What are knockout tools?
Knockout tools—also called knockout punches—are a single-purpose tool designed to make clean, round, conduit-size holes in electrical boxes and panels. Once, this task was performed by drilling a small hole and reaming it to the required size.
What is a knockout punch set for?
A knockout punch, also known as a chassis punch, panel punch, Greenlee punch, or a Q-max, is a hand tool used to punch a hole through sheet metal. It is a very simple tool that consists of a punch, die, and screw. There are three different drive systems: manual, ratchet, and hydraulic.
Can you use a knockout punch on plastic?
There are also heavy-duty knockout punches that use a hydraulic pump, but these are overkill for most residential wiring. Most punches will cut through mild steel up to 10 gauge, plus stainless steel, plastic, and fiberglass.
What is an electrical knockout?
Knockouts are the places where an electrical box has been punched through to allow for wiring, so connections for outlets, light fixtures or additional wiring can be made within the box, which is rated to resist fire if anything overheats.
What size are electrical knockouts?
Stimpson offers Electrical Knockout Plugs in six basic sizes: 1/2”, 3/4”, 1”, 1-1/4”, 1-1/2”, and 2”. Variations for special situations are also available.
How do you knock out a hole in a metal electrical box?
To remove a knockout, position the tip of a regular, blade-tip screwdriver just inside the edge, on the side opposite the attachment points. That ought to partially dislodge the knockout, allowing you to remove it the rest of the way by twisting back and forth until the attachment points snap.
What size Knockout do I need?
How do I know what size to order?
| Standard Conduit or Pipe Size (I.D.) | Actual O.D of Pipe | Actual Hole Size |
|---|---|---|
| 1/2″ | 0.840″ (21.33mm) | 0.875″ (22.22mm) |
| 3/4″ | 1.050″ (26.67mm) | 1.125″ (28.57mm) |
| 1″ | 1.315″ (33.40mm) | 1.375″ (34.92mm) |
| 1-1/4″ | 1.660″ (42.16mm) | 1.734″ (44.04mm) |
What size is a 1/2 electrical knockout?
0.875 inches
The nominal knockout diameter for 1/2 inch conduit is 0.875 inches.
What size are knockouts on electrical boxes?
What size are electrical box knockouts?
What size is a 3/4 knockout?
1.109 inches
The nominal knockout diameter for 3/4 inch conduit is 1.109 inches.
What size is a 1/2 knockout?
How do I know what size to order?
| Standard Conduit or Pipe Size (I.D.) | Actual O.D of Pipe | Actual Hole Size |
|---|---|---|
| 1/4″ | 0.540″ (13.72mm) | 0.575″ (14.61mm) |
| 3/8″ | 0.675″ (17.15mm) | 0.718″ (18.24mm) |
| 1/2″ | 0.840″ (21.33mm) | 0.875″ (22.22mm) |
| 3/4″ | 1.050″ (26.67mm) | 1.125″ (28.57mm) |
What should you do if there are unused openings in a panelboard?
There are only two feasible means to fill an unused opening in a panelboard. An identified blank from the manufacturer is one option. The most effective option is to install a spare circuit breaker. It is important to note that an unused opening for a conduit or cable assembly will result in the same citation.