Mechanical power presses requirements

The person reconstructing or modifying a mechanical power press is responsible for doing the work in accordance with the requirements in paragraph (b) of the standard. See 1910.217(a)(4) and the general construction/guarding requirements in 1910.217(b).

• This means anyone who rebuilds, alters, or modifies a press must design and fit components so the press meets the guarding, control, brake, counterbalance, electrical, and other requirements spelled out in paragraph (b).
• Employers and contractors should review each applicable 1910.217(b) subsection to confirm compliance before returning a press to service.

Press brakes, hydraulic and pneumatic power presses, bulldozers, hot bending and hot metal presses, forging presses and hammers, riveting machines, and similar fastener applicators are excluded from this section. See 1910.217(a)(5).

• If your machine is one of the listed types, other OSHA standards may still apply—check the specific standard for that machine type.
• If the machine is not listed, follow the press requirements in 1910.217.

Machine components must be designed, secured, or covered to minimize hazards from breakage, loosening, falling, or release of mechanical energy. See 1910.217(b)(1).

• Examples include enclosing springs or using retainers so parts cannot be ejected, shielding rotating parts, and using retaining devices on fasteners.
• Regular inspection and maintenance are necessary to ensure those protective measures remain effective.

Friction brakes used to stop or hold a slide must be self-engaging (they stay engaged unless power is applied to disengage them) and must have enough capacity to stop slide motion quickly and hold it at any point in travel. See 1910.217(b)(2).

• In practice, that means brakes should be fail-safe (engage without power) and sized for the slide plus tooling mass.
• Employers should verify braking performance during maintenance and after modification.

Machines with full-revolution clutches must include a single-stroke mechanism, and if that mechanism depends on springs, the springs must be compression-type guided so coils cannot interleave if a spring breaks. See 1910.217(b)(3)(i) and 1910.217(b)(3)(ii).

• Use compression springs on rods or inside tubes or other guided arrangements to prevent coil interleaving and loss of spring function.
• If your press has a full-revolution clutch, confirm a functioning single-stroke mechanism is provided and maintained.

Foot pedal mechanisms must be protected to prevent unintended operation from falling/moving objects or accidental stepping; they must have a nonslip pad, use compression-type return springs guided to prevent coil interleaving, and any counterweight path must be enclosed. See 1910.217(b)(4)(i), 1910.217(b)(4)(ii), 1910.217(b)(4)(iii), and 1910.217(b)(4)(iv).

• Ensure pedal surfaces are nonslip and firmly attached.
• Enclose counterweight paths and use guided compression-return springs to reduce failure risks.

Hand-lever-operated presses must have a spring latch on the operating lever to prevent premature or accidental tripping, and hand-tripped presses with more than one operating station must have interlocked levers that only allow tripping by the concurrent use of all levers. See 1910.217(b)(5)(i) and 1910.217(b)(5)(ii).

• Check that latches and interlocks are present and functioning during inspections.
• Train operators to use concurrent levers correctly where required.

A two-hand trip must protect each operator's hand control against unintentional operation, require both hands concurrently to trip the press, and on multiple-operator presses each operator must have a separate set of controls. See 1910.217(b)(6)(i) and 1910.217(b)(6)(iii).

• Two-hand systems must be arranged by design, construction, and/or separation to prevent one-handed operation.
• Two-hand controls on full-revolution clutch machines must also incorporate an antirepeat feature per 1910.217(b)(6)(ii).

For machines using part-revolution clutches the clutch must release and the brake apply when the external clutch engaging means is removed, deactivated, or deenergized; a red stop control must immediately deactivate the clutch and apply the brake and override other controls; and a selector must be provided to choose Off, "Inch," Single Stroke, and Continuous (when furnished). See 1910.217(b)(7)(i), 1910.217(b)(7)(ii), and 1910.217(b)(7)(iii).

• The red stop must be momentary and able to stop operation regardless of other settings.
• Ensure stroking selectors are present and labeled so operators understand available modes.

The "Inch" operating means must either require concurrent use of both hands to actuate the clutch or be a single protected control located so the worker cannot reach into the point of operation while using it. See 1910.217(b)(7)(iv)(a) and 1910.217(b)(7)(iv)(b).

• If using a single control for "Inch," place it so workers cannot reach the die area while activating it and protect it against accidental actuation.

