A family of screw-top storage jars that print with no supports: three diameters, two heights each, and a lid for every diameter in three thread fits so you can match your printer. A small thread test neck lets you check the fit in about 20 minutes before printing the big jars.

What's included (16 models, STL + 3MF, in print orientation)

• 6 jars: Ø40 × 50 (38 ml), Ø40 × 80 (68 ml), Ø60 × 60 (123 ml), Ø60 × 100 (221 ml), Ø80 × 70 (277 ml), Ø80 × 120 (504 ml)
• Openings: Ø26 mm on the Ø40 jars, Ø46 mm on the Ø60 jars, Ø66 mm on the Ø80 jars
• 9 lids: tight, standard and loose for each diameter (radial clearance 0.4 / 0.5 / 0.6 mm, marked by 1 / 2 / 3 grooves inside the lid). One lid fits both heights of its diameter.
• Thread test neck (Ø40, 17 mm tall) for the three Ø40 lids
• The .blend file and the parametric Python generator (change sizes, clearances or the thread and rebuild)

Why these jars

• Two-start rounded thread (5.2 mm pitch, 10.4 mm lead): closes in about 1.1 turns and starts easily
• Every surface is 45° or less, threads included, so nothing needs supports; lids print top-down
• Flush outer wall: the lid seats on the jar shoulder; fluted grip on every lid
• 2.0 mm walls and floor, chamfered bottom edges against elephant's foot

Print settings

• PLA or PETG, 0.4 mm nozzle, 0.2 mm layers, 3 perimeters, 15 % infill, no supports, no brim
• Jars upright, lids upside down, exactly as supplied

Please note

FDM prints are not airtight or watertight and are not certified food-safe. Use them for dry goods, hardware, craft supplies and small parts.

Thread and fit

Two-start rounded thread: pitch 5.2 mm, lead 10.4 mm, depth 1.6 mm, max flank slope 44 deg
Closes in about 1.1 turns; the lid seats on the jar shoulder (flush outer wall), 0.4 mm above the rim
Thread run-outs cut back at 42 deg on jar and lid
Walls 2.0 mm, floor 2.0 mm, lid top 2.4 mm, lid wall >= 1.2 mm at the flute valleys (1.24 / 1.28 / 1.30 mm measured for Ø40 / 60 / 80)
Radial clearance: tight 0.4 / standard 0.5 / loose 0.6 mm (1 / 2 / 3 grooves inside the lid)
Measured smallest thread gap when seated: 0.29 / 0.36 / 0.43 mm

Blender check (Blender 5.2.1, every file)

* Solid-volume mass in PLA (1.24 g/cm³); with 2.0 mm walls a 3-perimeter print is close to this.

• Every part: 1 closed shell, 0 open edges, 0 non-manifold edges, consistent outward normals, 0 degenerate faces, no face steeper than 45°.
• 18 jar + lid pairs and the test neck with all three d40 lids: 0 intersecting triangles when seated.
• Unscrew simulation (15° steps over 1.1 turns, rising 10.4 mm per turn): 0 collisions for every pair. Pulling a lid straight up without turning collides, so the threads really engage.
• Every STL and 3MF re-imported and matched its source (triangle count and volume).
• Not yet physically test-printed; print the test neck and the three d40 lids first to choose your fit.