GB2136011A - Grinding wheel containing cubic boron nitride - Google Patents
Grinding wheel containing cubic boron nitride Download PDFInfo
- Publication number
- GB2136011A GB2136011A GB08403567A GB8403567A GB2136011A GB 2136011 A GB2136011 A GB 2136011A GB 08403567 A GB08403567 A GB 08403567A GB 8403567 A GB8403567 A GB 8403567A GB 2136011 A GB2136011 A GB 2136011A
- Authority
- GB
- United Kingdom
- Prior art keywords
- grinding wheel
- boron nitride
- resin
- cubic boron
- wheel according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 229910052582 BN Inorganic materials 0.000 title claims abstract description 12
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 title claims abstract description 12
- 229920005989 resin Polymers 0.000 claims abstract description 12
- 239000011347 resin Substances 0.000 claims abstract description 12
- 239000000945 filler Substances 0.000 claims abstract description 11
- 229910052709 silver Inorganic materials 0.000 claims abstract description 11
- 239000004332 silver Substances 0.000 claims abstract description 10
- 239000000314 lubricant Substances 0.000 claims abstract description 9
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910052982 molybdenum disulfide Inorganic materials 0.000 claims abstract description 7
- 150000004673 fluoride salts Chemical class 0.000 claims abstract description 6
- 229910052961 molybdenite Inorganic materials 0.000 claims abstract description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical group [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 4
- 239000010439 graphite Substances 0.000 claims abstract description 4
- 229910052759 nickel Inorganic materials 0.000 claims abstract 2
- 229920000642 polymer Polymers 0.000 claims description 2
- 239000004215 Carbon black (E152) Substances 0.000 claims 1
- 229930195733 hydrocarbon Natural products 0.000 claims 1
- 150000002430 hydrocarbons Chemical class 0.000 claims 1
- 150000003839 salts Chemical class 0.000 claims 1
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 abstract description 3
- 239000005011 phenolic resin Substances 0.000 abstract description 3
- 229920001568 phenolic resin Polymers 0.000 abstract description 3
- 239000004952 Polyamide Substances 0.000 abstract description 2
- 229920002647 polyamide Polymers 0.000 abstract description 2
- 229920002313 fluoropolymer Polymers 0.000 abstract 1
- 229910003460 diamond Inorganic materials 0.000 description 10
- 239000010432 diamond Substances 0.000 description 10
- 239000000843 powder Substances 0.000 description 6
- 239000003082 abrasive agent Substances 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- -1 ferrous metals Chemical class 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000011162 core material Substances 0.000 description 2
- HYBBIBNJHNGZAN-UHFFFAOYSA-N furfural Chemical compound O=CC1=CC=CO1 HYBBIBNJHNGZAN-UHFFFAOYSA-N 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 2
- 239000004810 polytetrafluoroethylene Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- 229910020261 KBF4 Inorganic materials 0.000 description 1
- 229910001311 M2 high speed steel Inorganic materials 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 239000005083 Zinc sulfide Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910001634 calcium fluoride Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 229910001610 cryolite Inorganic materials 0.000 description 1
- 239000003085 diluting agent Substances 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 229910052976 metal sulfide Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 235000013824 polyphenols Nutrition 0.000 description 1
- 239000012255 powdered metal Substances 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
- 229910052984 zinc sulfide Inorganic materials 0.000 description 1
- DRDVZXDWVBGGMH-UHFFFAOYSA-N zinc;sulfide Chemical compound [S-2].[Zn+2] DRDVZXDWVBGGMH-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
- B24D3/34—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties
- B24D3/342—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties incorporated in the bonding agent
- B24D3/344—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents characterised by additives enhancing special physical properties, e.g. wear resistance, electric conductivity, self-cleaning properties incorporated in the bonding agent the bonding agent being organic
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
- C08K3/013—Fillers, pigments or reinforcing additives
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/38—Boron-containing compounds
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Polishing Bodies And Polishing Tools (AREA)
Abstract
A resin bonded cubic boron nitride wheel in which the resin bond contains by volume 15-35% of a fluoride salt grinding aid, 0-16% of a dry film lubricant filler and 5 to 40% silver, the resin content of the bond being at least 30% by volume. Up to 50% of the silver may be substituted by nickel. The resin may be a phenolic resin or a polyamide. The dry film lubricant filler may be MoS2, hexagonal boron nitride, graphite or a fluorinated polymer.
Description
SPECIFICATION
Grinding wheel containing cubic boron nitride
This invention relates to resin bonded grinding
wheels containing cubic boron nitride abrasive parti
cles.