Two-hand controls for single-stroke must be protected against unintended operation, require concurrent pressure from both hands (with adjustment possible to ensure this during die closing), include an antirepeat feature, and be designed so release of all hand controls is required before resuming an interrupted stroke for systems manufactured/installed on or after August 31, 1971. See 1910.217(b)(7)(v)(a), 1910.217(b)(7)(v)(b), 1910.217(b)(7)(v)(c), and 1910.217(b)(7)(v)(d).

• The antirepeat prevents automatic reactivation without releasing the controls.
• Adjust and test control sensitivity so both hands must actively apply pressure during the critical portion of the stroke.

Controls for more than one operating station must be designed and supervised so they are activated/deactivated in complete sets (two hand controls per station), and the clutch/brake system must prevent actuation if all operating stations are bypassed; systems offering single and continuous functions must allow employer supervision of continuous circuits and require a prior operator action beyond selecting Continuous to start continuous stroking. See 1910.217(b)(7)(vii) and 1910.217(b)(7)(viii).

• Employers should be able to supervise and verify that multi-station controls are complete and not bypassed.
• For continuous mode, ensure additional safeguards (e.g., supervisory enable) are required before continuous stroking can begin.

If foot control is provided, the selection between hand and foot control must be separate from the stroking selector and capable of employer supervision; foot tripping controls must be protected so falling/moving objects or accidental stepping cannot operate them. See 1910.217(b)(7)(ix) and 1910.217(b)(7)(x).

• Use guarded or recessed foot controls and a clear, supervised selector to prevent unintended actuation.

Air-clutch control design must prevent a significant increase in normal stopping time due to a failure within the operating valve mechanism, and must inhibit further operation if such a failure occurs; this applies to air-valve clutch/brake controls manufactured/installed on or after August 31, 1971. See 1910.217(b)(7)(xi).

• Maintain and test air-valve mechanisms so failures that slow stopping are detected and the press is inhibited from restarting.

The clutch/brake control must automatically prevent Single Stroke or Continuous functions unless the motor is energized and turning forward, must automatically deactivate on failure of power or pressure supply to the clutch engaging means, and must automatically deactivate on failure of counterbalance air supply; reactivation requires restoration of normal supply and use of the tripping mechanism(s). See 1910.217(b)(7)(xii), 1910.217(b)(7)(xiii), and 1910.217(b)(7)(xiv).

• Design controls so loss of motor direction, clutch power, or counterbalance air automatically stops or blocks hazardous functions until corrected.

Press control systems must have a main power disconnect switch that can be locked only in the Off position, protect the motor start button from accidental operation, use starters that disconnect the drive motor on control voltage or power failure and require the start button to restart, limit a.c. control circuits to nominal 120 V from an isolated transformer (and d.c. to nominal 240 V isolated), and protect clutch/brake circuits against accidental ground faults. See 1910.217(b)(8)(i), 1910.217(b)(8)(ii), 1910.217(b)(8)(iii), 1910.217(b)(8)(iv), and 1910.217(b)(8)(v).

• Ensure lockable disconnects are accessible and labeled; verify control circuits use isolated supplies and protective wiring practices.

Electrical clutch/brake control circuits must include features (for example, relays, limit switches, and static output circuits) to minimize the possibility of an unintended stroke if a control component fails. See 1910.217(b)(8)(vi).

• Designers should include redundancy and fail-safe logic so single-component failures do not cause an accidental press stroke.
• Periodic functional testing of relays and limit switches is recommended to detect failures.

Slide counterbalance systems must retain parts in case of breakage for springs, hold the slide and attachments at midstroke without the brake for spring systems, have piston/rod retention in air cylinders, hold the slide at any point without brake for air cylinders, and include protection against sudden loss of air pressure. See 1910.217(b)(9)(i), 1910.217(b)(9)(ii), 1910.217(b)(9)(iii), 1910.217(b)(9)(iv), and 1910.217(b)(9)(v).

• Use retaining hardware and fail-safe valves so the slide cannot free-fall or move unexpectedly if a counterbalance component fails.
• Inspect counterbalance components regularly and follow manufacturers' service limits.

Air controlling equipment must be protected against foreign material and water entering the pneumatic system, and a means of air lubrication must be provided when needed. See 1910.217(b)(10).

