Dear Mr. Electrician: What are the actual electrical conduit hole saw sizes for the various trade sizes of electrical conduit?
Answer: Electrical conduit hole saw sizes and knockout punch sizes for conduit are posted below.
NOTE: Some text links below go to applicable products on Amazon. As an Amazon Associate, I earn from qualifying purchases.
Electrical conduit hole saw sizes are not the exact dimensions as the trade name size of the conduit.
Table of Contents:
Drilling With A Hole Saw
Hole Saw Sizes and Knockout Punch Equivalent
Hole Sizes for Tapping Conduit Threads
Knockout Punch Operating Instructions
Greenlee Knockout Punch Replacement Part Numbers
DRILLING WITH A HOLE SAW
When drilling with a hole saw, it is important to use a slower-spinning drill with a lot of torque rather than a high-speed drill. It is best to drill at 400 revolutions per minute (RPM) or slower when using a hole saw.
Drilling at a slower speed will help the hole saw last longer, and there is less danger of getting jammed and causing damage or injury.
I usually use my 1/2" Milwaukee Electric Right Angle Drill when using a larger hole saw as the torque is very good, and the RPMs are just right. The extra length of the right-angle drill makes it easier to maintain control of the drill if the hole saw does get jammed.
I suggest wearing work gloves when using a right-angle drill. Some angle drills have an accessory handle to gain extra leverage and control when drilling. It is a good idea to use it.
When drilling into metal, it is a good idea to oil the hole saw a few times during the drilling process to prevent premature wearing of the hole saw teeth. I read in a trade magazine of one electrician who puts an oil-soaked cut-to-size piece of Felt inside his hole saws whenever he drills into metal. As the hole saw heats up from drilling, the oil will trickle down onto the drilled metal.
Put something on the floor to protect it from oil leaks, such as flattened boxes or an old piece of plywood. Although you can probably use most general-purpose oil or motor oils for lubricating when drilling, there are oils made especially for drilling, tapping, and threading. Amazon sells cutting oil which is used for these purposes.
At the bottom of this post is a list of old Greenlee hand knockout punch replacement part numbers that I scanned.
CLICK HERE to see Electrician's Hole Saw Kits on Amazon
The above photo depicts two types of hole saw arbors that are not interchangeable. The three arbors on the top left can only be used with a hole saw that has a rectangular, round shape. The others screw into one of two standard-size threads on hole saws with threads.
Top Of Page
HOLE SAW SIZES AND KNOCKOUT PUNCH EQUIVALENT
1/2″ conduit, drill using a 7/8″ or 22mm hole saw. 1/2" conduit knockout punch is 0.885" or 22.5mm.
3/4″ conduit, drill using a 1 1/8″ or 29mm hole saw. 3/4"...
Cookies are used on this website to give you the most relevant browsing experience by remembering your preferences and repeat visits. By clicking “Yes, I Agree”, you consent to the use of the cookies according to your choices in the Cookie Settings.
Third-party Cookies (Non-Necessary) that help analyze and understand how you use this website are utilized by advertisers. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. However opting out of some of these cookies may affect your browsing experience.
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.