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Subchapter 7. General Industry Safety Orders
Group 3. General Plant Equipment and Special Operations
Article 21. Use, Care, and Protection of Abrasive Wheels

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§3583. Portable Abrasive Wheels.


(a) General requirements. Abrasive wheels shall be used only on machines provided with safety guards as required in Section 3577(b).

(b) A safety guard shall cover the spindle end, nut and flange projections. The safety guard shall be mounted so as to maintain proper alignment with the wheel, and the strength of the fastenings shall exceed the strength of the guard.

Exceptions: (1) Safety guards on all operations where the work provides a suitable measure of protection to the operator may be so constructed that the spindle end, nut and outer flange are exposed. Where the nature of the work is such as to entirely cover the side of the wheel, the side covers of the guard may be omitted. (2) The spindle end, nut, and outer flange may be exposed on portable machines designed for, and used with, Types 6, 11, 27, and 28 abrasive wheels, cutting-off wheels, and tuck pointing wheels.

(c) Cup wheels. Cup wheels (Types 6 and 11) shall be protected by:

 (1) Safety guards as specified in this section; or 


 (2) Special "Revolving Cup Guards" which mount behind the wheel and turn with it. They shall be made of steel or other material with adequate strength and shall enclose the wheel sides upward from the back for one-third of the wheel thickness. The mounting features shall conform with all regulations. (See Section 3580.) It is necessary to maintain clearance between the wheel side and the guard. The clearance shall not exceed one-sixteenth inch; or, 


 (3) Some other form of guard that will insure as good protection as that which would be provided by the guards specified in subsections (a) and (b) of this section. 


(d) Vertical portable grinders. Safety guards used on machines known as right angle head or vertical portable grinders shall have a maximum exposure angle of 180 degrees, and the guard shall be so located so as to be between the operator and the wheel during use. Adjustment of guard shall be such that pieces of an accidentally broken wheel will be deflected away from the operator. (See Figure A-22 of Appendix E.)

(e) Other portable grinders. The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on other portable grinding machines shall not exceed 180 degrees and the top half of the wheel shall be enclosed at all times. (See Figure A-23 of Appendix E.)

(f) Mounting and inspection of abrasive wheels.

 (1) Immediately before mounting, all wheels shall be closely inspected and sounded by the user to make sure they have not been damaged in transit, storage, or otherwise. The spindle speed of the machine shall be checked before mounting of the wheel to be certain that it does not exceed the maximum operating speed marked on the wheel. 


 (2) Grinding wheels shall fit freely on the spindle and remain free under all grinding conditions. A controlled clearance between the wheel hole and the machine spindle (or wheel sleeves or adaptors) is essential to avoid excessive pressure from mounting and spindle expansion. To accomplish this, the machine spindle shall be made to nominal (standard) size plus zero minus .002 inch, and the wheel hole shall be made suitably oversize to assure safety clearance under the conditions of operating heat and pressure. 


 (3) All contact surfaces of wheels, blotters, and flanges shall be flat and free of foreign matter. 


 (4) When a bushing is used in the wheel hole it shall not exceed the width of the wheel and shall not contact the flanges. 