• Install filters, dryers, and automatic drains as appropriate and provide oilers if manufacturer recommends lubrication for pneumatic devices.

Hydraulic system pressures must not exceed the safe working pressure rating of any component, and all pressure vessels used with presses must conform to the ASME Code for Pressure Vessels, 1968 Edition, as incorporated by reference in [1910.6]. See 1910.217(b)(11), 1910.217(b)(12), and 1910.6.

• Use components rated for maximum system pressures and have pressure relief devices set within safe limits.
• Ensure any pressure vessels have required ASME stamps and inspections per the referenced code.

When required by paragraph (c)(5), the control system must be built so a failure within the system does not prevent normal stopping action but does prevent initiation of a successive stroke until the failure is corrected; the failure must be detectable by a simple test or indicated by the control system. See 1910.217(b)(13) and the cross-reference to 1910.217(c)(5).

• Implement self-monitoring or simple test procedures so failures in safety-related control components are evident and prevent restart until fixed.

The brake monitor must be constructed to automatically prevent activation of a successive stroke if the stopping time or braking distance deteriorates to the point where the safety distance used does not meet the requirements of 1910.217(c)(3)(iii)(e) or 1910.217(c)(3)(vii)(c). See 1910.217(b)(14)(i).

• Brake monitors should be tested regularly and set to hold the press from restarting when braking performance degrades below safe limits.

Every power press control system must have a main power disconnect switch that can be locked only in the Off position. See 1910.217(b)(8)(i).

• Provide lockout/tagout capability at that disconnect and ensure authorized personnel can secure it during maintenance per your LOTO procedures.

The initiation of continuous run must require a prior action or decision by the operator in addition to selecting Continuous on the stroking selector, so that actuation of the operating means will not result in continuous stroking without that prior action. See 1910.217(b)(7)(viii).

• Employers should implement and train operators on the required enabling action (for example, a separate start pushbutton or supervisory control) so continuous mode cannot be entered accidentally.

Yes; spring counterbalances must be capable of holding the slide and its attachments at midstroke without the brake applied, and air counterbalance systems must have means to hold the slide at any point without the brake and include protection to prevent sudden loss of capability on air supply failure. See 1910.217(b)(9)(ii), 1910.217(b)(9)(iv), and 1910.217(b)(9)(v).

• For air counterbalances, include check valves, accumulators, or mechanical locks so a loss of air does not allow uncontrolled slide movement.

Employers can review the complete mechanical power press standard at 1910.217. See that section for all detailed guarding, control, electrical, and counterbalance requirements.

• Use the section links (for example, 1910.217(b)(4) for pedals or 1910.217(b)(8) for electrical) to find specific obligations quickly.

The employer is responsible for providing and ensuring use of point of operation guards on every operation performed on a mechanical power press. See 1910.217(c)(1)(i).

• This duty includes selecting, installing, and maintaining guards or properly applied point-of-operation devices for each press operation.
• If the point of operation opening is one‑quarter inch or less, the requirement does not apply as provided in 1910.217(c)(1)(ii).

The requirement to provide point of operation guards does not apply when the point of operation opening is one‑quarter inch or less. See 1910.217(c)(1)(ii).

• Even when this exception applies, employers should still evaluate hazards and use other protective measures if necessary.
• Table O-10 is referenced in the standard for permissible openings and related guidance: see 1910.217(c)(1)(i).

A point of operation guard must prevent entry of hands or fingers, meet Table O‑10 opening limits, create no pinch point with moving parts, use fasteners not readily removable by the operator, facilitate inspection, and offer maximum visibility consistent with other requirements. See 1910.217(c)(2)(i).

• Prevent entry by reaching through, over, under, or around the guard (1910.217(c)(2)(i)(a)).
• Conform to maximum permissible openings in Table O‑10 (1910.217(c)(2)(i)(b)).
• Not create pinch points between the guard and moving machine parts (1910.217(c)(2)(i)(c)).
• Use fasteners not readily removable by the operator (1910.217(c)(2)(i)(d)).
• Be easy to inspect (1910.217(c)(2)(i)(e)).
• Provide maximum visibility consistent with other requirements (1910.217(c)(2)(i)(f)).

