OSHA CFR 1910.217(d)(9)(iv) addresses safety blocks“(iv)

The employer shall provide and enforce the use of safety blocks for use whenever dies are being adjusted or repaired in the press”

1. It’s required by ANSI (American National Standards Institute)

2. It’s safer; if the safety block is interlocked and forgotten in the press after the work is completed, the press can’t move and no projectile will be expelled from the press.

 

This means the interlocked safety block not only protects personnel but also the machine/ die(s).

9.2.6 Die adjustment, cleaning and repair

 

1.“When it is necessary to place hands or other body parts into the point of operation for repair with the die(s) in the press or adjustment and cleaning which is not integral to the production process, means shall be provided to prevent the initiation of hazardous movements.”

 

2. Safety blocks or other die/ slide support means (e.g., slide locks, chain locks, locking pins) that restrict hazardous motion shall be designed constructed, and installed to either:

 

a) Hold the full working force of the machine and tooling members when machine actuation can take place while the mechanism is in place; or

b) Be interlocked with the machine to prevent actuation of hazardous motion of the machine while in place in its protecting position and be designed and constructed to hold the maximum anticipated load (normally the static weight of the movable portion of the machine, its tooling, and attachments.

 

3. Electrical interlocking of manually installed safety block(s) or other die slide support means shall automatically de-energize the clutch and drive motor circuits when safety blocks are removed from their storage locations.