Coupling nuts / long hex nuts: DIN 6334 M8–M36 (height 3 d) and inch rod coupling nuts 1/4 to 1 in — across flats, length + M8–M36 envelope models — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/coupling-nuts-din-6334-and-inch/ (sheet CC BY 4.0) Basis: dinmark's DIN 6334 table (checked at M12 against a Wuerth listing); two inch coupling-nut tables (American Fastener and Alma Bolt) that disagree and are shown side by side; eight DIN 6334 envelope models as files Catalog version: 2026-10-20 Overall (mm): length 15.0, width 13.0, height 24.0 - DIN 6334 is the hexagon nut with a height of 3 × d (a long nut, used to join two threaded rods or studs, or as a spacer / tensioner). dinmark's table, M8 to M36, gives pitch (coarse), width across flats s and height m (m = 3 d: 24 for M8, 30 for M10, 36 for M12, 48 for M16, 60 for M20, 72 for M24, 90 for M30, 108 for M36). The page prints no width across corners. A Wuerth listing for the M12 nut (WN 6334, steel class 8) prints height 36 mm, width across corners 21.1 mm and a wrench size WS19; that is the only second source read, and it matches dinmark's s 19 and m 36. M6 and the 1.5 d version are not on this page. - Inch coupling nuts: no standard is cited by either source. American Fastener's sheet (1/4 to 1 in) and Alma Bolt's rod coupling nut table (1/4-20 to 1-8) agree on the hex size for 1/4 (3/8 across flats), 5/16 (1/2) and, for the shorter 3/8 nut, but disagree elsewhere. Length of the 1/4 nut: 3/4 in (American Fastener) against 7/8 in (Alma). 3/8: American Fastener 9/16 across flats × 1-1/8 long; Alma lists 1/2 × 1-1/8 and 9/16 × 1-3/4. 1/2: 3/4 × 1-1/2 against 11/16 × 1-3/4. 5/8: 15/16 × 1-7/8 against 13/16 × 2-1/8. 3/4: 1-1/8 × 2-1/4 against 1 × 2-1/4. 1: 1-1/2 × 3 against 1-3/8 × 2-3/4. Alma also lists a second 5/16 nut (1-1/8 long, against 7/8 and American Fastener's 15/16). Both sets are shown; no inch file is drawn because the dimensions are not settled. Alma's source text lists the last size as '1/8', read as 1-8. - Files are Xem-drawn envelopes of DIN 6334: a hexagon at the published width across flats and height 3 d with a plain bore at the thread major diameter (the real thread is smaller); no chamfers on the corners or faces. Hexagon corners are across-flats / cos 30°. - McMaster-Carr sells coupling nuts (inch and reducing) with per-part STEP; its Grade 2 steel coupling-nut page is linked, not copied. Standard hex nuts: hex-nuts-metric, hex-nuts-inch. standard / source size pitch width across flats width across corners length / height note DIN 6334 (dinmark) M8 1.25 mm 13 mm — 24 mm (= 3 d) — DIN 6334 (dinmark) M10 1.5 mm 17 mm — 30 mm (= 3 d) — DIN 6334 (dinmark) M12 1.75 mm 19 mm — 36 mm (= 3 d) — DIN 6334 (dinmark) M16 2 mm 24 mm — 48 mm (= 3 d) — DIN 6334 (dinmark) M20 2.5 mm 30 mm — 60 mm (= 3 d) — DIN 6334 (dinmark) M24 3 mm 36 mm — 72 mm (= 3 d) — DIN 6334 (dinmark) M30 3.5 mm 46 mm — 90 mm (= 3 d) — DIN 6334 (dinmark) M36 4 mm 55 mm — 108 mm (= 3 d) — inch, American Fastener (no standard cited) 1/4 — 3/8 in (0.375 / 0.365) 0.433 / 0.416 in 3/4 in (0.76 / 0.74) — inch, American Fastener (no standard cited) 5/16 — 1/2 in (0.500 / 0.489) 0.577 / 0.557 in 15/16 in (0.95 / 0.93) — inch, American Fastener (no standard cited) 3/8 — 9/16 in (0.562 / 0.551) 0.650 / 0.628 in 1-1/8 in (1.13 / 1.11) — inch, American Fastener (no standard cited) 1/2 — 3/4 in (0.750 / 0.736) 