 
TABLE A-1 MINIMUM DIMENSIONS FOR STRAIGHT RELIEVED FLANGES


 
----------------------------------------------------------------               
 A [FNa1]        B                  C                    D              E      
            Minimum          Radial Width of          Minimum        Minimum   
              Outside        Bearing Surface         Thickness    Thickness of 
                         ------------------------                              
Diameter    Diameter of                              of Flange      Flange at  
                                                                      Edge     
of Wheel      Flanges      Minimum      Maximum       at Bore       of Recess  
-------------------------------------------------------------------------------
  Inches      Inches       Inches       Inches         Inches        Inches    
    1 ......... 3/8 ....... 1/16 ........ 1/8 ........  1/16 ........ 1/16     
    2 ......... 3/4 ........ 1/8 ....... 3/16 ........  1/8 ......... 3/33     
    3 .......... 1 ......... 1/8 ....... 3/16 ........  3/16 ........ 3/33     
-------------------------------------------------------------------------------
    4 ........ 1 1/8 ....... 1/8 ....... 3/16 ........  3/16 ......... 1/8     
    5 ........ 1 3/4 ...... 3/16 ........ 1/4 ........  1/4 .......... 1/8     
    6 .......... 2 ......... 1/4 ........ 1/2 ........  3/8 ......... 3/16     
    7 ........ 2 1/2 ....... 1/4 ........ 1/3 ........  3/8 ......... 3/16     
-------------------------------------------------------------------------------
    8 .......... 3 ......... 1/4 ........ 1/2 ........  3/8 ......... 3/16     
    10 ....... 3 1/2 ...... 3/16 ........ 3/8 ........  3/8 .......... 1/4     
    12 ......... 4 ........ 3/16 ........ 3/8 ........  1/3 ......... 3/16     
-------------------------------------------------------------------------------
    14 ....... 4 1/2 ....... 3/8 ........ 3/4 ........  1/2 ......... 3/16     
    16 ....... 5 1/2 ....... 1/2 ......... 1 .........  1/2 ......... 3/16     
    18 ......... 6 ......... 1/2 ......... 1 .........  3/8 .......... 3/8     
-------------------------------------------------------------------------------
    20 ......... 7 ......... 3/8 ....... 1 1/4 .......  3/8 .......... 3/8     
    22 ....... 7 1/2 ....... 3/8 ....... 1 1/4 .......  3/8 ......... 7/16     
    24 ......... 8 ......... 3/4 ....... 1 1/4 .......  3/8 ......... 7/16     
-------------------------------------------------------------------------------
    26 ....... 8 1/2 ....... 3/4 ....... 1 1/4 .......  1/8 .......... 1/2     
    28 ........ 10 ......... 7/8 ....... 1 1/2 .......  3/4 .......... 1/2     
    30 ........ 10 ......... 7/8 ....... 1 1/2 .......  3/4 .......... 3/8     
-------------------------------------------------------------------------------
    36 ........ 12 .......... 1 .......... 2 .........  7/8 .......... 3/4     
-------------------------------------------------------------------------------
    42 ........ 14 .......... 1 .......... 2 .........  7/8 .......... 3/4     
    48 ........ 16 ........ 1 1/4 ........ 2 ........  1 1/8 .......... 1      
    60 ........ 20 ........ 1 1/4 ........ 2 ........  1 1/4 ........ 1 1/8    
    72 ........ 24 ........ 1 1/2 ...... 2 1/2 ......  1 3/8 ........ 1 1/4    
-------------------------------------------------------------------------------
[FNa1] Flanges for wheels under 2 inches diameter may be unrelieved and shall  
  be maintained flat and true.                                                 
 
 

                                 TABLE A-2                                     
            MINIMUM DIMENSIONS FOR STRAIGHT UNRELIEVED FLANGES FOR             
               WHEELS WITH THREADED INSERTS OR PROTJECTING STUDS               

-------------------------------------------------------------------------------
                                 B [FNa1]                         T            
          A                          Minimum Outside      Minimum Thickness    
Diameter of Wheel                 Diameter of Flange          of Flange        
-------------------------------------------------------------------------------
       Inches                     Inches                       Inches          
          1 ....................... 3/8 ........................ 1/8           
          2 ........................ 1 ......................... 1/8           
          3 ........................ 1 ........................ 3/16           
          4 ...................... 1 3/8 ...................... 3/16           
          5 ...................... 1 3/4 ....................... 1/4           
          6 ........................ 2 ......................... 3/8           
[FNNote:] a1 Must be large enough to extend beyond the bushing. Where prong    
  anchor or cupback bushing are used, this footnote does not apply.            
 
