Subpart I
Grinding machines must have enough power to keep the spindle speed at safe levels during normal operation. See the power requirement in 1926.303(a) which requires sufficient power to maintain safe spindle speed under all conditions of normal operation.
All grinding machines must be equipped with safety guards that conform to ANSI B7.1-1970 and paragraph (d) of 1926.303. See the guarding requirement in 1926.303(b)(1) which explicitly requires safety guards in conformance with American National Standards Institute, B7.1-1970 and the additional requirements in 1926.303(d).
The safety guard must cover the spindle end, nut, and flange projections unless a specific exception applies. See the guard design requirement in 1926.303(b)(2) which states the guard shall cover the spindle end, nut, and flange projections.
The spindle end, nut, and outer flange may be exposed when the work itself gives suitable operator protection or on machines designed as portable saws. See the exceptions in 1926.303(b)(2)(i) and (ii) which allow exposures where the work provides protection or for machines designed as portable saws.
For floor-stand and bench-mounted external grinding, the wheel periphery and sides may be exposed up to 90°, except when work requires contact below the horizontal plane, in which case exposure may be up to 125°—and in either case the exposure must begin no more than 65° above the horizontal. See the exposure limits in 1926.303(c)(1).
Safety guards must be strong enough to withstand the effect of a bursting wheel. See the strength requirement in 1926.303(c)(1).
Work rests must be rigidly supported, readily adjustable, and kept no more than 1/8 inch from the wheel surface; offhand grinders must use such work rests. See the work rest requirements in 1926.303(c)(2) and the work-rest provision in 1926.303(e).
Cup-type wheels used for external grinding must have either a revolving cup guard or a band-type guard per ANSI B7.1-1970; other portable external grinding wheels must have protection hoods that meet paragraph (c)(5), except where specific exceptions apply. See the portable wheel guarding rules in 1926.303(c)(3).
Exceptions allow: (1) using a wheel with safety flanges when the work location makes guards impossible, and (2) using wheels 2 inches or less on a steel mandrel. See the exceptions in 1926.303(c)(3)(i) and (ii).
Portable wheels used for internal grinding must use safety flanges per paragraph (c)(6), except when the wheel is 2 inches or less on a steel mandrel or the wheel is entirely within the work being ground. See the internal grinding flange rules in 1926.303(c)(4) and exceptions in (c)(4)(i)–(ii).
When guards are required, they must be mounted to maintain proper alignment with the wheel and their fastenings and the guard must be strong enough to retain wheel fragments if the wheel breaks. See the mounting and fastening rules in 1926.303(c)(5) and the guard-mounting note in 1926.303(b)(2).
Safety flanges must be used only with wheels designed to fit them and must be of a type and assembly that will retain wheel pieces in case of breakage. See the safety flange requirement in 1926.303(c)(6).
Yes — all abrasive wheels must be closely inspected and ring-tested before mounting to ensure they have no cracks or defects. See the inspection and ring-test requirement in 1926.303(c)(7).
Grinding wheels must fit freely on the spindle and not be forced on; the spindle nut should be tightened only enough to hold the wheel in place. See the fit and nut-tightening rule in 1926.303(c)(8).
Employees using abrasive wheels must be protected by eye protection that meets the requirements of Subpart E of part 1926, unless adequate protection is provided by permanently attached eye shields on the bench or floor stand. See the eye protection rule in 1926.303(c)(9) and the Subpart E provisions for eye protection.
The basic rule states the maximum angular exposure shall not exceed 180°, but specific limits for floor-stand and bench grinders are tighter—90° normally and 125° when work requires contact below horizontal, starting no more than 65° above horizontal. See the general 180° limit and the specific bench/floor grinder limits in 1926.303(c)(1).
Yes — all abrasive wheels and tools must meet other applicable requirements of ANSI B7.1-1970, as noted in 1926.303(d). See the other requirements provision in 1926.303(d).
Guard fastenings must have strength that exceeds the strength of the guard to maintain proper alignment, except where the standard allows certain exposures; see 1926.303(b) and the guard-mounting requirement in 1926.303(b)(2).
Guards and their fastenings must be strong enough to retain fragments of the wheel in case of accidental breakage. See the fragment retention requirement in 1926.303(c)(5).
Yes — when the work location makes guards impossible, using wheels equipped with safety flanges as described in 1926.303(c)(6) is permitted as an alternative. See the option to use safety flanges in 1926.303(c)(3)(i) and the requirements for flanges in 1926.303(c)(6).
Employers must assess the workplace to determine hazards and select appropriate PPE, including eye protection for abrasive wheel operations, and document the assessment when PPE is required. See OSHA's PPE hazard assessment interpretation at https://www.osha.gov/laws-regs/standardinterpretations/2024-03-28 which explains the employer's duty to assess hazards, and see the abrasive wheel eye protection requirement in 1926.303(c)(9).
You must not force the wheel onto the spindle; replace the wheel or use the correct size so it fits freely and then tighten the spindle nut only enough to hold it in place. See the fit and nut guidance in 1926.303(c)(8).
A ring test is tapping the wheel to listen for a clear ring that indicates no cracks; it must be done before mounting to ensure the wheel has no cracks or defects. See the inspection and ring-test requirement in 1926.303(c)(7).