A die enclosure guard must be attached to the die shoe or stripper in a fixed position. See 1910.217(c)(2)(ii).

• Fixed attachment to the die shoe or stripper ensures the guard moves with the die and maintains the required protection at the point of operation.
• If the enclosure does not meet the full requirements, it must be used only with suitable point of operation devices as described in 1910.217(c)(2)(vii).

A fixed barrier guard must be attached securely to the press frame or bolster plate, and an interlocked press barrier guard must be attached to the press frame or bolster and interlocked with the press clutch control so the clutch cannot be activated unless the guard (or its movable sections) is in position and conforms to Table O‑10. See 1910.217(c)(2)(iii) and 1910.217(c)(2)(iv).

• Interlocks must prevent press activation when the guard is open or not properly positioned.
• Guards must meet the dimensional limits in Table O‑10 to ensure adequate separation.

No—hinged or movable sections of an interlocked press barrier guard must not be used for manual feeding. See 1910.217(c)(2)(v).

• The guard must prevent opening of the interlocked section and reaching into the point of operation prior to die closure or before slide motion stops; see 1910.217(c)(3)(ii).
• If manual feeding is necessary, use an approved point of operation device, such as a pull‑out, restraint, two‑hand control, or other device listed in 1910.217(c)(3).

Only authorized personnel may adjust an adjustable barrier guard, and those personnel must have knowledge of Table O‑10 and the subparagraph's provisions. See 1910.217(c)(2)(vi).

• The guard must be securely attached to the press bed, bolster plate, or die shoe and adjusted in conformance with Table O‑10.
• Employers should document who is authorized and provide training so adjustments are made safely and correctly.

Acceptable point of operation devices include devices that stop or prevent the press stroke if hands are in the point of operation, prevent reaching into the point of operation, require both hands on controls located a safe distance away, enclose the point of operation before a stroke is initiated and until motion stops, or otherwise prevent reaching in before die closure. See 1910.217(c)(3)(i).

• Examples given in the standard: presence sensing protective devices, pull‑out devices, restraint devices, two‑hand controls, and enclosures (1910.217(c)(3)).
• The selected device must reliably protect the operator in the manner described by the specific subparagraph that applies (e.g., preventing or stopping a stroke if hands are in the point of operation).

A Type A gate or movable barrier device must enclose the point of operation before a press stroke can be initiated and maintain the closed condition until slide motion has ceased, while a Type B gate or movable barrier device must prevent the operator from reaching into the point of operation prior to die closure or prior to cessation of slide motion. See 1910.217(c)(3)(ii)(a) and 1910.217(c)(3)(ii)(b).

• Type A corresponds to the protection described in 1910.217(c)(3)(i)(f); Type B corresponds to 1910.217(c)(3)(i)(g).
• Employers must choose the gate type that provides the required protection for the operation being performed.

No—presence sensing point of operation devices may not be used on machines with full‑revolution clutches, and they may not be used to initiate slide motion except when used in total conformance with paragraph (h) of the section. See 1910.217(c)(3)(iii)(a) and 1910.217(c)(3)(iii)(b).

• Presence sensors must also be interlocked into the control circuit to prevent or stop slide motion if a body part is in the sensing field during the downstroke (1910.217(c)(3)(iii)).
• If you consider using a presence sensing device as a tripping means, consult the requirements in paragraph (h) to ensure full compliance.

A presence sensing device must be constructed so that a failure does not prevent the normal stopping action being applied when required, but does prevent initiation of a successive stroke until the failure is corrected, and the failure must be indicated by the system. See 1910.217(c)(3)(iii)(c).

• In practice, this means the device must fail safe: it must allow the press to stop if necessary but block restarting and provide a visible or audible indication of the fault.
• Employers should ensure maintenance and testing procedures detect and correct such failures before returning the press to normal operation.

The minimum safety distance (Ds) is calculated using the formula Ds = 63 inches/second × Ts, where Ts is the stopping time of the press measured at approximately 90° position of the crankshaft. See 1910.217(c)(3)(iii)(e).

• Use 63 inches/second as the hand speed constant.
• Measure Ts (in seconds) as the machine’s stopping time at roughly 90° crankshaft position; multiply to get Ds in inches and place the sensing field at least that distance from the point of operation.

