Match hole saw sizes to pipe outside diameters for copper, PVC, and PEX. Ensures proper clearance for plumbing runs through framing.
Doing this on a real job? Replace a faucet or sink: materials, tools and steps sized to your numbers.
Get the planImportant: Pipe sizes are nominal (trade names), not actual outside diameters
Clearance: Holes should be slightly larger than pipe OD for easy installation and to avoid fire/moisture barrier damage
Always verify actual pipe outside diameter before drilling - manufacturers may vary slightly.
| Nominal Size | Actual OD | Hole Saw Size | Typical Use |
|---|---|---|---|
| 3/8" | 0.500" | 3/4" | Ice maker, small fixtures |
| 1/2" | 0.625" | 7/8" | Supply to fixtures |
| 3/4" | 0.875" | 1-1/8" | Main lines, branches |
| 1" | 1.125" | 1-3/8" | Main service lines |
| 1-1/4" | 1.375" | 1-5/8" | Commercial, large homes |
| 1-1/2" | 1.625" | 1-7/8" | Commercial supply |
| Nominal Size | Actual OD | Hole Saw Size | Notes |
|---|---|---|---|
| 3/8" | 0.500" | 3/4" | Ice maker, small runs |
| 1/2" | 0.625" | 7/8" | Most fixture connections |
| 3/4" | 0.875" | 1-1/8" | Trunk lines, manifolds |
| 1" | 1.125" | 1-3/8" | Main lines |
PEX has same OD as copper of the same nominal size
| Nominal Size | Actual OD | Hole Saw Size | Typical Use |
|---|---|---|---|
| 1-1/4" | 1.660" | 1-7/8" or 2" | Lavatory drain |
| 1-1/2" | 1.900" | 2-1/8" | Sink, tub drain |
| 2" | 2.375" | 2-5/8" or 2-3/4" | Shower, multiple fixtures |
| 3" | 3.500" | 3-3/4" or 4" | Toilet, main stack |
| 4" | 4.500" | 4-3/4" or 5" | Building drain, sewer |
| Trade Size | Actual OD | Hole Saw Size | Wire Capacity |
|---|---|---|---|
| 1/2" | 0.706" | 7/8" | 3-4 #12 THHN |
| 3/4" | 0.922" | 1-1/8" | 4-5 #12 THHN |
| 1" | 1.163" | 1-3/8" | 6-8 #12 THHN |
| 1-1/4" | 1.510" | 1-3/4" | Multiple circuits |
| 1-1/2" | 1.740" | 2" | Service entrance |
| 2" | 2.197" | 2-1/2" | Large service |
| Nominal Size | Actual OD | Hole Saw Size | Notes |
|---|---|---|---|
| 1/2" | 0.840" | 1-1/8" | Appliance connections |
| 3/4" | 1.050" | 1-1/4" | Branch lines |
| 1" | 1.315" | 1-1/2" | Main supply lines |
| 1-1/4" | 1.660" | 1-7/8" | Larger homes |
⚠️ Gas work typically requires licensed plumber and inspection
Fire Stopping
Moisture Barriers
Best Practices
Speed: Slower RPM for larger hole saws, faster for smaller
Pressure: Let the tool do the work - excessive pressure dulls teeth
Pilot Bit: Ensure pilot bit is in good condition for accurate holes
Clearing: Back out periodically to clear chips
Material: Bi-metal for wood/metal, carbide for masonry
Arbor Compatibility:
Drilling the correct hole size for pipes is critical - too small and you'll damage the pipe forcing it through, too large and you'll have excessive air leakage or difficulty sealing. The confusion arises because pipe sizes are nominal (trade names), not actual outside diameters. A 1/2" copper pipe actually measures 0.625" OD, requiring a 7/8" hole saw.
This guide provides hole saw sizes for all common pipe types: copper supply lines, PEX tubing, PVC/ABS drain pipes, EMT electrical conduit, and black iron gas pipes. Each table shows the nominal pipe size, actual outside diameter, and recommended hole saw size with enough clearance for easy installation and proper sealing.
Whether you're running plumbing through studs, drilling through top plates for vents, or creating penetrations through fire-rated assemblies, this reference ensures you drill the right size hole the first time and understand the clearance requirements for proper installation.
Drilling wrong-sized holes wastes time, damages materials, and complicates installations. This guide eliminates guesswork and ensures proper clearances for all pipe types.
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