Your Bearing, Magnet & Nut Pocket Size Calculator
Calculate 3D-print pocket sizes for bearings (608, 625, LM8UU…), round magnets, hex nuts and screw heads by printer type, fit and hole direction.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
Illustration. Open the tool for the real thing.
What is the Bearing, Magnet & Nut Pocket Size Calculator?
Designing a pocket for a 608 bearing, a 6 × 3 mm magnet or an M3 nut in a 3D-printed part always raises the same question: how big should the hole be? This calculator gives you the pocket diameter and depth for more than 30 common bearings (miniature, 6000/6200 series and LM-UU linear bearings), 22 round magnet sizes, and hex nut traps and screw-head counterbores for M2–M12, adjusted for your printing process (FDM, resin or SLS), the fit you want (press, snug, slip or loose), the hole direction and whether the pocket is covered.
It also shows the wall you need around the pocket, a bearing ledge so it cannot be pushed through, and notes for pausing the print to insert magnets. Because no calculator can know your printer, a button creates a fit-test coupon STL with five pockets in 0.1 mm steps around the calculated size — print it once, find the pocket that fits, and use that number from then on.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
Over 60 standard sizes plus custom entry.
FDM, resin and SLS, vertical or horizontal holes, press to loose fits.
Download a five-pocket STL stepped in 0.1 mm to calibrate your printer.
Ledges, cover layers, wall thickness and magnet polarity tips.
AZRS tools are free to open and use.
It opens in your browser, so there is nothing to download.
Used for
Pick one to see how it fits.
How it compares
A plain look at this tool next to the usual alternative.
| This maker tool | Desktop software | |
|---|---|---|
| Install | Nothing to install | Usually an app or program to install |
| Account | No signup | Depends on the product |
| Cost | Free to use | Free or paid, depends on the product |
| Where it runs | In your browser tab | On your computer |
Questions people ask
Are these values guaranteed?
No — they are common starting points; confirm with the coupon.
Why is horizontal larger?
Horizontal holes sag and print slightly undersized, so they need extra clearance.
Can I use my own sizes?
Yes, edit the diameter and thickness fields.
Is it private?
Yes, it all runs in your browser.
How do I use the Bearing, Magnet & Nut Pocket Size Calculator?
1. Pick the tab: bearings, magnets, or nuts and screw heads. 2. Choose the part, process, fit and hole direction. 3. Read the pocket size, depth and wall recommendations. 4. Print the fit-test coupon to confirm for your printer.
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Try the Bearing, Magnet & Nut Pocket Size Calculator now
Pocket and hole sizes for bearings, magnets, nuts and screw heads by printer and fit. Free to use.
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