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Laws Related to Grinding Work

Industrial Safety and Health Act (excerpts)
(Act No. 57 of June 8, 1972)

Chapter I General Provisions

Article 1 (Purpose)
The purpose of this Act is to secure, in conjunction with the Labor Standards Act (Act No. 49 of 1947), the safety and health of workers in workplaces, as well as to facilitate the establishment of comfortable working environment, by promoting comprehensive and systematic countermeasures concerning the prevention of industrial accidents, such as taking measures for the establishment of standards for hazard prevention, clarifying the safety and health management responsibility and the promotion of voluntary activities with a view to preventing industrial accidents.

Article 3 (Responsibilities of Employer, etc.)
(1) The employer shall not only comply with the minimum standards for preventing industrial accidents provided for in this Act, but also endeavor to ensure the safety and health of workers in workplaces through creating a comfortable working environment and improving working conditions. He/She shall, furthermore, endeavor to cooperate in the measures for the prevention of industrial accidents to be taken by the State.
(2) – (3) omitted.

Article 4
Workers shall, not only observe matters necessary for preventing industrial accidents, but also endeavor to cooperate in the measures pertaining to prevention of industrial accidents conducted by employers or other said parties.

Chapter V Regulations concerning Machines, etc. and Harmful Substances

Article 42 (Restrictions on Transter, etc.)
Among machines, etc., other than specified machines, etc., which are listed in Appended Table 2, or require dangerous or harmful operations, or are used in a dangerous place, or used for preventing danger or health impairment, those defined by Cabinet Order shall not be transferred, leased or installed unless they conform to the construction code provided for by the Minister of Health, Labour and Welfare or are equipped with safety apparatus designated by the Minister of Health, Labour and Welfare.

Appended Table 2 (Related to Article 42)

  • (1) Rolling mill for kneading rubber, rubber compounds or synthetic resin, and their emergency stopping device.
  • (2) Class-2 pressure vessel (referring a pressure vessel other than a class-1 pressure vessel, which is prescribed by the Cabinet Order,same as in the next table)
  • (3) Small-sized boiler
  • (4) Small-sized pressure vessel (referring the class-1 pressure vessel prescribed by the Cabinet Order, same as next table)
  • (5) Safety device for press machine and shearing machine
  • (6) Explosion-proof electric apparatus
  • (7) Overload preventive device for crane and mobile crane
  • (8) Dust respirator
  • (9) Gas mask
  • (10) Woodworking circular saw and its kickback preventive device or teeth contact preventive device
  • (11) Powered press machine
  • (12) Automatic electric shock preventive device for AC arc welding equipment
  • (13) Personal insulating protective device
  • (14) Insulating device
  • (15) Safety helmet

Article 43
Machines, etc., driven by power which are not equipped with protective measures provided for by the Ordinance of the Ministry of Health, Labour and Welfare on projecting parts of moving parts, power transmission sections or speed regulatory sections shall neither be transferred nor be leased, and shall not be exhibited with a view to transfer or lease :

Chapter VI Measures in Placing Workers

Article 59 (Safety and Health Education)
(1) The employer shall, when a new worker is employed, give the said worker education for safety and/or health concerning work operations in which the worker is to be engaged, as provided for by the Ordinance of the Ministry of Health, Labor and Welfare.
(2) The provisions of the preceding paragraph shall apply mutatis mutandis when the contents of the operations have been changed.
(3) The employer shall, when a worker is to be placed in the dangerous or harmful operations provided for by the Ordinance of the Ministry of Health, Labor and Welfare, give the worker the special education for safety and/or health concerning the said operations, as provided for by the Ordinance of the Ministry of Health, Labor and Welfare.

Enforcement Order of the Industrial Safety and Health Act (excerpts)
(Cabinet Order No. 318, August 19, 1972)

Article 13 (Machines, etc. Subject to Be in Comformity with Standards or Equipped with Safety Devices Designated by the Minister of Health, Labour and Welfare)
(1) – (2) omitted.
(3) The machines, etc. defined by the Cabinet Order set forth in Article 42 of the Act (excluding the case in which the machines, etc., are clear not for domestic use) shall be the machines, etc. listed in followings:

  • (i) omitted.
  • (ii) Grinding machines, abrasive wheels and protective covers of the abrasive wheels;
  • (iii) – (xxxiv) omitted.

