Greenlee 7310SB 11-Ton Hydraulic Knockout Punch Kit
ELITE tier
Greenlee has been manufacturing knockout punches in Rockford, Illinois since before most electrical contractors were born — and the 7310 is the kit that defined the category.
Origin
Made in USA
Warranty
Lifetime limited warranty on punches, dies, and hand tools (original purchaser). 1-year limited warranty on hydraulic driver. All replacement parts available through Greenlee parts catalog.
Price
~$2026 (Heirloom)
The 11-ton hydraulic driver pushes hardened steel punches through 10-gauge mild steel with the kind of mechanical authority that cheap import sets can only approximate. Electricians on trade forums report units from the 1960s — and in one documented case, the 1930s — still cutting clean conduit holes without ever needing sharpening.
Every component is individually replaceable: punches, dies, draw studs, O-rings, hydraulic seals. Greenlee backs the punches and dies with a lifetime warranty and publishes full parts diagrams so nothing becomes a mystery.
At roughly two thousand dollars, this is not an impulse purchase. It is a career investment.
Over a 30-year professional span, that works out to about $67 per year for a tool that handles every knockout from half-inch to four-inch. The alternative — replacing cheaper sets every five to seven years — costs more and wastes more.
The 7310 is how knockout work was meant to be done.