston)

Bond

• Noritake:M = metal, P = electroplated^[1]
• Kuretoishi:E = shellac, SS = oxychloride. Symbols after the initial letter are the maker's own bond symbols^[3]
• New Resiston:BF = reinforced resinoid (example of an offset wheel)^[2]

Sub-symbol

The variation symbol after the bond is manufacturer-specific^[2][3]

▸Superabrasive wheel marking

Order

Abrasive, grit size, grade, concentration, bond^[3][4]

Examples (by manufacturer)

• SDC 200 N 100 BDH 3.0 (the last is abrasive layer thickness in mm)^[4]
• 200×15×50.8×3 B 80 H 200 V** 1A1 (B = CBN; the final 1A1 is the shape type)^[3]

Abrasive (by manufacturer)

• SD synthetic diamond, ASD synthetic diamond (metal-coated), B or CBN = CBN, CB = CBN (metal-coated)^[3]
• SDC = metal-coated diamond^[4]

Grade (by manufacturer)

• A (soft) to R (hard)^[3]

Concentration

Concentration 100 = 25 vol% abrasive (concentration ÷ 4 = abrasive volume %)^[5]1 source · reference

Concentration (by manufacturer)

• Marking examples from 125 (low) to 200 (high)^[3]

Bond (by manufacturer)

• V vitrified, B resin, M metal, MKSL metal single layer, EP electroplated^[3]
• V, B, M and P (electroplated) apply to CBN and diamond^[1]

JIS notes

In JIS the symbol for resin bond is B, but manufacturers often mark their own bond names (e.g. BDH)^[4]1 source · reference

Definition

JIS B 4131 calls a tool with an abrasive layer mainly on the periphery or face of a metal core a "wheel", to distinguish it from the grinding wheels of JIS R 6210 and R 6212^[6]1 source · reference

Definition of concentration 100

—Not confirmed in public sources"4.4 ct/cm³ = concentration 100" appeared in a search-result snippet but could not be confirmed in the body text of the manufacturer documents retrieved

▸Flanges

General

When mounting a grinding wheel on a grinding machine, use flanges that conform to the structural standard (ring-type and disc-type backing plates, wheels with nuts, segments, mounted wheels, flat wheels for precision internal grinding, etc. may use other mounting fixtures)^[7]1 source · reference

Material

Made of material with tensile strength equal to or greater than gray cast iron (Class 2 of JIS G 5501-1956), and must not deform^[7]1 source · reference

Same dimensions on both sides

Fixed-side and movable-side flanges must have equal diameter and contact width^[7][8][1]

Fixed side

The fixed-side flange is secured to the wheel spindle by key, screw, shrink fit, press fit, etc., and the tightening screw must tighten in the direction of rotation^[7]1 source · reference

Straight flange

• Diameter At least 1/3 of the grinding wheel diameter^[7][9]
• Relief Relief of 1.5 mm or more^[7][9]
• Contact width
  • D≦65 More than 0.1Df and less than 0.26Df
  • 65<D≦355 More than 0.08Df and less than 0.18Df
  • D>355 More than 0.06Df and less than 0.18Df
  ^[7]1 source · referenceD = wheel diameter, Df = flange diameter
• Reinforced cut-off wheel For reinforced cut-off wheels with a maximum operating speed of 80 m/s or less (reinforced for a cutting load of 700 N or more), 1/4 or more is acceptable^[7][9]Kuretoishi gives the same content in old units (4,800 m per minute, 71 kg)

Sleeve / adapter flange

• Type Df ≥ κ(D − H) + H (H = pilot diameter of the flange)^[7][9]
• Approach angle
  • D<610
    • Normal 0.13
    • High-speed 0.15
  • 610≦D<760
    • Normal 0.11
    • High-speed 0.13
  • 760≦D<1065
    • Normal 0.1
    • High-speed 0.12
  • D≧1065
    • Normal 0.08
    • High-speed 0.1
  ^[7]1 source · referencenormal = normal speed, highSpeed = other than normal speed
• Adapter limit Adapter flanges must not be used for wheels other than normal speed (high speed)^[7][9]

Safety flange

• Straight wheel At least 2/3 of the wheel diameter
• Double taper At least 1/2
• Relief At least 1.5 mm
• Contact width At least 1/6 of the flange diameter
• Taper contact For double-bevel wheels, a slope of at least 1/16 on the contact surface

^[7]1 source · reference

Blotter

Use wheel blotters (paper packing) larger than the flange diameter. For safety flanges for straight wheels, use rubber blotters^[7][1][8]

