If you have ever talked to a handyman or basically anyone who is into DIY- they will tell you that the hole saw is their magic do-it-all tool. With low power consumption and their relatively cheap prices, hole saws are perfect for almost any task. However, using the correct size and proper maintenance is detrimental to ensuring success.
The reason hole saws usually stand out from drill bits is because of their precision and job flexibility. This means hole saws provide a cleaner finish due to their pilot bits that allow you to be bang on with the size of the hole. If done correctly, a hole saw will almost always allow you to avoid splintering.
And that is what this article is all about- providing you with an easy access list that allows you to choose the right size hole saw for a neat, clean, and precise finish. Our size chart is made with recommendations from industry experts and with NEMA recommendations in mind.
Electrical Conduit Hole Saw Sizes with Knockout Punch Equivalent
| Conduit Size | Hole Saw Size (NEMA recommended) | Knockout Punch |
| ½ Inch | ⅞ Inch or 22 mm | 0.885 Inches or 22.5mm |
| ¾ Inch | 1 ⅛ Inch or 29 mm | 1.115 Inches or 28.3 mm |
| 1 Inch | 1 3/8 inches or 35 mm | 1.362 Inches or 34.6 mm |
| 1 ¼ Inches | 1 ¾ Inches or 44 mm | 1.701 Inches or 43.2054 mm |
| 1 ½ Inches | 2 Inches or 51 mm | 1.951 Inches or 49.6 mm |
| 2 inches | 2 ½ Inches or 64 mm | 2.416 Inches or 61.3664 mm |
| 2 ½ Inches | 3 Inches or 76 mm | 2.914 Inches or 74 mm |
| 3 Inch | 3 ⅝ inches or 92 mm | 3.539 Inches or 89.9 mm |
| 3 ½ Inch | 4 ⅛ Inches or 104 mm | 4.044 Inches or 102.7 mm |
| 4 inches | 4 ½ Inches or 114 mm | 4.544 inches or 115.4176 mm |
| 5 inches | 5 ½ Inches or 140mm | N/A |
| 6 Inches | 6 ⅝ Inches or 168 mm | N/A |
Hole Saw Size Recommendations for Domestic Maintenance
Dryer vent:
Most Dryer Vents are 4 inches in diameter. This means the hole in the vent opening needs to be approximately 4 and ¼ Inches and that is the correct hole saw size. Once the hole saw’s pilot goes through to the other side, it is important to switch sides to complete the hole using pilot opening as a guide. For proper maintenance, frequently cool your hole saw and ensure that debris or junk is not building up.
Bathroom Vent:
Before attaching the exhaust duct to the wall cap, an opening is to be made in the duct through the house wall. The accurate tool bit for this operation is a 4 Inch hole saw.
Electrical Box:
For a tight and clean fit into drywall, use a 4 Inch hole saw for electrical boxes. This size may vary to 3.5 Inches if you are drilling through wood.