0.866 / 0.839 in 1-1/2 in (1.51 / 1.49) — inch, American Fastener (no standard cited) 5/8 — 15/16 in (0.938 / 0.922) 1.083 / 1.051 in 1-7/8 in (1.89 / 1.86) — inch, American Fastener (no standard cited) 3/4 — 1-1/8 in (1.125 / 1.088) 1.299 / 1.240 in 2-1/4 in (2.27 / 2.22) — inch, American Fastener (no standard cited) 1 — 1-1/2 in (1.500 / 1.450) 1.732 / 1.653 in 3 in (3.03 / 2.97) — inch, Alma Bolt (no standard cited) 1/4-20 coarse as named 3/8 in (0.375 / 0.365) 0.433 / 0.416 in 7/8 in (0.89 / 0.86) differs from American Fastener at several sizes inch, Alma Bolt (no standard cited) 5/16-18 coarse as named 1/2 in (0.500 / 0.489) 0.577 / 0.557 in 7/8 in (0.89 / 0.86) differs from American Fastener at several sizes inch, Alma Bolt (no standard cited) 5/16-18 coarse as named 1/2 in (0.500 / 0.489) 0.577 / 0.557 in 1-1/8 in (1.13 / 1.11) differs from American Fastener at several sizes inch, Alma Bolt (no standard cited) 3/8-16 coarse as named 1/2 in (0.500 / 0.489) 0.577 / 0.557 in 1-1/8 in (1.13 / 1.11) differs from American Fastener at several sizes inch, Alma Bolt (no standard cited) 3/8-16 coarse as named 9/16 in (0.562 / 0.551) 0.650 / 0.628 in 1-3/4 in (1.76 / 1.73) differs from American Fastener at several sizes inch, Alma Bolt (no standard cited) 1/2-13 coarse as named 11/16 in (0.688 / 0.663) 0.794 / 0.756 in 1-3/4 in (1.76 / 1.73) differs from American Fastener at several sizes inch, Alma Bolt (no standard cited) 5/8-11 coarse as named 13/16 in (0.813 / 0.782) 0.939 / 0.891 in 2-1/8 in (2.14 / 2.10) differs from American Fastener at several sizes inch, Alma Bolt (no standard cited) 3/4-10 coarse as named 1 in (1.000 / 0.963) 1.155 / 1.097 in 2-1/4 in (2.27 / 2.22) differs from American Fastener at several sizes inch, Alma Bolt (no standard cited) 1-8 coarse as named 1-3/8 in (1.375 / 1.325) 1.588 / 1.511 in 2-3/4 in (2.78 / 2.72) differs from American Fastener at several sizes Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - dinmark: DIN 6334 high hexagon nut: thread, pitch, s (across flats), m (height) M8 to M36 — web — Distributor page; numbers only — https://dinmark.com.ua/en/shop/hayky/hayky-shestyhranni/din-6334-hayka-vysoka-shestyhranna/din-6334-10-hayka-vysoka-shestyhranna - Wuerth: Hexagonal nut 3 x d high WN 6334, M12: height 36, width across corners 21.1, wrench size WS19 — web — Maker shop page; numbers only — https://eshop.wuerth-ag.ch/Hexagonal-nut-3xd-high-WN-6334-steel-8-plain-NUT-HEX-WN6334-8-WS19-M12/5140112.sku/en/US/CHF - American Fastener: Hex coupling nuts: nominal size, width across flats and corners, length (basic / max / min), 1/4 to 1 (no standard cited) — web — Maker data sheet; numbers only — https://www.americanfastener.com/wp-content/uploads/2020/06/NUTS-HEX-COUPLING-AMERICAN-FASTENER.pdf - Alma Bolt: Rod coupling nuts (hex coupling nuts): size, major diameter, across flats / corners, length (basic / max / min), 1/4-20 to 1-8 (no standard cited) — web — Distributor catalog; numbers only — https://almabolt.com/pages/catalog/nuts/coupling.htm - McMaster-Carr: Grade 2 steel coupling nuts (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/products/grade-2-steel-coupling-nuts/ Free files (CC BY 4.0, Xem Studio; STEP + STL, 8 parts): https://xemstudio.com/files/hardware/coupling-nuts-din-6334-and-inch/index.json API: https://xemstudio.com/api/geometry?object=coupling-nuts-din-6334-and-inch