tq-threads

Why tq-threads

🧩 Manifold by construction

The thread surface is a helical height-field turned into one closed polyhedron — no boolean unions to go non-manifold. It renders cleanly and slices.

📐 Standards-based, clean-room

Built only from public standards (ISO 68-1/261/262/273/4032/4762/7089/10642, ASME B1.1). No third-party thread library was copied or consulted.

🖨️ Printable-first

Fit clearance, internal-oversize / external-undersize compensation, lead-in chamfers, rounded roots, and real $fn/$fa/$fs are all parameters.

🔩 Batteries included

101 presets (M1.6–M64 coarse + full ISO 261 fine + UNC/UNF #0–1″), plus bolts, nuts, washers, countersunk & wood screws, augers, Phillips drives, clearance/counterbore/countersink holes, standoffs, couplers, and child‑difference tq_tap/tq_drill wrappers. Square, rectangular, narrow-tooth, and groove profiles are generic printable forms; tune clearance for FDM fit.

⚖️ MIT licensed

Permissive and GPL-2.0-compatible, so it drops into a GPL-2.0-only project (e.g. TinkerQuarry) unchanged.

✅ Tested & CI

Compile-time preset assertions, split render cells, negative/assert tests, independent STL mesh checks, and GitHub Actions running the same proof on every push.

Architecture

Quick start

// install: git submodule / OPENSCADPATH / vendor the .scad
include <tq_threads.scad>;
$fn = 64;

// M8 × 1.25 threaded rod, 20 mm
tq_thread_preset("M8", 20);

// tapped M6 hole through a block
difference() {
    cube([20,20,12], center=true);
    tq_threaded_hole(d=6, pitch=1.0, depth=12);
}

// a cap screw + matching nut (same clearance ⇒ they fit)
tq_bolt(8, 1.25, 20, head="socket", shank=4);
tq_nut(8, 1.25);

Install

# 1) git submodule (versioned projects)
git submodule add https://github.com/scottconverse/tq-threads libs/tq-threads
# include <libs/tq-threads/tq_threads.scad>;

# 2) drop on the OpenSCAD library path
#   ~/Documents/OpenSCAD/libraries/  (Win/macOS)
#   ~/.local/share/OpenSCAD/libraries/  (Linux)

# 3) or download the release .zip and vendor the .scad

Only tq_threads.scad is needed at runtime. Coexists with BOSL2, NopSCADlib, etc. (everything is namespaced tq_*).

Migrating from `threads.scad`?

metric_thread(d,p,l) → tq_thread(d,p,l)
english_thread() → tq_thread_tpi()
ScrewHole() → difference(){…; tq_threaded_hole()}

Full table in the manual.

Presets

Metric coarse: M1.6 M2 M2.5 M3 M3.5 M4 M5 M6 M7 M8 M10 M12 M14 M16 M18 M20 M22 M24 M27 M30 M33 M36 M39 M42 M45 M48 M52 M56 M60 M64
Metric fine: M8x1 M10x1.25 M10x1 M12x1.5 M12x1.25 M16x1.5 M20x1.5 M24x2 · Unified: 1/4-20 1/4-28 3/8-16 3/8-24 1/2-13 1/2-20