Pull‑out devices must protect the operator by preventing reaching into the point of operation, include attachments for each of the operator's hands, and those attachments must be connected to and operated only by the press slide or upper die. See 1910.217(c)(3)(iv) and 1910.217(c)(3)(iv)(a).

• Each operator must have an attachment; separate pull‑out devices are required when more than one operator is used.
• Attachments must be mechanically linked to the slide/upper die so operators cannot circumvent protection.

Each pull‑out device in use must be visually inspected and checked for proper adjustment at the start of each operator shift, after a new die set‑up, and when operators are changed; required maintenance or repairs must be completed before operation, and records of inspections and maintenance must be kept as required by paragraph (e). See 1910.217(c)(3)(iv)(d) and 1910.217(c)(3)(iv).

• Inspections are required at shift start, after die set‑up, and when operators change.
• Keep inspection and maintenance records in accordance with 1910.217(c)(3)(iv)(d) and paragraph (e) of the standard.

When a press operation requires more than one operator, separate two‑hand controls must be provided for each operator and designed so all operators must apply their controls concurrently to activate the slide; removal of a hand from any control must stop the slide. See 1910.217(c)(3)(vii)(a).

• Each two‑hand control must also meet the construction requirements in 1910.217(b)(7)(v).
• The safety distance (Ds) between each two‑hand control and the point of operation must be greater than Ds = 63 inches/second × Ts as specified in 1910.217(c)(3)(vii)(c), and the controls must be fixed in position except by a supervisor or safety engineer (1910.217(c)(3)(vii)(d)).

The safety distance (Dm) between a two‑hand trip and the point of operation is Dm = 63 inches/second × Tm, where Tm is the maximum time the press takes for die closure after tripping. For full‑revolution clutch presses with one engaging point, Tm equals the time for one and one‑half revolutions; for presses with more than one engaging point, Tm = [½ + (1 ÷ Number of engaging points per revolution)] × time to complete one revolution. See 1910.217(c)(3)(viii)(c).

• Use 63 inches/second as the hand speed constant and measure Tm in seconds to compute Dm in inches.
• Two‑hand trips must also be fixed in position so only a supervisor or safety engineer can relocate them (1910.217(c)(3)(viii)(d)).

No—hand feeding tools are not point of operation guards or protection devices and must not be used in place of the guards or devices required by the standard. See 1910.217(c)(4).

• Hand feeding tools are intended only for placing and removing materials and cannot substitute for required guarding or safety devices.
• Employers should use the guards or point of operation devices specified in 1910.217(c) when feeding materials by hand.

When the operator places one or both hands in the point of operation and safeguarding relies on a two‑hand control, presence sensing device, Type B gate, or a movable barrier on a part‑revolution clutch, the employer must use a control system and a brake monitor that comply with 1910.217(b)(13) and 1910.217(b)(14). See 1910.217(c)(5)(i).

• The exceptions for older two‑hand controls or controls installed before August 31, 1971, do not apply in this context (1910.217(c)(5)(ii)).
• For air‑clutch machines with part‑revolution clutches, controls must prevent a significant increase in stopping time due to operating valve failures and must inhibit further operation if such a failure occurs (1910.217(c)(5)(iii)).
• See 1910.217(b)(14) for specific brake monitor requirements.

A brake monitor used with a Type B gate or movable barrier device must detect slide top‑stop overrun beyond the employer's normal limit, be installed so it indicates when brake performance has deteriorated as described in [1910.217(b)(14)(i)], and be constructed and installed to monitor brake performance on each stroke. See 1910.217(b)(14)(ii) and 1910.217(b)(14)(iii).

• The monitor must detect overruns beyond the normal limit reasonably established by the employer and provide an indication when braking performance deteriorates.
• Brake monitor performance must be checked and maintained so it reliably monitors each stroke; integrate monitoring into the machine's control system as required by 1910.217(b)(13).

The employer must furnish and enforce the use of hand tools that let employees free and remove stuck work or scrap without reaching into the point of operation. This is required by 1910.217(d)(1)(ii).

• Use suitable long-handled or purpose-designed tools (hooks, push/pull tools, air or pressure guns where appropriate) so hands never enter the danger area.
• Provide and enforce training so operators and diesetters know which tools to use and the safe method to remove stuck parts (see employer training obligations in 1910.217(f)(2)).
• Use the supplementary tools listed in the standard — for example, brushes, swabs, lubricating rolls, and pressure guns — so lubrication or cleanup does not require reaching into hazard areas, as required by 1910.217(d)(9)(v).