 

                                  TABLE A-3                                    
                MINIMUM DIMENSIONS FOR STRAIGHT ADAPTOR FLANGE                 
           --FOR ORGANIC BONDED WHEELS OVER 1 1/4 INCH THICK [FNa1]            
 
-------------------------------------------------------------------------------
                                                          E                    
                               B           D           Minimum          F*     
    Wheel        Wheel      Minimum     Minimum      Thickness of      (D-E)   
  Diameter                                                                     
                  Hole      Flange    Thickness of  Flange at Edge    Minimum  
                Diameter   Diameter    Flange at     of Undercut     Thickness 
                                          Bore                                 
-------------------------------------------------------------------------------
   Inches        Inches     Inches       Inches         Inches        Inches   
     12 .......... 4 ......... 6 ........ 7/8 ..........  3/8 ......... 1/2    
     to .......... 5 ......... 7 ........ 7/8 ..........  3/8 ......... 1/2    
     14 .......... 6 ......... 8 ........ 7/8 ..........  3/8 ......... 1/2    
-------------------------------------------------------------------------------
 Larger than ..... 4 ......... 6 ........ 7/8 ..........  3/8 ......... 1/2    
     14 .......... 5 ......... 7 ........ 7/8 ..........  3/8 ......... 1/2    
     to .......... 6 ......... 8 ........ 7/8 ..........  3/8 ......... 1/2    
     18 .......... 7 ......... 9 ........ 7/8 ..........  3/8 ......... 1/2    
                   8 ........ 10 ........ 7/8 ..........  3/8 ......... 1/2    
-------------------------------------------------------------------------------
 Larger than ..... 6 ......... 8 ......... 1 ...........  1/3 ......... 1/8    
     18 .......... 7 ......... 9 ......... 1 ...........  1/2 ......... 1/2    
     to .......... 8 ........ 10 ......... 1 ...........  1/2 ......... 1/2    
     24 .......... 10 ....... 12 ......... 1 ...........  1/2 ......... 1/2    
                   12 ....... 14 ......... 1 ...........  1/2 ......... 1/2    
-------------------------------------------------------------------------------
Larger than                                                                    
  24 to 30 ....... 12 ....... 15 ......... 1 ........... 1/2 .......... 1/2    
-------------------------------------------------------------------------------
Larger than                                                                    
  30 to 36 ....... 12 ....... 15 ....... 1 3/8 ......... 7/8 .......... 1/2    
-------------------------------------------------------------------------------
[FNa1] For wheels under 1 1/4 inch thick F dimension shall not exceed 40% of   
  wheel thickness.                                                             
 
 

                                 TABLE A-4                                     
            MINIMUM DIMENSIONS FOR STRAIGHT FLANGES--FOR MECHANICAL            
                                 GRINDERS                                      
                   12,500 S.F.P.M. to 16,5000 S.F.P.M. [FN1]                   
 
-------------------------------------------------------------------------------
                                                     'E' Minimum               
                        'B' Minimum    'D' Minimum    Thickness of    F [FNa1] 
                                                                       (D-E)   
  Wheel     Wheel Hole     Flange     Thickness of   Flange at Edge   Minimum  
 Diameter    Diameter     Diameter      Flange at     of Undercut    Thickness 
                                          Bore                                 
-------------------------------------------------------------------------------
    20 ........ 6 .......... 8 ............ 1 ...........  1/2 ........ 1/2    
    20 ........ 8 .......... 10 ......... 1 1/2 .........  3/4 ........ 3/4    
    24 ........ 12 ......... 15 ........... 2 ............  1 .......... 1     
    30 ........ 12 ......... 15 ........... 2 ............  1 .......... 1     
    36 ........ 12 ......... 15 ........... 2 ............  1 .......... 1     
-------------------------------------------------------------------------------
[FN1.]FLANGES shall be of steel, quality SAE 1040 or equivalent, annealed      
  plate, heat treated to R 25-30.                                              
[FNa1] For wheels under 1 1/4 inch thick F dimension shall not exceed 40% of   
  wheel thickness.                                                             
 
 

                                  TABLE A-5                                    
                MINIMUM DIMENSIONS FOR STRAIGHT FLANGES USED AS                
                   WHEEL SLEEVES FOR PRECISION GRINDING ONLY                   
 