Ordinance on Industrial Safety and Health (excerpts)
(Ministry of Labour Ordinance No. 32 of September 30, 1972)

Part I General Rules

Chapter III Regulations Concerning Machines, etc., and Dangerous and Harmful Substances

Section 1 Regulations Concerning Machines, etc.


Article 25 (Protective Measures for Projecting Parts, etc., of Moving Parts)
(1) The protective measures prescribed by the Ordinance of the Ministry of Health, Labour and Welfare set forth in Article 43 of the Act shall be as follows:

  • (i) To make projecting part of moving parts a sunk-head type, or to provide a cover;
  • (ii) To provide a cover or an enclosure for a power transmission or speed control sections.

 

Article 27 (Use of Machines, etc., Comply with Construction Codes)
(1) The employer shall, as regards the machines, etc., listed in Appended Table 2 of the Act and machines, etc., listed in each item of paragraph (3) of Article 13 of the Order, not use the said machines, etc., unless they fulfill the construction code or safety devices provided by the Minister of Health, Labour and Welfare set forth in Article 42 of the Act.


Article 28 (Effective Maintenance of Safety Devices, etc.)
(1) The employer shall carry out the checkup and maintenance for a safety device, a cover, an enclosure, etc., provided pursuant to the Act and Ordinances based on the Act (hereinafter referred to as “safety device, etc.”) so that they may be used in effective conditions.


Article 29
(1) A worker shall, as regards the safety device, etc., observe the following matters:

  • (i) Not to remove the safety device, etc., nor to lose their function; (ii) When it is necessary to temporarily remove the safety device, etc., or to lose their function, to obtain in advance the permission by the employer ;
  • (ii) When it is necessary to temporarily remove the safety device, etc., or to lose their function, to obtain in advance the permission by the employer ;
  • (iii) When having removed the safety device, etc., or lost their functions by obtaining the permission of the preceding item, and after such necessity is over, to immediately restored to its original condition ;
  • (iv) When having found that safety device, etc., have been removed or been lost their functions, to immediately report the facts to the employer.

(2) The employer shall promptly take appropriate measures when the report pursuant to the provision of item (iv) of the preceding paragraph has been made.

Chapter IV Safety and Health Education

Article 36 (Work Necessitating Special Education)
(1) Dangerous or harmful work prescribed by the Ordinance of the Ministry of Health, Labour and Welfare set forth in paragraph (3) of Article 59 of the Act shall be as follows:

  • (i) Work involving replacement of grinding wheels or their test runs at the time of replacement;
  • (ii) – (xxxvii) omitted.

Article 38 (Preserving the Record of Special Education)
(1) The employer shall, when having given special education to workers, record the curricula and names of those who attended the said special education course and preserve the records for three years.

Chapter IX Inspection, etc.

Article 96 (Reports on Accidents)
(1) The employer shall, in the case of the following cases, submit a report by Form No.22 without delay to the Chief of the competent Labour Standards Inspection Office:

  • (i) When any of the following accidents have occurred in the workplace or in any attached buildings:
    • (a) omitted.
    • (b) Rupture of a centrifugal machine, or of a grinding wheel and other high speed rotating body.
    • (c) – (d) omitted.
  • (ii) – (x) omitted.

Part II Safety Standards

Chapter I Prevention of Dangers Due to a Machine

Section 1 General Standards

Article 101 (Prevention of Dangers Due to a Prime Mover, a Rotating Shaft, etc.)
(1) The employer shall provide an enclosure, a cover, a sleeve, an overbridge, etc., for a prime mover, a rotating shaft, a gear, a pulley, a belt, etc., of a machine, which are liable to cause dangers to workers.
(2) The employer shall, as regards set-screws and other fixtures attached to a rotating shaft, a gear, a pulley, a flywheel, etc., use those of sunk head type or provide a cover.
(3) The employer shall not use a protruded fastener for joining a belt.
(4) – (5) omitted.

