1910.219(b): Flywheel and Prime Mover Guards
Flywheels with any part 7 feet or less above the floor or platform must be guarded by a metal or woven wire enclosure, or guardrails 15 to 20 inches from the rim, with a toeboard if the flywheel goes into a pit or is within 12 inches of the floor. Flywheels through a working floor must be fully enclosed or railed, and guards above working areas must be strong enough to hold the flywheel if its shaft or mounting fails.
Key takeaways
- 1910.219(b) is part of OSHA's general industry standards (29 CFR Part 1910, Subpart O).
- OSHA cited it 55 times in the last 3 years, in 54 inspections, with $173,677 in current penalties.
- Most citations: IL (7), CT (6), PA (5).
- Related part: 1910.219(b)(1) Flywheels (51 citations).
- Free 5-minute toolbox talk for your crew below.
In this article
What this rule covers
29 CFR 1910.219(b) ("Prime-mover guards") is one requirement inside 1910.219 Mechanical power-transmission apparatus, an OSHA general industry standard (Part 1910, Subpart O). It includes 9 sub-paragraphs. The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.
Official text
(b) Prime-mover guards — 55 citations
(1) Flywheels. Flywheels located so that any part is seven (7) feet or less above floor or platform shall be guarded in accordance with the requirements of this subparagraph: Open (b)(1) 51 citations
(i) With an enclosure of sheet, perforated, or expanded metal, or woven wire; Open (b)(1)(i) 3 citations
(ii) With guard rails placed not less than fifteen (15) inches nor more than twenty (20) inches from rim. When flywheel extends into pit or is within 12 inches of floor, a standard toeboard shall also be provided;
(iii) When the upper rim of flywheel protrudes through a working floor, it shall be entirely enclosed or surrounded by a guardrail and toeboard.
(iv) For flywheels with smooth rims five (5) feet or less in diameter, where the preceding methods cannot be applied, the following may be used: A disk attached to the flywheel in such manner as to cover the spokes of the wheel on the exposed side and present a smooth surface and edge, at the same time providing means for periodic inspection. An open space, not exceeding four (4) inches in width, may be left between the outside edge of the disk and the rim of the wheel if desired, to facilitate turning the wheel over. Where a disk is used, the keys or other dangerous projections not covered by disk shall be cut off or covered. This subdivision does not apply to flywheels with solid web centers.
(v) Adjustable guard to be used for starting engine or for running adjustment may be provided at the flywheel of gas or oil engines. A slot opening for jack bar will be permitted.
(vi) Wherever flywheels are above working areas, guards shall be installed having sufficient strength to hold the weight of the flywheel in the event of a shaft or wheel mounting failure.
(2) Cranks and connecting rods. Cranks and connecting rods, when exposed to contact, shall be guarded in accordance with paragraphs (m) and (n) of this section, or by a guardrail as described in paragraph (o)(5) of this section. Open (b)(2) 3 citations
(3) Tail rods or extension piston rods. Tail rods or extension piston rods shall be guarded in accordance with paragraphs (m) and (o) of this section, or by a guardrail on sides and end, with a clearance of not less than fifteen (15) nor more than twenty (20) inches when rod is fully extended. 1 citations
Source: eCFR, text current as of 2026-10-15. Read all of 1910.219.
Where and how often it was cited
| Year | Citations |
|---|---|
| 2023 | 4 |
| 2024 | 19 |
| 2025 | 20 |
| 2026 | 12 |
Top states: IL (7), CT (6), PA (5), MN (5), OH (4)
Largest penalties
| Employer | Location | Penalty for this rule |
|---|---|---|
| THE GOODYEAR TIRE & RUBBER COMPANY | DANVILLE, VA | $13,415 |
| 156605 - PINE HALL BRICK CO., INC. (PLANT # 4) | MADISON, NC | $12,500 |
| ARTCO-BELL CORPORATION | TEMPLE, TX | $10,372 |
| WALKER MIDWEST LLC | ITASCA, IL | $10,000 |
| MAVIS TIRE SUPPLY LLC | SCHENECTADY, NY | $9,930 |
Free toolbox talk
A 5-minute crew talk on 1910.219(b), plus alerts when this rule changes. Free.
OSHA interpretation letters
- Guarding of flywheels on power presses. (1983-06-08)
- Subpart O -- Machinery and Machine Guarding, Mechanical Power-Transmission Apparatus. (1976-04-02)
- Clarification on the required strength of press flywheel guards (1975-12-18)
Related parts of this rule
- 1910.219(b)(1) Flywheels 51 citations
- 1910.219(b)(2) Cranks and connecting rods 3 citations
- 1910.219(b)(1)(i) 3 citations
Get your crew competent
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Frequently asked questions
When must a flywheel be guarded?
When any part is seven feet or less above the floor or platform.
How far must guardrails be from the rim?
Not less than 15 inches nor more than 20 inches from the rim.
What about flywheels above work areas?
Guards must be strong enough to hold the weight of the flywheel if the shaft or wheel mounting fails.
About this page
Sources
- 29 CFR 1910.219 (eCFR), text current as of 2026-10-15
- U.S. Department of Labor enforcement data: OSHA inspections, citations and accident records, copied nightly; data as of 2026-10-21
3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.