OSHA 30 study materials
OSHA 30 study resources

250-Ton Press: A Removed Gate, Finger-Clearing the Die, and 'Inch' Mode Die Changes

OSHA 30 · Put your knowledge to work in context.

All case studies

250-Ton Press: A Removed Gate, Finger-Clearing the Die, and 'Inch' Mode Die Changes

A 250-ton mechanical power press runs a progressive die on a two-hand control. Three weeks ago the operators removed the barrier gate because it 'hit the stock feeder.' They now reach into the die area with their fingers to knock out slugs after each stroke - 10 to 15 times per shift, about 30 seconds each time. The press is energized with the flywheel turning all shift. The disconnect is in a locked electrical room, and only the plant manager has a key. Die changes happen weekly and take about two hours; the die setter uses inch mode to jog the ram while reaching in to align the die. No one has inspected the press safeguards in over a year.

1. The plant manager says the two-hand control is a guard, so the press is protected. Evaluate that claim under 1910.212 and 1910.217.

Read the worked answer

A two-hand control is a device, not a guard, and it protects only one window of time. 1910.212(a)(1) requires one or more methods of machine guarding to protect the operator and others from point-of-operation hazards. 1910.217(c)(1) is the press-specific requirement: the point of operation of a mechanical power press must be protected by a guard or device that prevents the operator's hands from entering the point of operation during the downward stroke.

Why the claim fails here:

  1. The two-hand control protects only while both palms are on the buttons. The slugs are knocked out after the stroke, when the operator's hands are inside the die and the buttons are free - and a mechanical press with a failing clutch or a repeat can cycle again.
  2. The control must be located so the slide cannot complete a full stroke before the operator can remove a hand from the control and reach the point of operation. Nobody has verified that distance; it depends on press speed, stopping performance and the die, not on the control being present.
  3. The barrier gate was physically removed. Whatever protection the gate provided is gone, and no alternative measure replaced it.
  4. 1910.217 also requires periodic and regular inspection of guards and devices. Over a year with no inspection, and a guard removed and not restored, is an inspection program failure as well as a guarding failure.

Judgment point: the hazard is not 'hands on buttons.' The hazard is 'fingers in a die on an energized press.' A safeguard is adequate only if it is evaluated against the actual task the operator performs, not against the clearest part of the cycle.

2. Can the slug clearing qualify for the minor servicing exception to lockout/tagout? What would the employer have to prove?

Read the worked answer

The exception exists but has three independent requirements, and this employer meets none of the last two. 1910.147(a)(2)(ii)(B) removes from lockout coverage servicing during normal production operations when the activity is minor, routine, repetitive, and integral to the use of the equipment for production, and is performed using alternative measures that provide effective protection.

Applying it:

  • Minor, routine, repetitive, integral - clearing slugs 10-15 times a shift, 30 seconds at a time, in the middle of a production run, plausibly fits this prong.
  • Alternative measures providing effective protection - this is where the employer fails. There is no gate, no interlock, no presence-sensing device, no push stick, no fixture. Bare fingers in a die is the absence of an alternative measure, not an alternative measure.
  • Not a substitute for guarding - even a valid minor-servicing determination under 1910.147 does not excuse the machine guarding requirements in 1910.212 and 1910.217. Two separate standards, two separate obligations.

The key organizational point: the fact that the disconnect is in a locked room and only the plant manager holds the key is not a legal excuse - it is a designed barrier to de-energization. An employer cannot make lockout infeasible through its own key control and then claim the exception.

Acceptable alternatives, roughly in order of preference: an interlocked gate that stops or prevents slide motion when opened and requires a reset; a die enclosure with openings too small to admit a finger; a vacuum or air-blast slug removal system; tooling (hook, push stick) long enough to keep hands out of the die. Judgment point: the 30-second task is the entire risk - the shorter and more frequent the reach-in, the more likely a worker treats it as trivial and the more certain the eventual amputation.

3. During weekly die changes the setter jogs the ram in inch mode with his hands in the die. Evaluate this practice and describe the controls that must be in place.

Read the worked answer

Die changing is not minor servicing. It is a multi-hour, non-routine task involving the die, the ram, gravity, stored energy in springs and flywheel, and a person whose hands are inside the point of operation. The 1910.147(a)(2)(ii)(B) exception does not reach it. It requires full lockout under 1910.147.

What the practice lacks:

  • No energy isolation. 'Inch mode' is a control mode of an energized machine; it is not isolation. A control failure, a stuck valve, a repeat, or another employee at the control panel can drop the ram on the setter's hands.
  • No written procedure. 1910.147(c)(4) requires a documented energy control procedure specific to the press, covering shutdown, isolation, application of locks and tags, release of stored energy (blocking the ram against gravity, releasing spring energy, allowing the flywheel to stop), and verification.
  • No verification step. 1910.147 requires the authorized employee to verify isolation by attempting to start the equipment or measuring for zero energy. Nobody does that here.
  • Access barrier. Only the plant manager holds the disconnect key. That means the authorized employee cannot apply his own lock, so the core principle - one lock, one person, one key - cannot be met.
  • No periodic inspection. 1910.147 requires a periodic inspection of the energy control procedure at least annually; none has occurred.

Required controls: trained and authorized die setters; individual locks and keys issued to each authorized employee; a die-specific written procedure including ram blocking; a verification step before hands enter; and a periodic inspection with documentation.

Judgment point: inch mode is often treated by experienced setters as a normal way to work, precisely because they have done it for years without injury. That experience is survivorship bias, not evidence of safety. The setter's skill reduces the frequency of the error; it does not reduce the consequence.