Article 105 (Prevention of Dangers Due to Flying of Work Pieces, etc.)
(1) The employer shall, when it is liable to cause dangers to workers due to flying of cut or broken work pieces, etc., provide a cover or an enclosure for the machine dispersing the said work pieces, etc. However, this shall not apply to the case where providing a cover or an enclosure is difficult due to the nature of the work, and when having a worker use protective equipment.
(2) A worker shall, when having been instructed to use personal protective equipment in the case set forth in the proviso of the preceding paragraph, use it.

Article 106 (Prevention of Dangers Due to Flying of Chips, etc.)
(1) The employer shall, when it is liable to cause dangers to workers due to flying, etc., of chips from machines, provide a cover or an enclosure for the machine producing the said chips. However, this shall not apply to the case where providing a cover or an enclosure is difficult due to the nature of the work, and when having a worker use personal protective equipment.
(2) A worker shall, when having been instructed to use personal protective equipment in the case set forth in the proviso of the preceding paragraph, use it.

Article 110 (Wearing of a Work Cap, etc.)
(1) The employer shall, when it is liable to hair or clothes of the worker during the work caught in a power-driven machine, have the said worker wear appropriate work cap or work clothes.
(2) A worker shall, when having been instructed to wear a work cap or work clothes set forth in the preceding paragraph, wear them.

Article 111 (Prohibition of the Use of Gloves)
(1) The employer shall, when it is liable to fingers of the worker during the work caught in rotating blades of a drilling machine or a chamfering machine, not have the worker wear gloves.
(2) A worker shall, when having been prohibited to wear gloves in the case set forth in the preceding paragraph, not wear them.

 

Section 2 Machine Tool

Article 117 (Cover on Grinding Wheel)
(1) The employer shall, when rotating grinding wheel, which is liable to cause dangers to workers, provide a cover. However, this shall not apply to a grinding wheel with a diameter less than 50 mm.

Article 118 (Test Run of Grinding Wheel)
(1) The employer shall, as regards a grinding wheel, make a test run for one minute or longer before commencing the work for the day and for three minutes or longer when replacing a grinding wheel.

Article 119 (Prohibition of Operation of a Grinding Wheel at Speeds Exceeding Maximum Allowable Speeds)
(1) The employer shall, as regards a grinding wheel, not operate it at speeds exceeding the maximum allowable speeds.

Article 120 (Prohibition of Use of Side Surfaces of a Grinding Wheel)
(1) The employer shall not use the side surfaces of a grinding wheel except for a grinding wheel designed for use of their side surfaces.

Chapter IV Prevention of Explosions, Fires, etc.

Section 4 Control of Fires, etc.

Article 286 (Welding, etc., at Places Where Ventilation, etc., Is Insufficient)
(1) The employer shall, when carrying out the work welding, cutting, heating of metal or other using fire, or dry grinding using grinding wheels, chipping using a chisel or other work that is liable to produce sparks, at a place where ventilation is insufficient, not use oxygen for the purpose of ventilation.
(2) A worker shall not use oxygen for the purpose of ventilation in the case prescribed in the preceding paragraph.

Part III Health Standards

Chapter I Harmful Working Environment

Article 576 (Removal of Causes of Harmfulness)
(1) The employer shall, in a workshop where handling harmful substances, exuding gas, vapor or dust, workers are exposed to harmful light or ultrasonic waves, or sending noise or producing vibration, or is contaminated with pathogens, take necessary measures such as using of substitutes and improvement of working methods or machine, etc., to eliminate the causes of these harmful situations.

Article 577 (Control of Exuding of Gas, etc.)
(1) The employer shall take necessary measures such as making emission sources airtight and installation of a local exhaust ventilation system or general ventilation system at an indoor workshop where exuding gas, vapor, or dust in order to keep the concentration of gas, vapor or dust in the air in the said indoor workshop below harmful levels.

Chapter II Personal Protective Equipment, etc.

Article 593 (Respiratory Protective Equipment, etc.)
(1) The employer shall, in the work in extremely hot or cold places, work handling a large quantity of high-temperature or low-temperature or harmful substances, work exposed to harmful light, work in places exuding gas, vapor or dust, work threatened with extreme contamination with pathogens and other harmful work, provide suitable personal protective equipment such as protective clothes, eye protector and respiratory protective equipment in order to have workers engaging in the said work use them.