The development of diamond grinding wheels
began in the 1930's, and, until the late 1960's, diamond wasthe sole "super" abrasive, much harderthan the conventional aluminum oxide and silicon carbide abrasives. Concurrent with the development of synth eticdiamond by the high pressure-high temperature
method taught in General Electric patents issued in the 1960's, the high density cubic form of boron nitride (CBN) having a hardness similar two diamond was discovered, by applying high pressure to hexagonal boron nitride at high temperature and in the presence of a catalyst, as disclosed in U.S. Patent 2,947,617.
While not superior to diamond in the grinding of carbides (e.g. cemented tungsten carbide) cubic boron nitride (CBN) has been found to be superiorto diamond when ferrous metals, particularlytoolsteels are being ground. Thus CBN wheels can be superior to diamond wheels in the grinding oftools which combine hard carbides and steels.
British Patent 834,351, published in 1960 teaches the use of metal sulfides together with alkali-metal salts such as sulfates as fillers in conventional abrasive wheels for grinding alloy steels. While the patent refers to abrasives generally, and lists diamond, such fillers, so far as is known, have never been commercially employed in diamond wheels or in
CBN wheels.
German Patent P2230701, to Winter & Sohn discloses employing zinc sulfide with cryolite as a grinding aid in stickform to be applied to the workpiece. No suggestion of incorporating the grinding aids in the wheel bond appears in the patent.
Copending U. S. Application S.N. 06/245,855, filed March 1982, discloses the use of grinding aids such as fluorides in a CBN resinoid wheel togetherwith a solid lubricant.
U. S. Patent 3,779,727 issued December 1973, to Sioui and Carver, discloses the use of a metal powder such as silver, togetherwith a dry film lubricant in diamond or in CBN wheels.
U. S. Patent 3,820,290, directed to a particular resin bond and a method of curing it, includes a broad disclosure offillers and abrasives, the fillers including fluoride salts and other grinding aids and the abrasives including CBN and diamond.
The present invention resides in the discoverythat the use of a particular combination of known prior art additives orfillers in a grinding wheel containing CBN abrasive grits results in unpredictably high grinding performance in terms of the ratio ofthe volume of work removed to the volume of wheel wear (G-ratio), and in very low power requirements compared to priorartwheels. The invention requires the presence of a powdered metal filler, particularly silver, a grinding aid, particularly a fluoride salt, and preferably a dryfilm lubricant powder, particularly molybdenum disulfide.
A preferred bond composition of phenolic resin, metal filler, grinding aid, and dryfilm lubricant, in terms of volume % of each ingredient is as follows:
Material Volume %
KAIF4 powder 25
Ag powder 20
MoS2 powder 10
Phenolic resin (a novalac
including 2.0 volume % of lime
based on total bond volume) 45
Nickel powder may be used to substitute for up to 50% of the silver; other fluorides which can be used are KAl3F6, Na3AIF6, KBF4, and CaF2; other solid lubricants are hexagonal boron nitride, graphite, and polytetrafluoroethylene (powder) orotherfluorocarbon polymers.
The "normal" amount of abrasive to include in wheels containing CBN is 25% by volume of the bond plus abrasive (called 100 concentration). As little as 10% and as much as 50% may be used in special circumstances. Diluent abrasives can be employed to a limited extent.
The wheels can befabricated from the above ingredients by wetting the abrasive with furfural and blending it with the mixture of bond and fillers.
Sufficient of the mix is then placed in a mold of the desired shape and hot pressed to form. The tool may then be removed from the mold and the cure completed in an oven. Various conventional shapes of wheels such as cup wheels or cylindrical (raj) wheels may be formed by cementing or otherwise attaching the abrasive shape to a suitable core or center. Typical molding conditions are a pressure of 5 tons per square inch, a temperature of 1 600C, and a molding time of 20 minutes. The final cure can be carried out in an air atmosphere oven for 24 hours at 175 C, as is known in the art, the time and temperature of cure being effective to control the grade or hardness of the wheel depending upon the specific application.
Otherthermally stable resins than phenolics, such as polyamide may be employed with appropriate changes in the processing conditions.
A series of mixes were prepared containing various levels of silver and fillers.
Using standard core materials each mixture was fabricated into several 11 V9 shape cup wheels, 3-3/4" by 1-112" by 1-114" with a rim thickness of 1/16".
The wheels were then tested under the following conditions:
Machine: Norton 6 x 18S-3 Surface Grinder Spindle Speed: 3600 r.p.m.
Table Traverse: 100 inches per minute
Unit Infeed: 3.0 mils, 5 mils, and 7 mils.
