The 7 Best Knockout Punches
This wiki has been updated 12 times since it was first published in July of 2019. Powered by hydraulic pumps, lithium-ion batteries or just good-old-fashioned elbow grease and determination, knockout punches drill smooth holes into steel electrical cabinets, allowing the boxes to accommodate new conduits. Our rankings in this category cover a range of options suitable for various budgets – from ratcheting manual options all the way up to modern electric models. When users buy our independently chosen editorial picks, we may earn commissions to help fund the Wiki. If you'd like to contribute your own research to the Wiki, please get started by reviewing this introductory video.
August 30, 2019:
Although some options are rated to cut through aluminum, fiberglass and plastics, the primary purpose of a knockout punch is to cut smooth holes into steel electrical cabinets, allowing the box to accept new raceways. While they all operate on the same working principle, there are three basic styles of tool in this category. Note that when it comes to these tools, cost and convenience factor are directly proportional.
Ratcheting Style options are the most basic tools in this category, depending on sheer tricep muscle and elbow grease to wrench dies through steel. While there are still veterans in the electrical world who will swear by longevity and dependability of these units, their operation is undeniably time consuming and arduous.
Hydraulic Pump options are a major step up from their manual alternatives. Some manufacturers claim that their hydraulic models can get the job done 10 times faster than wrench-based options. The downside to these models is how heavy they are, and the messy maintenance that inevitably comes with changing gaskets and hydraulic fluid.
Battery-Powered options are still a relatively new novelty available to contractors. Pricey as they may be, it’s tough to beat their compact, lightweight design and speedy operation.