Article 595 (Personal Protective Equipment for Preventing Disorder from Noise)
(1) The employer shall, in the work carried out at the place sending extreme noise, provide earplugs or other personal protective equipment in order to have the worker engaging the said work use them.
(2) The employer shall, when having instructed workers engaging in work set forth in the preceding paragraph to use earplugs or other protective equipment, without delay, display the instruction to use the said protective equipment in a readily visible place so that workers engaging in work are readily aware of it.

Article 597 (Workers' Obligation to Use Personal Protective Equipment)
(1) The worker engaging in the work prescribed by Article 593 to 595 shall, when having been instructed to use personal protective equipment necessary for the said work by the employer, use the said personal protective equipment.

Rules on Special Education for Safety and Health (excerpts)
(Ministry of Labour Public Notification No. 92 of September 30, 1972)

Article 1 (Special Education Pertaining to the Work of Replacement, etc. of Grinding Wheels)
(1) Of the work listed in item (i) of Article 36 of the Ordinance on Industrial Safety and Health (hereinafter referred to as “Safety and Health Ordinance”), the special education in the paragraph (3) of Article 59 of the Industrial Safety and Health Act (Act No.57 of 1972, hereinafter referred to as the “Act”) (hereinafter referred to as “special education”) pertaining to the work of replacement of mechanical grinding wheels or their test runs at the time of replacement shall be conducted by the academic education and practical education.
(2) The academic education in the preceding paragraph shall be conducted as regard to each scope listed in the middle column of the following table for not less than the number of hours listed in the right column of the same table corresponding to the subject listed in the left column in the same table.

Subjects Scope Hours
Knowledge of mechanical grinding machines, mechanical grinding wheels and fixtures, etc. Types, structure and handling methods of mechanical grinding machines; types, composition, labeling, safety level and handling methods of mechanical grinding wheels; fixtures; covering; protective equipment; and grinding lubricant 4 hours
Knowledge of methods of fitting and test run of mechanical grinding wheels Confirmation of compatibility between mechanical grinding machines and mechanical grinding wheels; visual inspection and knocking sound test of mechanical grinding wheels; tightening methods and force; methods of balancing; and methods of test run 2 hours
Relevant legislation Relevant Articles of the Act, the Order for Enforcement of the Industrial Safety and Health Act (Cabinet Order No.318 of 1972; hereinafter referred to as the “Order”) and the Safety and Health Ordinance 1 hour

(3) The practical education in the paragraph (1) shall be conducted as regard to the methods of fitting and test run of mechanical grinding wheels for not less than 3 hours.

Article 2 (Special Education Pertaining to the Work of Replacement of Free Grinding Wheels)
(1) Of the work listed in item (i) of Article 36 of the Safety and Health Ordinance, the special education pertaining to the work replacement of free grinding wheels or their test run at the time of replacement shall be conducted by the academic education and practical education.
(2) The academic education in the preceding paragraph shall be conducted as regard to each scope listed in the middle column of the following table for not less than the number of hours listed in the right column of the same table corresponding to the subject listed in the left column in the same table.

Subjects Scope Time
Knowledge of free grinding machines, freehand grinding wheels, fixtures, etc Types, structure and handling methods of free grinding machines; types, composition, labeling, safety level and handling methods of free grinding wheels; fixtures; covering; and protective equipment 2 hours
Knowledge of methods of fitting and test operation of free grinding wheels Confirmation of compatibility between free grinding machines and free grinding wheels; visual inspection and knocking sound test of free grinding wheels; tightening methods and force; methods of; and methods of test run 1 hour
Relevant legislation Relevant Articles of the Act, the Order and the Safety and Health Ordinance 1 hour

(3) The practical education in the paragraph (1) shall be conducted as regard to the methods of fitting and test operation of freehand grinding wheels for not less than 2 hours.

Structural Standard for Grinders and Related Equipment (excerpts)
(Ordinance of the Ministry of Labour No. 8, July 1, 1971)

Chapter I Grinders

Article 1 (Grinding wheels)
(1) The grinding wheels which are mounted onto a grinder shall conform to the standards prescribed in Article 7 – Article 10.