Simple checks: if an operator can reach the die clearance line with fingers when the press is running or could be energized, change the procedure or tool until reaching is impossible.

Safety blocks must be provided and used whenever dies are being adjusted or repaired in the press. This requirement is stated in 1910.217(d)(9)(iv).

• Select safety blocks that can securely support the slide or die at the required opening and that are rated for the press and die weight.
• Combine safety blocks with positive energy control measures: stop the press, isolate power, and apply lockout/tagout before placing or removing blocks in accordance with your lockout/tagout procedures (see 1910.217(e) for inspection/maintenance responsibilities).
• If temporary re-energization is needed for testing or positioning during setup, follow the controlled sequence the Lockout/Tagout standard allows (clear tools and materials, remove employees from hazard areas, remove LOTO devices as required, energize briefly while protecting employees, then de-energize and reapply LOTO), consistent with OSHA’s guidance on temporary re-energization in the minor servicing exception context, see OSHA’s interpretation at https://www.osha.gov/laws-regs/standardinterpretations/2024-10-21.

Enforce use of safety blocks in procedures and training and verify their use during supervision and audits.

The employer must run a two-part inspection program: a general component of periodic inspections for the whole press and a directed component of regular (at least weekly) inspections and tests specifically of the clutch/brake, antirepeat feature, and single-stroke mechanism, and must keep certification records as required. These requirements are in 1910.217(e)(1)(i) and 1910.217(e)(1)(ii).

• General component (periodic and regular): inspect all parts, auxiliary equipment, and safeguards (including clutch/brake, antirepeat, single-stroke); complete maintenance or repairs before operating; keep a certification record with date, signature of inspector/repairer, and the press serial number as required by 1910.217(e)(1)(i).
• Directed component (at least weekly): inspect and test each press weekly for the clutch/brake, antirepeat, and single-stroke; complete needed maintenance before operating; maintain a certification record of each maintenance task for the directed component with date, signature, and press identifier per 1910.217(e)(1)(ii).
• Note the standard’s recordkeeping nuance: inspections of those components performed under the directed component are exempt from some record requirements that apply to the general component, but inspections under the general component are not exempt (see the Note to 1910.217(e)(1)(ii)).

Keep inspection and repair records organized and accessible by press identifier so you can demonstrate compliance during audits or enforcement visits.

Dies must be stamped (or have readily available written records) with tonnage and stroke requirements, stamped to indicate upper die weight when needed for air counterbalance adjustment, and stamped to indicate complete die weight when handling equipment could be overloaded. These requirements are in 1910.217(d)(6)(i)-(iii).

• Purpose: stamping/recording ensures die setters and press operators know the die’s required tonnage and stroke so the press is not overloaded or improperly adjusted.
• Upper die weight stamping helps set correct air counterbalance pressure so the slide operates safely.
• Complete die weight stamping prevents overloading of handling equipment and provides safe limits for lifting or turnover operations; also provide handling attach points as required by 1910.217(d)(8).

Ensure die markings are legible and records are kept where die setters can access them before mounting or handling a die.

PSDI may be used only on part-revolution mechanical power presses and only where the sensing field cannot be entered and the press meets the other requirements of paragraph (h); full-revolution presses and any press whose configuration allows a person to enter the sensing field into the hazardous portion are excluded. See 1910.217(h)(1)(i), (iii), and (iv).

• PSDI applies only to part-revolution presses in PSDI mode (1910.217(h)(1)(i)).
• Full-revolution presses are forbidden for PSDI use (1910.217(h)(1)(iii)).
• A press whose layout would permit a person to pass through the sensing field and enter the hazardous portion of the press may not use PSDI (1910.217(h)(1)(iv)).
• Remember: presses in PSDI mode must still comply with the relevant parts of paragraphs (a) through (g) and PSDI is intended for normal production operations only; die-setting and maintenance must not be done in PSDI mode (1910.217(h)(1)(ii) and (v)).

Before using PSDI, verify press type, guarding layout, and brake/clutch requirements in 1910.217(h)(2) to ensure safe stopping performance.