▸Maximum operating speed

Definition

The upper limit of peripheral speed (m/s) at which the wheel can be used safely. It must not be exceeded^{[10][1][9][2]}

Normal operating speed limit (m/s)

• Item
  • • Grinding wheel Straight wheel (unreinforced, general purpose)
    • Inorganic 33
    • Organic 50
  • • Grinding wheel Straight wheel (unreinforced, for heavy-duty grinding)
    • Inorganic —
    • Organic 63
  • • Grinding wheel Straight wheel (for thread and groove grinding)
    • Inorganic 63
    • Organic 63
  • • Grinding wheel Straight wheel (for crankshaft and camshaft grinding)
    • Inorganic 45
    • Organic 50
  • • Grinding wheel Straight wheel (reinforced, D≤100 and T≤25)
    • Inorganic —
    • Organic 80
  • • Grinding wheel Straight wheel (reinforced, 100<D≤205 and T≤13)
    • Inorganic —
    • Organic 72
  • • Grinding wheel Single-bevel, double-bevel, recessed one side, recessed two sides, safety, dish, saucer (saw sharpening)
    • Inorganic 33
    • Organic 50
  • • Grinding wheel Cylinder (ring) wheel
    • Inorganic 30
    • Organic 35
  • • Grinding wheel Straight cup, flaring cup
    • Inorganic 30
    • Organic 40
  • • Grinding wheel Disc type (Jisuku)
    • Inorganic 33
    • Organic 45
  • • Grinding wheel Offset (depressed-center) type (D≤230, T≤10; unreinforced / reinforced)
    • Inorganic —
    • Organic 57/72
  • • Grinding wheel Cut-off wheels (unreinforced / reinforced)
    • Inorganic —
    • Organic 63/80
  ^[7][1][9]

Table "Limits of normal operating peripheral speed" of the Structural Standard for Grinding Machines. Inorganic = vitrified, etc.; organic = resinoid, etc.

Conversion for imported wheels

• 8500 45
• 9500 50
• 12000 60
• 16000 80
• 20000 100
• 6500 ft/min 33

^[7]1 source · referenceConversion of imported wheels' feet per minute to m/s

Size limits by operating speed

• Other than normal speed, up to 45 m/s (straight wheels, etc.) D≤1065, bore H≤0.6D
• 45〜60 m/s D≦1065、H≦0.5D
• 60–80 m/s (straight, offset, cut-off wheels, etc.) D≤760 (1500 for cut-off), H≤0.33D
• 80〜100 m/s D≤760 (1500 for cut-off), H≤0.2D
• Normal speed H≦0.7D

^[7][9]Only the main values from the table in Article 14 of the structural standard. For conditions such as thickness, see the text of the notice

Spin test

Wheels of 100 mm diameter or more are spin-tested at 1.5 times the maximum operating speed for each lot^[7]1 source · reference

Color bands (by manufacturer)

• Color bands on high-speed wheels: up to 45 m/s = blue, 45–60 = yellow, over 60 = red (about 20 mm wide)^[9]

Marking requirements

Wheels must be marked with the manufacturer's name, bond type and maximum operating speed (for diameters under 75 mm, marking per smallest packaging unit is acceptable)^[7]1 source · reference

▸Rules for use

Trial run

Trial run of at least 1 minute before starting work, and at least 3 minutes after changing a wheel^[10][8]

Use of the side face

Do not use the side of a wheel unless it is intended for side use^[10][9]

Wheel guard

Provide a guard when a rotating wheel may be hazardous (except diameters under 50 mm)^[10]1 source · reference

Work rest

On bench and pedestal grinders, the gap between the work rest and the wheel periphery must be adjustable to 3 mm or less, and the gap between the guard and the periphery to 10 mm or less^[7]1 source · reference

Usage limits (by manufacturer)

• Guide to the wear limit: for straight wheels, down to 1/10 of the portion protruding from the flange; for recessed wheels, down to 1/5 of the portion excluding the recess^[9]

Bore tolerance (by manufacturer)

• Bore tolerance for machine grinding: 1.6≤H≤50: +0.16/0, 50<H≤80: +0.19/0, 80<H≤180: +0.25/0 … (when the shaft side is f7 or better)^[9]

▸Machine-side mounting

Wheel bore diameter by machine

• ⌀180〜255×8〜19×⌀50.8^[11]
• ⌀200〜355×25〜38×⌀127^[11]

Wheel spindle taper

—Not confirmed in public sourcesNo public source was found that gives wheel spindle end tapers or flange mounting dimensions for surface and cylindrical grinders (probably handled in each model's instruction manual)