kopik
Create
Industry & mechanicsVerified by Kopik: Official sources reviewed and answers tested by Kopik

Machine guarding & amputation prevention for machine tools under OSHA 29 CFR 1910, Subpart O

Covers OSHA's machine-guarding standards for metal-cutting machine tools: point-of-operation guarding under 29 CFR 1910.212, mechanical power press safeguarding, inspection and training requirements under 1910.217 (two-hand controls, presence-sensing devices, Table O-10 guard openings, the safety-distance formula), abrasive wheel and work-rest rules under 1910.215, power-transmission guarding under 1910.219, the 2025 National Emphasis Program on Amputations (CPL 03-00-027), and official OSHA interpretation letters on lathes, drill presses, die-setting, and awareness barriers. Built for HSE and maintenance managers, shop supervisors, and machine-tool integrators who need article-level, citable answers rather than general safety advice. Curated by Kopik from public sources: Office of the Federal Register / eCFR and the U.S. Occupational Safety and Health Administration (U.S. federal government works, public domain).

Ask your question

Free account required

Each question stands alone · 1 free a month, then with a subscription.

Answers are written by a language model solely from this base's documents, with numbered sources. They can be wrong and aren't legal, medical or financial advice: check the sources before any important decision.

This assistant answers questions about OSHA machine guarding and amputation prevention in U.S. general industry, with a focus on metal-cutting machine tools, power presses, grinders and power-transmission parts. It is meant for HSE and maintenance managers, shop supervisors and machine-tool integrators who need answers tied to a specific paragraph. Its sources are the eCFR text of 29 CFR 1910 Subpart O, OSHA directives, interpretation letters, the Machine Guarding eTool and OSHA publication 3170.

The general duty to guard every machine (29 CFR 1910.212)

Section 1910.212(a)(1) requires one or more methods of machine guarding to protect the operator and other employees in the machine area from hazards such as the point of operation, ingoing nip points, rotating parts, flying chips and sparks. Barrier guards, two-hand tripping devices and electronic safety devices are given as examples.

Guards must be affixed to the machine where possible, or secured elsewhere if attachment is not possible, and the guard must not create an accident hazard itself. Where no specific standard applies, a point-of-operation guard must be designed to keep any part of the operator's body out of the danger zone during the operating cycle.

Special hand tools for placing and removing material may supplement protection, but they cannot replace the guarding the section requires. Machines designed for a fixed location must also be securely anchored to prevent walking or moving.

Revolving drums, barrels and containers must be guarded by an enclosure interlocked with the drive mechanism, so they cannot revolve unless the guard enclosure is in place.

Abrasive wheels and grinders (29 CFR 1910.215)

Abrasive wheels may only be used on machines fitted with safety guards that cover the spindle end, nut and flange projections. The standard sets maximum angular exposures by machine type, for example 90 degrees (one-fourth of the periphery) on bench and floor stands and 180 degrees on cylindrical grinders.

On offhand grinding machines, work rests must be rigid, adjustable for wheel wear and kept adjusted closely to the wheel with a maximum opening of one-eighth inch, so the work cannot jam between the wheel and the rest.

Before mounting, every wheel must be closely inspected and sounded by the user (the ring test), and the spindle speed must be checked so it does not exceed the maximum operating speed marked on the wheel.

Guard material depends on wheel speed: cast iron or malleable iron guards are used up to 8,000 surface feet per minute, and cast steel or structural steel guards above 8,000 and up to 16,000 surface feet per minute. Type 27 and Type 28 wheels may only be used with a safety guard located between the wheel and the operator.

Belts, shafts, couplings and other power-transmission parts (29 CFR 1910.219)

Section 1910.219 covers the parts that carry power to the machine. Clutches, cutoff couplings and clutch pulleys with projecting parts located seven feet or less above the floor or working platform must be enclosed by a stationary guard.

Projecting keys, setscrews and other projections in revolving parts must be removed, made flush or guarded by a metal cover. Projecting shaft ends must present a smooth edge and end and may not project more than one-half the shaft diameter unless guarded by nonrotating caps or safety sleeves.

Friction drives are also covered: the driving point must be guarded where exposed to contact, arm or spoke friction drives and web friction drives with holes in the web must be entirely enclosed, and projecting belts on friction drives must be guarded where exposed. OSHA also recommends that no projecting setscrews or oilcups be used in any revolving pulley or machine part.

Which motions and actions cause amputations

OSHA's Machine Guarding eTool groups hazards into motions (rotating, reciprocating, transverse) and actions (cutting, punching, shearing, bending). Reciprocating motion can strike a worker or catch them between a moving and a stationary part, while transverse motion can catch a worker in a pinch or shear point.

Bending action, found on power presses, press brakes and tubing benders, is hazardous at the point of operation where stock is inserted, held and withdrawn. The assistant can help you map these hazards on a given machine to the paragraph that applies.

Frequently asked questions

Does OSHA's point-of-operation guarding requirement apply to drill presses and lathes?

Yes. In a letter dated October 15, 1990, OSHA stated that 1910.212(a)(1) applies to drill presses and lathes and that its policy is to require protection by guarding methods such as barrier guards.

Does OSHA approve or certify specific guards or safety devices?

No. The same 1990 letter states that OSHA does not endorse or approve safety devices. It mentions testing by a Nationally Recognized Testing Laboratory (NRTL) or by the manufacturer's own equipped laboratory as ways to obtain approval data.

Which machines usually need point-of-operation guarding?

Section 1910.212(a)(3)(iv) lists guillotine cutters, shears, alligator shears, power presses, milling machines, power saws, jointers, portable power tools, and forming rolls and calenders. The list gives examples and is not limited to these machines.

Do fan blades need a guard?

When the periphery of fan blades is less than seven feet above the floor or working level, the blades must be guarded. The guard openings may be no larger than one-half inch.

Why might an organic bonded wheel not ring during the ring test?

The standard notes that organic bonded wheels do not emit the same clear metallic ring as vitrified and silicate wheels. Wheels must also be dry and free from sawdust when tested, otherwise the sound is deadened.

For developers and agents

Embed / API / MCP

Connect this base to Claude, Cursor, ChatGPT or your own app. Each API or MCP request costs €0.10, charged to your Kopik credit (not charged if nothing is found). You need an API key: create one from your dashboard.

MCP for your agents

This base's MCP server URL (tools ask_base and search_base):

MCP URL
https://kopik.io/api/mcp?base=us-osha-machine-guarding-amputation
Claude Code, Cursor and other clients
Claude Code
claude mcp add --transport http kopik-us-osha-machine-guarding-amputation "https://kopik.io/api/mcp?base=us-osha-machine-guarding-amputation" --header "Authorization: Bearer kpk_…"
JSON config (mcpServers)
{
  "mcpServers": {
    "kopik-us-osha-machine-guarding-amputation": {
      "url": "https://kopik.io/api/mcp?base=us-osha-machine-guarding-amputation",
      "headers": {
        "Authorization": "Bearer kpk_…"
      }
    }
  }
}

REST API for your apps

mode is "answer" (written answer + sources) or "passages" (raw passages only). Add an optional maxPriceCents to cap the price: if the base costs more, the call is refused and nothing is charged.

curl
curl -X POST https://kopik.io/api/v1/bases/us-osha-machine-guarding-amputation/query \
  -H "Authorization: Bearer kpk_…" \
  -H "Content-Type: application/json" \
  -d '{"question": "Your question here", "mode": "answer"}'

Getting started

  1. Create a key in your dashboard and top up your credit.
  2. Replace kpk_… with your key.
  3. Full details (responses, errors, JS and Python examples): developer docs.