Garden hose thread (GHT 3/4-11.5 NH) dimensions, hose sizes, BSP G3/4 and Gardena for comparison — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/garden-hose-thread/  (CC BY 4.0)
Basis: ASME B1.20.7 table (Machinery's Handbook), Dixon fitting guide; ISO 228 for BSP; Gardena product pages
Catalog version: 2026-10-20

Sizes: see table below
- US garden hose: 3/4-11.5 NH (GHT): 11.5 threads per inch (2.209 mm pitch). Male nipple major Ø26.56–26.99, pitch Ø25.34–25.55, minor ≤24.12 mm. Female coupling major ≥27.24, minor 24.37–24.80.
- It is NOT pipe thread: 3/4 in NPT (14 TPI, tapered) and BSP G3/4 (14 TPI, Ø26.44 major) look close and cross-thread; GHT seals on the washer, not the threads.
- Hose sizes are inside diameters: 1/2, 5/8 (a Flexzilla 5/8 is 15.7 mm ID), 3/4 in; ODs are not published.
- Europe: taps are G3/4 (Gardena '26.5 mm'), G5/8 ('23 mm') and G1/2 ('21 mm'); Gardena click-coupling geometry is not published.
- Printed GHT parts (free STL): male thread drawn slightly under (major 26.6, minor 24.1) so it threads into real couplings; use the rubber washer to seal, PETG or ASA outdoors.

thread  TPI  pitch_mm  major_mm  minor_mm
GHT 3/4-11.5 NH male  11.5  2.209  26.56–26.99  ≤24.12
GHT female coupling  11.5  2.209  ≥27.24  24.37–24.80
BSP G3/4 (ISO 228)  14  1.814  26.441  24.117

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Machinery's Handbook (ASME B1.20.7 table): Hose coupling screw threads — web — Publisher's page; dimensions are facts — https://online.flippingbook.com/view/954046886/744-745/
- Dixon Valve: Thread identification guide — web — Publisher's page; dimensions are facts — https://canada.dixonvalve.com/en/media/1409739
- PRESSOL: Whitworth pipe thread ISO 228 (G3/4) — web — Publisher's page; dimensions are facts — https://www.pressol.com/informationen/spezifikationsdokumente-gewinde/zylindrisches-whitworth-rohrgewinde-nach-diniso-228/?lang=en
- Gardena: Tap connector thread sizes — web — Publisher's page; dimensions are facts — https://www.gardena.com/za/products/watering/hose-fittings/tap-connector/970565601.html
- Alaska Rubber Group (spec): Flexzilla 5/8 in hose — web — Publisher's page; dimensions are facts — https://www.alaskarubbergroup.com/flexzilla-hfzg550yw-green-polymer-garden-hose-5/8-in-50-ft-l-150-psi

Free files (CC BY 4.0, Xem Studio; STEP + STL, 3 parts): https://xemstudio.com/files/hardware/garden-hose-thread/index.json
API: https://xemstudio.com/api/geometry?object=garden-hose-thread