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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 6406-1996 Super abrasive - Grain Sizes of Diamond or Cubic Boron Nitride, and the following main technical changes have been made with respect to GB/T 6406-1996:
——In the "Application Scope", "for manufacturing grinding wheel, saw and other industrial products" is deleted, and "(41μm~1,180μm)" is modified to "16/18~500/600" (see Chapter 1; Chapter 1 in 1996 edition);
——Normative references are modified (see Chapter 2; Chapter 2 of 1996 edition);
——Grain size designation is modified, and 500/600 and 35/45 are added (see Tables 3 and 4; Table 1 in 1996 edition);
——The requirements for timer are modified (see 3.4; 4.5 in 1996 edition);
——Requirements for test environment conditions are modified (see Chapter 4; 5.1 in 1996 edition);
——Requirements for varieties of test sieves are modified, and only electroformed sieves can be used (see 3.2; 4.2 in 1996 edition);
——Requirements for aperture size deviation of test sieves are modified (see Table 2; 4.2.2 in 1996 edition);
——Requirements for ruling line deviation of test sieves are added (see 3.2);
——The undersize limiting sieves for grain size designations 270/325 and 325/400 are added (see Table 3);
——Requirements for grain size composition are modified (see Tables 3 and 4; Table 1 in 1996 edition);
This standard has been redrafted and modified in relation to ISO 6106:2013 Abrasive Products - Checking the Grain Size of Superabrasives.
The technical changes with respect to ISO 6106:2013 and the corresponding reasons are as follows:
——JB/T 3914 Superabrasive - Sampling Method and GB/T 18845 Abrasive Grains - Test-sieving Machines are added in "Normative References" in order to adapt to the technical conditions of China;
——The normative reference "ISO 554 Standard Atmospheres for Conditioning and/or Testing – Specifications" is deleted as its relevant provisions have been described in details in this standard;
——Requirements for aperture size deviation and ruling line deviation of test sieves are added to improve the enforceability of this standard;
——The grain size designation method is modified and equivalent sieve size designation method is adopted to adapt to the habits of China;
——The ruling line requirements of electroformed sieves with aperture sizes of 1,010μm, 25μm and 20μm are added; the ruling line requirements of electroformed sieves with aperture sizes of 32μm and 28μm are modified to ensure integrity and rationality of this standard;
——"8.1 General" is deleted as it is repeated with the content of 8.2 (see 8.1 and 8.2 in ISO 6106:2013);
——Notes in Tables 2 and 3 are deleted (see Tables 2 and 3 in ISO 6106:2013); thereinto, the particle size distribution is inoperable; other contents have been clearly described in this standard, so they are not noted repeatedly.
There have been many structural adjustments in this standard with respect to ISO 6106:2013, and the comparison of chapter and article numbers between this standard and ISO 6106:2013 is given in Annex A herein.
To be convenient for use, this standard also covers the following editorial changes to ISO 6106:2013:
——The standard name is modified.
This standard was proposed by China Machinery Industry Federation.
This standard is under the jurisdiction of the National Technical Committee on Abrasive and Grinding Machine of the Standardization Administration of China (SAC/TC 139).
The previous editions of this standard are as follows:
——GB/T 6406.1-1986;
——GB/T 6406.2-1986;
——GB/T 6406-1996.
Superabrasive - Checking the Grain Size
1 Scope
This standard specifies test apparatus, test conditions, test methods, result evaluation, grain size designation and grading limits for checking the grain size of superabrasive without any plating.
This standard is applicable to checking the grain size of 16/18~500/600 artificial diamond or cubic boron nitride.
2 Normative References
The following documents for the application of this document are essential. Any dated reference, just dated edition applies to this document. For undated references, the latest edition (including any amendments) applies to this document.
GB/T 18845 Abrasive Grains - Test-sieving Machines
JB/T 3914 Superabrasive - Sampling Method
3 Test Apparatus
3.1 Test-sieving machine
The test shall be carried out with the test-sieving machines meeting those specified in GB/T 18845.
3.2 Test sieves
3.2.1 Category
The electroformed sieves with square apertures shall be used.
3.2.2 Requirements
The test sieves shall meet the following requirements:
a) The test sieves shall have a supporting grid of 2.2 lines per centimetre bonded to the top surface and shall also have a 200mm or 75mm diameter stainless frame with height of 25mm.
b) A receiver pan and a lid are required for the stack of sieves.
c) The aperture sizes and ruling lines of test sieves shall be in accordance with Table 1, the deviation of aperture sizes shall be in accordance with Table 2 and that of ruling lines shall not be larger than 5% of the values specified in Table 1.
d) The test sieves shall be cleaned periodically by ultrasonic methods.
Table 1 Aperture Sizes and Ruling Lines of Test Sieves
Aperture size
μm Ruling line
cm-1 Aperture size
μm Ruling line
cm-1
1,830 4.97 1,080 7.9
1,520 5.8 1,010 8.2
1,280 6.5 915 8.5
850 9.2 165 39.4
770 10.9 151 43.7
710 11.8 139 46.3
645 12.2 127 49.2
600 13.4 116 49.2
541 15.0 107 59.1
505 15.7 97 65.6
455 16.4 90 65.6
425 17.9 85 71.6
384 18.7 75 78.7
360 20.3 65 78.7
322 21.9 57 87.5
302 24.6 49 98.4
271 26.2 41 98.4
255 26.2 32 125
227 30.3 28 150
213 30.3 25 150
197 35.8 20 200
181 35.8 — —
Table 2 Aperture Size Deviation Requirements of Test Sieves
Aperture size range
μm Aperture size deviation requirement (quantity percentage)
X≤2μm 2μm5μm
≤97 100% 0 0 0 0
127~197 ≥80% <20% 0 0 0
213~455 ≥70% <30% <5% 0 0
505~915 ≥60% <40% <10% 0 0
1,080~1,830 ≥50% <50% <15% <5% 0
X is the absolute value of the difference between measured value and nominal value of single aperture size.
3.3 Balance
A laboratory balance shall be used which has a division value of not greater than 0.01g if using φ200mm sieves or not greater than 0.001g if using φ75mm sieves.
3.4 Timer
A timer with an accuracy of ±1% in 15min shall be used.
4 Test Conditions
The test shall be performed under the following conditions:
——Temperature: (23±2)℃;
——Relative humidity: (50±5)%.
5 Test Methods
5.1 Sampling
The material under test shall be blended and the sample shall be taken out utilizing the method specified in JB/T 3914. Then the sample shall be placed on a stainless steel pan and kept still for 30min.
The mass of the sample shall fall within the required range indicated in Tables 3 and 4.
5.2 Preparation for sieving
Assemble the desired stack of sieves (3.2) in the order of aperture sizes, with a receiver pan on the bottom. Pour the test sample on to the top sieve and place a lid over it. Place the entire unit into the test-sieving machine (3.1). The sieve stack shall be free to rotate during the sieving cycle. To facilitate rotation, ensure that the head yoke of the machine and the bottom plate adaptor do not seize up the sieve stack.
Special adaptors for φ75mm sieves are specified in Annex B.
Foreword I
1 Scope
2 Normative References
3 Test Apparatus
4 Test Conditions
5 Test Methods
6 Result Evaluation
7 Grain Size Designation and Grading Limits
8 Example Showing the Use of Table
Annex A (Informative) Structural Changes of This Standard with Respect to ISO 6106:
Annex B (Normative) Special Adaptors for φ75mm Sieves