Article 2 (Methods of Mounting Grinding Wheels, etc.)
(1) When mounting a grinding wheel onto a grinder, flanges shall be used which conform to the standards prescribed in Article 5 – Article 9. However this requirement shall not apply when the mounting flanges listed in the bottom section of the following table are used for the appropriate types of grinding wheels listed in the top section of the same table.
(2) The fixed-side flange shall be fastened to the grinding wheel shaft by means of a method utilizing keys or bolts, or by shrinkage fit, press fitting, or equivalent method.
(3) The screws which fasten the flange to the grinding wheel shaft shall tighten in the direction opposite the direction of rotation.
(4) When mounting a grinding wheel onto a grinder using a safety flange for a flat grinding wheel, rubber blotters shall be used.

Type of grinding wheel Mounting flange
Ring-shape or disc-shape grinding wheel Base plate
Cup-shape grinding wheel with nut, artillery shell-shape grinding wheel with nut or similar grinding wheel
Grinding wheel with nut
Flange with nut
Segmented grinding wheel Segmented flange
Grinding wheel with shaft Chuck
Flat grinding wheel installed onto a grinding shaft inside a precision internal grinder Bolts or other mounting flange

Article 3 (Shields)
(1) Grinders (excepting internal grinders) shall be equipped with a grinding wheel shield that conforms to the standards prescribed in Section 3.

Article 5 (Work Rests)
(1) Bench grinders and floor-stand grinders shall be equipped with work rests that allow the clearance with the periphery of the grinding wheel to be adjusted to within 3 mm or less.

Chapter II Grinding Wheels, etc.

Article 7 (Maximum Operating Speed)
(1) Grinding wheels shall include predetermined maximum operating speeds as prescribed in the following article and in Article 9.

Article 8 (Maximum Operating Speed of Flat Grinding Wheels, etc.)
(1) The maximum operating speed for flat grinding wheels, offset grinding wheels (including elastic grinding wheels; same below, excepting Article 13), and cutting grinding wheels shall be determined by conducting fracture speed tests using model grinding wheels created using the same binder that is necessary to create that grinding wheel.
(2) (Omitted)
(3) The fracture test prescribed in paragraph 1 shall be conducted for a minimum of 3 model grinding wheels, and the lowest value for the fracture rotation speed from the tests shall be used as the fracture rotation speed for that model grinding wheel.
(4) (Omitted)
(5) The value of the maximum operating speed for the grinding wheels listed in Paragraph 1 other than those listed in the preceding paragraph shall not exceed 1/2 of the facture rotation speed determined as prescribed in Paragraph 3. (For grinding wheels used at normal speeds, if the value exceeds the limit value for normal operating speed shown in Table 9-2, then the limit value listed in the table shall be used as the maximum.)

Table 9-2:Ordinary Grinding Wheel Peripheral Speed Limits (Units: m/s)

Grinding wheel type Limit of grinding wheel normal operating speed
Inorganic binder Organic binder
Flat With reinforce-ment Ordinary type 33 50
Super high-load type - 63
Thread grinding or groove grinding type 63 63
Crankshaft and camshaft grinding type 45 50
No reinforce-ment Diameter 100 mm or less, thickness 25 mm or less - 80
Diameter more than 100 mm but not more than 205 mm, thickness 13 mm or less - 72
Other dimensions - 50
Single taper type, double taper type, single recessed type, double recessed type, safety type, saucer type, or sawtooth saucer type 33 50
Dovetail shape Ordinary type 33 50
Thread grinding or groove grinding type 63 63
Type with relief Ordinary type 33 50
Crankshaft and camshaft grinding type 45 50
Ring type or ring-shape segments 30 35
Straight cup or taper cup 30 40
Disc type or disc-shape segments 33 45
Offset type (diameter 230 mm or less, thickness 10 mm or less) No reinforcement - 57
With reinforcement - 72
Cutting No reinforcement - 63
With reinforcement - 80

Article 10 (Speed Test)
(1) For grinding wheels with a diameter of 100 mm or more, a speed test must performed for each lot at a speed that is 1.5 times the maximum operating speed of that grinding wheel.
(2) For the grinding wheel products prescribed in the preceding paragraph (excepting products where abnormalities were found; same below in this and the following paragraph), when the speed test prescribed in the preceding paragraph is performed for 10% of the product quantity (5 when total quantity is less than 5), the products in the lot shall be considered to have passed the test if no abnormalities are found in any of the tested products.
(3) If the speed test prescribed in Paragraph 1 was performed for all grinding wheel products prescribed in Paragraph 1, if the abnormality rate was 5% or less then those grinding wheel products which did not display abnormalities shall be considered to have passed the test.

