Knockout Punch Selection Guide

Knockout Punch Selection Guide

Not to be confused with a K.O. in boxing, a knockout tool is used to cut holes in sheet metal. All punch tools operate in a similar manner, and consist of three main parts: the draw stud, punch, and die.

General Operation

1. Drill a properly sized pilot hole. The diameter of the draw stud will determine the size of the drill bit you will need to use for the pilot hole. This first step is the most important since the location and size of the pilot hole will determine the location and quality of the knockout.

2. Slide any spacers and the die onto the draw stud.

3. Insert the draw stud until the die lies flat against one side of the sheet.

4. Screw the matching punch onto the stud on the other side of the sheet.

5. Draw the punch through the sheet metal and into the die.

TEMCo Knockout Punch

Selecting a Punch Tool

There are two basic specifications to consider: what materials can be punched through and what size holes can be made. The size and shape of the holes will depend on the punch and die sets included in the knockout kit.

Manual Manual punches are cheap but take more effort to use and are not as powerful as other types of knockout tools. These types of punches may use a wrench or a ratcheting mechanism to draw the punch into the die.

Hydraulic Hydraulic punches are much more powerful, easier to use, and can be used on thicker gauges of sheet metal.

Operating a Hydraulic Knockout Punch

Knockout Punch Step 1

Step 1

Install the correct punch mandrel on the hydraulic cylinder along with the female portion of the punch die.

Knockout Punch Step 2

Step 2

Drill a pilot hole large enough to clear your selected punch mandrel.

Knockout Punch Step 3

Step 3

Insert the punch mandrel through your drilled hole in the panel. Install the male portion of the punch die by threading it down to the point where it is snug against the metal to be punched.

Knockout Punch Step 4

Step 4

Close pump valve and pump the handle until the punch is drawn through the metal. Release the pump valve and remove the punch dies.

Product Selection


Part # Punch Type Punching Force Punches Materials Punch Dies Included Punching Thickness Capacity
Carbon Steel Stainless Steel
TH0004 Hydraulic 9 US Tons (18000 lbs.) Steel, Stainless Steel, Brass, Copper, Aluminum, Fiberglass Plastic ½", ¾", 1", 1 ¼", 1 ½", 2" 0.125" 0.0625"
TH0037 13 US Tons (26000 lbs.) 1/2", 3/4", 1", 1 1/4", 1 1/2", 2", 2 1/2", 3", 3 1/2", 4"