Which half inch do you have
Inch pipe sizes are nominal: the name refers loosely to the bore, and the outside depends on the kind of pipe. Nominal 1/2 inch copper water tube, and the PEX and CPVC made to the same tube sizes, is 0.625 inch outside, which is 15.9 mm. That is the size this page builds. Nominal 1/2 inch iron pipe and schedule 40 PVC is 0.840 inch outside, 21.3 mm. Thin-wall electrical conduit of the 1/2 inch trade size is about 17.9 mm. And tube sold by its real outside diameter, such as aluminium tube, refrigeration tube or a wooden dowel, is 12.7 mm when it says half an inch. The spread from 12.7 to 21.3 mm is far more than any clip forgives.
What to measure
Measure the outer diameter, in millimetres, with a caliper, on a straight section away from fittings. If the reading is close to 15.9, use this page as it is. If it is near 21.3, 17.9 or 12.7, open the generator from the link below and replace the diameter with your reading; the other values on this page still suit pipes from about 12 to 22 mm. Note that 15 mm metric copper is nearly a millimetre smaller than this tube and rattles in a clip made for 15.9 mm, so the two are not interchangeable.
Clearance, wall and material
The clearance is 0.3 mm, giving a bore of 16.2 mm. That is a little generous for copper, which is round and accurate, and right for PEX, which is softer and often slightly oval after it has been coiled. The wall is 2 mm and the opening 95 degrees, so the gap is about 11.9 mm. PEX and copper water lines can run hot, and PLA softens at around 60 degrees C: print clips for hot lines in PETG or ASA, and keep PLA for cold lines and dry workshop use.
Printing and fixing
Stand the clip on a C-shaped face, layers around the pipe: about 34 by 17 mm on the bed and 12 mm tall, with no supports. Three perimeters at 0.2 mm layers fill the 2 mm wall. The tab is 14 mm long and 3 mm thick with a 4.2 mm hole, which takes a number 8 wood screw or a 4 mm screw. Along joists or studs, let PEX slide in the clips so it can lengthen and shorten as the water temperature changes, and follow your local plumbing code for support spacing.
Outline drawing
Schematic, not to scale. The clip is 12 mm wide along the pipe and about 17.3 mm high.
Parameters the generator will use
| Setting | Link parameter | Value |
|---|---|---|
| Model | model | pipe_clip |
| Pipe diameter | diameter | 15.9 |
| Fit clearance | fit_clearance | 0.3 |
| Clip wall thickness | wall | 2 |
| Clip width along the pipe | width | 12 |
| Opening angle, degrees | opening | 95 |
| Screw tab length | tab_length | 14 |
| Screw tab thickness | tab_thickness | 3 |
| Screw hole diameter | screw_diameter | 4.2 |
| Number of screw tabs | tabs | 1 |
All lengths are in millimetres. Outer size from these values: about 34.2 x 12 x 17.32 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 pipe and cable clip 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.