-------------------------------------------------------------------------------
                                                                      E        
                                     B               D             Minimum     
                              Minimum Outside     Minimum        Thickness of  
                                                 Thickness                     
                    Wheel       Diameter of      of Flange      Flange at edge 
Wheel Diameter      Hole          Flange          at Bore        of Undercut   
                  Diameter                                                     
-------------------------------------------------------------------------------
    Inches ....... Inches ....... Inches ......... Inches ........  Inches     
   12 to 14 ......... 5 ............ 7 ............ 1/8 ...........  7/16      
-------------------------------------------------------------------------------
                      5 ............ 7 ............ 3/8 ...........  7/16      
                      6 ............ 8 ............ 3/8 ...........  7/16      
Larger than 14                                                                 
  to 20 ............. 8 ........... 10 ............ 3/8 ...........  7/16      
                     10 ......... 11 1/2 .......... 3/8 ...........  7/16      
                     12 ......... 13 1/2 .......... 3/8 ...........  7/15      
-------------------------------------------------------------------------------
                      8 ........... 10 ............ 3/4 ............  1/2      
Larger than 20                                                                 
  to 30 ............ 10 ......... 11 1/2 .......... 3/4 ............  1/2      
                     12 ......... 13 1/2 .......... 3/4 ............  1/2      
                     15 ......... 17 1/2 .......... 3/4 ............  1/2      
-------------------------------------------------------------------------------
                     12 ......... 13 1/2 .......... 3/4 ............  1/2      
                     16 ......... 17 1/2 .......... 3/4 ............  1/2      
Larger than 30                                                                 
  to 42 ............ 18 ......... 19 1/2 .......... 3/4 ............  1/2      
                     20 ......... 21 1/2 .......... 3/4 ............  1/2      
-------------------------------------------------------------------------------
                     16 ........... 20 ............. 1 .............  3/4      
Larger than 42                                                                 
  to 60 ............ 20 ........... 24 ............. 1 .............  3/4      
                     24 ........... 29 ........... 1 1/8 ...........  7/8      
-------------------------------------------------------------------------------
[FNNote:] These flanges may be clamped together by means of a central nut, or  
  by a series of bolts or some other equivalent mans of fastening. For hole    
  sizes smaller than shown in this table, use table A-1.                       
 
 
 
                                          TABLE A-6                            
                  GUIDE FOR CONSTRUCTION OF BAND TYPE GUARDS                   
                         Maximum Wheel Speed 7000 SFPM                         

-------------------------------------------------------------------------------
                                                                      Maximum  
                                            Thickness                 Distance 
        Minimum                             Thickness     Minimum     between  
        Material            Diameter of      of Band     Diameter    Centers of
     Specifications            Wheel            A        of Rivets     Rivets  
-------------------------------------------------------------------------------
                              Inches ....... Inches ..... Inches ....  Inches  
                              Under 8 ....... 1/16 ....... 3/16 .......  3/4   
Hot Rolled Steel SAE                                                           
  1008 ...................... 8 to 24 ........ 1/8 ........ 1/4 ........ 1     
                          Over 24 to 30 ...... 1/4 ........ 3/8 ...... 1 1/4   
-------------------------------------------------------------------------------
 
 


TABLES A-7 through A-18


    Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.  


 HISTORY 
   
1. New section filed 11-22-85; effective thirtieth day thereafter (Register
85, No. 48).


    Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.  


 HISTORY 
   
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, 
No. 48).


    Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.  


 HISTORY 
   
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, 
No. 48).


    Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.  


 HISTORY 
   
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, 
No. 48).


    Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.  


 HISTORY 
   
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, 
No. 48).


    Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.  


 HISTORY 
   
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, 
No. 48).


    Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.  


 HISTORY 
   
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, 
No. 48).

 HISTORY 
   
1. New Tables A-7 through A-18 filed 7-26-78; effective thirtieth day
thereafter (Register 78, No. 30).

2. Repealer of Tables A-7 through A-18 filed 11-22-85; effective thirtieth day
thereafter (Register 85, No. 48).

Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Appendix G

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