Why a taller strip
Driver bits come in two common lengths. Insert bits are 25 mm long and are meant for a magnetic holder. Power bits are 50 mm long, with a groove near the end, and go straight into the chuck of an impact driver. A strip with 10 mm pockets holds the short kind well, but a 50 mm bit standing in it has four fifths of its length in the air and falls over at the first knock, taking its neighbours along. This page raises the strip to 20 mm over a 2 mm floor. The pockets are then 18 mm deep, a little over a third of a power bit, and the bit stands 32 mm above the strip: steady, and with plenty to hold.
What to measure
Measure across two opposite flats of a bit; power bits are 6.35 mm like any standard hex bit. Then check the length of what you own. If the set is mixed, sort it: 25 mm insert bits dropped into 18 mm pockets leave only 7 mm showing, which is too little to grip, so they belong in a lower strip. Measure the space as well. The strip is 79.8 by 13.6 mm, and with 50 mm bits in place the whole thing stands 52 mm high, which rules out most shallow drawers and suits a shelf or a deep tool case.
Clearance, walls and material
The pocket clearance is 0.25 mm, giving 6.6 mm across flats. A deep pocket grips over more length than a shallow one, so the same clearance feels tighter here: if bits stick on the way out, go to 0.3 mm. The walls between pockets and around them are 3 mm. A tall narrow strip, 20 mm high on a base 13.6 mm deep, is easier to knock over than a low one. If it will stand loose on a bench, raise the wall around the pockets to 6 mm, which widens the base to 19.6 mm, or fix the strip down with tape or two small screws through the end walls.
Printing
Print flat with the pockets facing upwards, as generated, and no supports. Deep narrow pockets are where stringing collects, and a wisp of plastic at the bottom of a pocket stops a bit seating fully, so print PLA at the cool end of its range with retraction on, and look down each pocket against the light afterwards. Three perimeters at 0.2 mm layers are enough. The strip takes about an hour.
Outline drawing
To scale. Pocket centres are 9.6 mm apart; the first and last pockets are 3 mm from the ends.
Parameters the generator will use
| Setting | Link parameter | Value |
|---|---|---|
| Model | model | bit_holder |
| Bits per row | count | 8 |
| Rows | rows | 1 |
| Bit size across flats | across_flats | 6.35 |
| Pocket clearance | clearance | 0.25 |
| Wall between pockets | gap | 3 |
| Wall around the pockets | margin | 3 |
| Strip height | height | 20 |
| Floor under the pockets | floor | 2 |
All lengths are in millimetres. Outer size from these values: about 79.8 x 13.62 x 20 mm.
Open the generator with these values
This model needs the $7 licence key: one payment, one key, and it opens all five paid models. Get a licence key on Gumroad ($7)
The hex bit holder strip needs a licence key: without one the generator shows the model locked, lists the values from this link and fills them in as soon as you unlock. The fitted drawer organiser bin is the free model and downloads with no key.