Total Infeed: 45 mils
Material Ground: M2 Steel surfaces 1/4"x 1/2"
As a result of the testing of over 50 different mixes thefollowing equations for G-ratio (material removed, divided by wheel wear in volume units) and power in watts were computer generated four a nominal CBN content of 18.75 volume %; where:AG=volume % silver, MO=volume % MoS2, KA=volume % KAIF4, and 1N=infeed in mils:
G = 116.49 + 0.271 (AG) + 0.06404 (AG)(MO)
+ 0.04095 (AG)(KA) - 37.384 (IN)
+ 2.420 (IN)2 - 0.0346 (to)2 P = 675.33 - 22.67 (MO) - 19.35 (KA)
+ 0.3909 (KA)2 + 0.7076 (AG)(MO)
+ 74.44 (IN)
From these results, and other considerations, the following broad and preferred limits were derived:
Broad Limits Preferred
MoS2 0-16% 8-16% KAIF4 15-35% 20-30%
Ag 5-40% 10-30%
Resin 30-50% 40-50%
The preferred composition, listed above, gave the following results, where G is the volume ratio of metal removed to wheel wear.
3 Mil Infeed 5 Mil Infeed
G Power-Watts G Power-Watts
77.4 600 27.7 825 Priorartwheels, one containing silver and polytetrafluoroethylene in optimum amounts, as taught by U.S. Patent 3,779,727, designated wheel "A", and one containing active fillers and graphite, in optimum amounts, designated wheel "B" performed as follows:
3 Mil Infeed 5 Mil Infeed
G Power-Watts G Power-Watts
Wheel A 36 600 3 1,000
Wheel B 35 500 5 650
Claims (7)
1. A resin bonded grinding wheel containing cubic
boron nitride abrasive grits in which the resin bond contains byvolume 15to 35% of a fluoride salt
grinding aid, Oto 16% of a dryfilm lubricant filler, and Sto 40% of silver, the resin content ofthe bond being
atleast30% byvolume.
2. A grinding wheel according to claim 1, in which
a minor portion ofthe silver is substituted by nickel.
3. A grinding wheel according to claim 1 or 2, in
which thefluoride salt is KAIF4.
4. A grinding wheel according to any one of the
preceding claims, in which the dry film lubricantfiller is MoS2, graphite, hexagonal boron nitride, ora
fluorinated hydrocarbon polymer.
5. A grinding wheel according to claim 4, in which
thedryfilm lubricant is MoS2.
6. A grinding wheel according to claim 5, in which
thedryfilm lubricantfillercontentis8to 16%.
7. A resin bonded grinding wheel containing cubic
boron nitride abrasive grits substantially as herein
described with reference to the Example.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US46623183A | 1983-02-14 | 1983-02-14 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8403567D0 GB8403567D0 (en) | 1984-03-14 |
| GB2136011A true GB2136011A (en) | 1984-09-12 |
| GB2136011B GB2136011B (en) | 1986-07-09 |
Family
ID=23850989
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08403567A Expired GB2136011B (en) | 1983-02-14 | 1984-02-10 | Grinding wheel containing cubic boron nitride |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH0669670B2 (en) |
| DE (1) | DE3404851A1 (en) |
| FR (1) | FR2540770B1 (en) |
| GB (1) | GB2136011B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0433031A1 (en) * | 1989-12-11 | 1991-06-19 | Minnesota Mining And Manufacturing Company | Abrasive elements |
| US5562745A (en) * | 1994-03-16 | 1996-10-08 | Minnesota Mining And Manufacturing Company | Abrasive articles, methods of making abrasive articles, and methods of using abrasive articles |
| US6121143A (en) * | 1997-09-19 | 2000-09-19 | 3M Innovative Properties Company | Abrasive articles comprising a fluorochemical agent for wafer surface modification |
| CN100482418C (en) * | 2007-09-20 | 2009-04-29 | 武汉法山磨料磨具有限公司 | Resin abrasive wheel containing teflon dry-grinding lubricant agent and manufacturing method thereof |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0790468B2 (en) * | 1991-08-09 | 1995-10-04 | 株式会社利根 | Cutter for cutting castings |
| CN102059659A (en) * | 2009-11-13 | 2011-05-18 | 沈阳中科超硬磨具磨削研究所 | Formula system for abrasive layer of resin cubic boron nitride (CBN) end face grinding wheel |
| CN104308755B (en) * | 2014-10-21 | 2016-09-21 | 苏州赛力精密工具有限公司 | A kind of resin CBN emery wheel for precessing saw sheet matrix |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3113006A (en) * | 1961-01-30 | 1963-12-03 | Cincinnati Milling Machine Co | Filler for grinding wheels |
