Choose the bit size and the grid — 20 1/4" bits by default — and get a block of upright hex holes sized from the ISO 1173 shank, 10 mm deep with an entry chamfer. Stand it on the bench, drop it into a Gridfinity baseplate, or screw it to the wall or a pegboard. The hole clearance is a setting because printers differ.
The real generator runs in your browser: set the parameters, then download STEP or STL. Nothing to install, no sign-up.
The first open downloads the CAD engine (about 20 MB).
Each parameter below rebuilds real geometry on every change — this is parametric CAD, not a scaled mesh.
| Parameter | Default | Range | What it does |
|---|---|---|---|
| Bit shankBIT_SIZE | 1/4in | 4mm / 1/4in / 5/16in | Hex shank across flats per ISO 1173: 3.96 / 6.35 / 7.93 mm. |
| Hole clearanceCLEARANCE | 0.15 mm | -0.1 – 0.6 | Added across flats; 0.15 is the median of published holders. |
| Hole depthDEPTH | 10 mm | 6 – 20 | How deep each bit sits, over a 2 mm floor. |
| ColumnsCOLUMNS | 5 | 1 – 10 | Bits per row. |
| RowsROWS | 4 | 1 – 8 | Up to 80 bits in one block. |
| Wall between holesGAP | 2 mm | 1.2 – 6 | More gap = easier to grip a bit. |
| PatternPATTERN | square | square / staggered | Square grid or staggered (honeycomb) rows. |
| MountMOUNT | none | none / gridfinity / wall | Free-standing, Gridfinity feet, or a screw plate on the 25 mm pegboard pitch. |
Every parameter can go in the page's link, so one link opens exactly the part you want. Example (24 bits on a wall / pegboard plate):https://www.forgent3d.com/en/generators/hex-bit-holder-generator?MOUNT=wall&COLUMNS=8&ROWS=3
STEP AP214 in millimetres, exact B-rep — it opens directly in SolidWorks, Fusion, FreeCAD, Onshape or Inventor, and goes straight into a CNC quote form. STL for the slicer is one click too.
| This generator | Typical online STL generator | Vendor CAD library | |
|---|---|---|---|
| Any size within the range | Yes | Yes | Catalog sizes only |
| STEP with exact surfaces | Yes | Usually an STL mesh only | Yes |
| Changes the sliders don't cover | “AI edit” on the page | No | No |
| Account needed to download | No | Usually no | Often |
Every parameter is a link parameter; the link below opens the example part. ChatGPT, Claude or any assistant can write one like it from the parameter list (names, units, ranges) at: parameter list (JSON)
Example: https://www.forgent3d.com/en/generators/hex-bit-holder-generator?MOUNT=wall&COLUMNS=8&ROWS=3
Press “AI edit” in the generator and say what to change — a keyway, holes, a different shape. The AI edits the part's model.py and it rebuilds in your browser, with undo. A few edits a day are free without signing in; to keep the result or go further, copy it into your models and continue with the AI agent.
Edit with AI →For bigger changes, several rounds, or a part you want to keep: copy it into your models (free account). The Forgent3D AI agent reads the model.py, edits it, rebuilds it and checks the result itself.
Copy and continue with the AI agent →That depends on your printer: holes that held bits for other makers range from 6.25 to about 6.9 mm across flats, and one maker found 6.5 mm too loose. The default is 6.35 + 0.15 = 6.5. Print a small block first and move the clearance in 0.05 mm steps.
Yes. Insert bits are 25 mm long and power bits 50, 70 or 90 mm (Bosch, Wiha, Vessel, DeWalt), but they share the same 1/4" hex shank, so they sit in the same holes — the long ones just stand taller.
Countersunk wood screws of about 3.5 mm (#6): the plate has 3.9 mm holes with 8.3 mm countersinks, 25 mm apart to match pegboard.
Open https://www.forgent3d.com/en/generators/hex-bit-holder-generator?MOUNT=gridfinity — 20 upright hex holes spread over a 2 × 1 Gridfinity block with the same feet as our Gridfinity bins, so it drops into a standard baseplate. Change COLUMNS and ROWS for more or fewer bits.
The hole clearance: printers differ, and holes that worked for other makers range from 6.25 to about 6.9 mm across flats for 6.35 mm bits. Print a three-hole tester first — https://www.forgent3d.com/en/generators/hex-bit-holder-generator?COLUMNS=3&ROWS=1&CLEARANCE=0.05 — and move CLEARANCE in 0.05 mm steps until a bit holds.
Yes. Models you generate and the STL / STEP files you export are yours: print them, sell the prints, or use them in a product. No attribution to Forgent3D is required.
Already have your own .scad file? Convert OpenSCAD to STEP → · Preview it in the browser →
