Central Manual Knockout Punch Kit

I'm not an electrical engineer - I'm a computer engineer. I am a PC moding hobbyist. I purchased these punches because I wanted to make various size holes in PC cases in order to accomodate reseviors and flexible tubing. Some cases have immovable parts (Drive cages for example) that I would rather go through than around. Shopping for knockout punches I found them to be expensive - a set from a different vendor was over 150 dollars - so these seemed reasonable at about 50.00. Again, I'm NOT an electrical engineer. I'm just trying to punch round uniform holes in thin metal associated with a PC case. These punches worked very well for that purpose and came in exactly the sort of sizes I needed. I'm giving 5 stars but I'm not using them in a typical way I suppose.There are a couple things to note for the novice (and I'm definitely a novice with these tools). First the pilot hole you drill must be 1/2 an inch - that's a fairly big drill bit so be prepared. Second, you need a 1 inch wrench (pipe or rachet) - and that is a fairly big wrench. If you have typical household tools and are not a car guy or DIY handyman you may not have these lying about - so be prepared to ask to borrow one from that guy you work with who has that truck seemingly full of spare tools.

I bought these because I've misplaced my Greenlee knockout set and didn't want to spend a fortune. They arrived earlier than expected and they produced a mostly clean hole. A small area about 3/8 inch long (around the outside of the 1/2 conduit hole) was not perfectly cut and had a lip, but 20 seconds with a file and it was clean. I would recommend this set to a friend.

lo compre para horadar laminas plasticas, aluminio y hierro delgado. <si note que de los dos tornillos el grande para 3/4 1 y 1/1/4 tiene la cabeza fija mientras que el tornillo para 1/2 la cabeza es movil. aun no entiendo porque tiene ese diseño. considero que es una desventaja pues mientras pamsa partes moviles en conciiones de torque, mas facilidad hay para degastes y fricciones que deterioran la herramienta. Sin embargo el precio es excelente y la muela que perfora es de 4 contactos en vez de 2 contactos, posiblemente eso lo haga mas eficiente..

These are not Greenlee punches by any stretch of the imagination. These are, however, punches that make nice holes in metal chassis. The hole's edges are round, but sometimes there is a metal rise outside the hole diameter that needs cleaning off to get a tube socket to lay flat. For the price, they are fine for hobbyists, tinkerers, and restorers. This set provides a nice assortment of hole sizes to choose from.

1/2" knockout out works, but the fit between the die and cutter is so poor on the 3/4", it doesn't cut the metal. The two largest sizes have tight tolerances and seem like they would work. It's only the 3/4" size that is junk.

The very next day after I received this set I was using it. I had 1 1/4" conduit that I needed to make some holes for. I have already used it 5 times. The holes where cut smooth with no rough edges. All my holes were a perfect match to my conduit. This is a great set for occasional use. If you would need it more often I would suggest hydraulic set it will make your arms tired.

Worked OK for what I needed. Just had to use the smallest punch. Would be nicer if there were more smaller sizes available as I don't think I would ever need any of the larger sized punches but I can see needing something in between the smallest and the next couple of sizes up.I had to punch holes in some sheet aluminum panels for XLR microphone connectors. This was much easier than trying to drill and enlarge by hand.

I found that the information provided on the website and on the packaging was in conflict with each other and the actual pieces in the kit. I supposed that's what I should expect for buying relatively inexpensive tools. As the old adage said, "you get what you pay for".To begin, I was confused as to the difference between a punch and a die, since both words seemed to be used interchangeably. But according to the tool kit "Owner's Manual" booklet, the die was the external part, and the punch was the internal part, as it fitted into the die.But according to the specifications I obtained from the re-seller's web-page, those punch and die sizes were ridiculous. For example, a (½") die was smaller than the mating punch size (7/8").Furthermore, the "Owner's Manual" booklet stated in the part description table that the kit contained a (½") punch for a (½") die, a (¾") punch for a (¾") die, a (1") punch for a (1") die and a (1-¼") punch for a (1-¼") die. Those sizes were all wrong because the punch had to be smaller by a small tolerance to fit into the die.I then measured the smallest punch and die pair, only to find out that there was nothing in the kit even closely related to (½"). The smallest punch had an OD of (7/8") (~22 mm), with the corresponding die being slightly larger; that pair could be used to create the pass-through holes for the extender fittings.However, that wasn't the last of it. The "Owner's Manual" booklet stated that the smaller drive bolt required a (½" dia.) hole. I therefore drilled the required hole-size to only find out that it was too large, as it would have too much play in centering the bolt in the hole. That discovery alone made it seem that this was not a tool for precision work. I then measured the thread outer diameter of the drive bolt, which was (~7/16") (~11 mm).