Article 14 (Dimensions, etc. of Grinding Wheels)
(1) Grinding wheel dimensions shall be the values listed in the bottom section of Table 9-3, according to the grinding wheel types listed in the middle section of the table and the grinding wheel maximum operating speed category listed in the top section of the table.
(2) Grinding wheels shall be the types listed in the middle section of Table 9-3, according to the grinding wheel maximum operating speed category listed in the top section of the table

Table 9-3:
Dimension Limit for each Peripheral Speed in Structural Standard for Grinders and Related Equipment (Units: mm)

Grinding wheel maximum operating speed category
(units: m/s)
Grinding wheel type Dimensions (units: mm)
Outer diameter
(D)
Thickness
(T)
Hole diameter
(H)
Recessed part diameter
(P)
Thickness of mounting part
(E)
Diameter of flat portion of mounting part
(J or K)
Edge thickness
(W)
Ordinary speed All types 1,500 or less for cutting wheels   0.7D or less 1.02Df + 4 or more T/4 or more for straight cup or and taper cup grinding wheels.
T/2 or more for single recessed, double recessed, saucer, and sawtooth saucer grinding wheels.
Df + 2R or more E or less
Speed other than ordinary speed 45 m/s or less Flat, single taper, double taper, single recessed, double recessed, safety, dovetail, and grinding wheels with relief 1,065 or less D/75 or more, 610 or less 0.6D or less 1.02Df + 4 or more 2/3T or more Df + 2R or more  
More than 45 m/s up to 60 m/s Flat, single taper, double taper, single recessed, double recessed, safety, dovetail, and grinding wheels with relief, and offset grinding wheels 1,065 or less D/50 or more, 305 or less 0.5D or less 1.02Df + 4 or more 2/3T or more Df + 2R or more  
More than 60 m/s up to 80 m/s Flat, dovetail, offset, and cutting grinding wheels 1,500 or less for cutting grinding wheels. 760 or less for other types. D/50 or more, 152 or less 0.33D or less     Df + 2R or more  
More than 80 m/s up to 100 m/s Flat, dovetail, offset, and cutting grinding wheels 1,500 or less for cutting grinding wheels. 760 or less for other types. D/50 or more, 80 or less 0.2D or less     Df + 2R or more  

Article 15 (Requirements for Flanges)
(1) Flanges shall utilize materials with tensile strength equivalent to cast iron products conforming to the 2 standards prescribed in Japan Industrial Standard G5501:1956 (Gray Iron Castings), and shall not deform.
(2) The diameters and contact widths of flanges (excepting the flanges prescribed in Article 19, Paragraph 1) shall be equal on the fixed side and moving side.

Chapter III Grinding Wheel Shields

Article 28 (Adjusting the Clearance with the Grinding Wheel)
(1) Shields used with bench grinders and floor-stand grinders shall permit adjustment of the clearance between the grinding wheel and surrounding shield at the location where grinding is required to within 10 mm or less through the use of adjustment pieces or other means.

Chapter IV Miscellaneous Rules

Article 29 (Labeling)
(1) Grinders shall be labeled with the items enumerated below in a location which is easily visible.

  • (i) Manufacturer name
  • (ii) Month and year of manufacture
  • (iii) Rated voltage
  • (iv) no-load operating speed
  • (v) Diameters, thicknesses, and hole diameters of grinding wheels which can be used
  • (vi) Direction of grinding wheel rotation

(2) Grinding wheels must be labeled with the manufacturer’s name, binder type, and maximum operating speed.
(3) Regardless of the provisions of the preceding paragraph, grinding wheels with diameters of less than 75 mm shall be bear labeling on each package.
(4) The shield shall be labeled with the grinding wheel maximum operating speed, thickness, and diameter.

Article 30 (Exceptions)
(1) This labeling requirement does not apply to the grinding wheels and shields listed below.

  • (i) Grinding wheels with diameters less than 50 mm
  • (ii) Shields used with the grinding wheels in the (1) above