| ES393951A1 (en) * | 1970-08-07 | 1974-07-01 | Norton Co | Resin bonded abrasive products |
| US3779727A (en) * | 1971-07-19 | 1973-12-18 | Norton Co | Resin-bonded abrasive tools with metal fillers |
| US3868232A (en) * | 1971-07-19 | 1975-02-25 | Norton Co | Resin-bonded abrasive tools with molybdenum metal filler and molybdenum disulfide lubricant |
| JPS5139398A (en) * | 1974-09-30 | 1976-04-01 | Hitachi Ltd | TORICHIUM UNOCHOZOHOHO |
| GB1472044A (en) * | 1975-08-27 | 1977-04-27 | Inst Material Akad Nauk Ukrain | Composition for manufacturing abrasive tools |
| JPS54106990A (en) * | 1978-02-08 | 1979-08-22 | Mitsui Kensaku Toishi Kk | Resinoid grind stone |
| FR2456769A1 (en) * | 1979-05-16 | 1980-12-12 | Inst Prirodnykh Almazov I | Grinding tool compsn. contg. inorganic salt binder - and also contg. organic binder, abrasive, metal filler and pref. anti-friction agent |
| CA1188103A (en) * | 1981-03-20 | 1985-06-04 | Richard H. Sioui | Cbn grinding wheel |
| JPS5949861B2 (en) * | 1981-03-26 | 1984-12-05 | 本田技研工業株式会社 | Dust collector in machine tools |
-
1984
- 1984-01-27 FR FR8401244A patent/FR2540770B1/en not_active Expired
- 1984-02-07 JP JP59019520A patent/JPH0669670B2/en not_active Expired - Lifetime
- 1984-02-10 GB GB08403567A patent/GB2136011B/en not_active Expired
- 1984-02-10 DE DE19843404851 patent/DE3404851A1/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0433031A1 (en) * | 1989-12-11 | 1991-06-19 | Minnesota Mining And Manufacturing Company | Abrasive elements |
| US5164265A (en) * | 1989-12-11 | 1992-11-17 | Minnesota Mining And Manufacturing Company | Abrasive elements |
| US5562745A (en) * | 1994-03-16 | 1996-10-08 | Minnesota Mining And Manufacturing Company | Abrasive articles, methods of making abrasive articles, and methods of using abrasive articles |
| US6121143A (en) * | 1997-09-19 | 2000-09-19 | 3M Innovative Properties Company | Abrasive articles comprising a fluorochemical agent for wafer surface modification |
| CN100482418C (en) * | 2007-09-20 | 2009-04-29 | 武汉法山磨料磨具有限公司 | Resin abrasive wheel containing teflon dry-grinding lubricant agent and manufacturing method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3404851A1 (en) | 1984-08-16 |
| FR2540770A1 (en) | 1984-08-17 |
| JPH0669670B2 (en) | 1994-09-07 |
| GB8403567D0 (en) | 1984-03-14 |
| GB2136011B (en) | 1986-07-09 |
| JPS59152066A (en) | 1984-08-30 |
| FR2540770B1 (en) | 1987-12-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4378233A (en) | Metal bonded grinding wheel containing diamond or CBN abrasive | |
| CA1129216A (en) | Abrasive bodies of low abrasive high filler content | |
| US4800685A (en) | Alumina bonded abrasive for cast iron | |
| CA2272258C (en) | Abrasive tool | |
| EP0482412B1 (en) | Abrasive product and method of its use | |
| US5846269A (en) | Wear resistant bond for an abrasive tool | |
| US4475926A (en) | Active filler for grinding wheels | |
| JPS5882678A (en) | Coarse tissue organic matter coupled grinding body | |
| US5152810A (en) | Bonded abrasive tools with combination of finely microcrystalline aluminous abrasive and a superabrasive | |
| US4042347A (en) | Method of making a resin-metal composite grinding wheel | |
| US10946499B2 (en) | Bonded abrasive article and method of grinding | |
| US9278431B2 (en) | Bonded abrasive article and method of grinding | |
| US9266219B2 (en) | Bonded abrasive article and method of grinding | |
| GB2136011A (en) | Grinding wheel containing cubic boron nitride | |
| US3899307A (en) | Resin bonded diamond wheels with copper and silicon carbide fillers | |
| US4883501A (en) | Alumina bonded abrasive for cast iron | |
| US2162600A (en) | Filler for abrasive articles | |
| US4988370A (en) | Alumina bonded abrasive for cast iron | |
| JPS6359827B2 (en) | ||
| CA1188103A (en) | Cbn grinding wheel | |
| EP0239918B1 (en) | Grinding wheel | |
| JP2003205466A (en) | Super abrasive wheel and method of manufacturing the same | |
| SU933431A1 (en) | Composition for producing abrasive tool | |
| JP2002292571A (en) | Super abrasive wheel and method of manufacturing the same | |
| GB1584411A (en) | Abrasive-coated sharpening tool |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PE20 | Patent expired after termination of 20 years |
Effective date: 20040209 |