--- title: "M20 Turnbuckle Dimensions" description: "M20 Turnbuckle: coarse thread pitch 2.5 mm. Full size chart to ISO / DIN with tolerances." url: https://engineeringhardware.com/guide/size/m20-cad-svg-156-turnbuckle/ source: Engineering Hardware & Fasteners --- # M20 Turnbuckle Dimensions Rigging Hardware · ISO / DIN Controlling dimensions to ISO / DIN, with working load limit. M20 Turnbuckle dimensions to ISO / DIN: coarse thread pitch 2.5 mm. - **Coarse thread pitch:** 2.5 mm Figures are nominal values from the governing standard. Confirm against the tolerance class for your application before machining or ordering. ![M20 Turnbuckle Dimensions reference image](https://engineeringhardware.com/wp-content/uploads/2026/06/Turnbuckle-—-ISO-DIN-Series-156-—-ISO-DIN.webp) M20 Turnbuckle are manufactured to ISO / DIN. This page lists the controlling dimensions for the M20 size together with the rated working load limit and the notes for safe installation. Values are taken from the governing standard rather than from a general machine-thread table, because this type is not selected on one. ## M20 Dimensional Row (ISO / DIN) | Thread size | Total length closed (mm) | Take-up length (mm) | Working load limit (kg) | Material | Reference standard | | --- | --- | --- | --- | --- | --- | | M20 | 290 | 215 | 1200 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 | Custom manufacturing · Made to drawing ## Need turnbuckle in a size this table does not list? This page covers M20 turnbuckle. Dimensions, material, finish and form are specified from the drawing — a rigging hardware outside the standard range is a variation on existing tooling rather than a new design. Made by hot forging. Minimum order from 2,000 pieces; samples within 7 days of drawing approval. [Custom rigging hardware manufacturing](https://engineeringhardware.com/custom/rigging/)[Send a drawing](https://engineeringhardware.com/custom/rigging/#rfq) ## Technical Drawing Dimensioned line drawing of M20 Turnbuckle — ISO / DIN (Series 156). Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected. - **Total length closed (mm):** 290 - **Take-up length (mm):** 215 - **Working load limit (kg):** 1200 - **Material:** Drop-forged steel, hot-dip galvanized ## Dimensions & Specifications (ISO / DIN) | Thread size | Total length closed (mm) | Take-up length (mm) | Working load limit (kg) | Material | Reference standard | | --- | --- | --- | --- | --- | --- | | M6 | 105 | 75 | 80 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 | | M8 | 125 | 90 | 140 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 | | M10 | 150 | 110 | 230 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 | | M12 | 180 | 135 | 340 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 | | M16 | 230 | 170 | 700 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 | | M20 | 290 | 215 | 1200 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 | | M24 | 355 | 260 | 1800 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 | | M30 | 420 | 320 | 3200 | Drop-forged steel, hot-dip galvanized | DIN 1480 / GB/T 5973 | ## Materials & Grades Select a material class to see the grades we supply it in. Each designation is listed with its ISO/EN, AISI/SAE, JIS and GB equivalents. Stainless Steel38 Carbon Steel66 Alloy Steel41 Bearing Steel5 Spring Steel25 Aluminum and Aluminum Alloys21 Brass17 Bronze11 Copper8 Titanium and Titanium Alloys18 Nickel and Nickel Alloys22 Iron-Nickel and High-Temperature Alloys10 Tool Steel and Specialty Hardened Steel9 Structural and Construction Steel9 ### Stainless Steel #### Austenitic Stainless Steel - A1 AISI 303 · SAE 303 · SUS303 · EN 1.4305 · X8CrNiS18-9 - A2 AISI 304 · SAE 304 · SUS304 · EN 1.4301 · X5CrNi18-10 · 06Cr19Ni10 - 304L AISI 304L · SUS304L · EN 1.4307 · X2CrNi18-9 · 022Cr19Ni10 - 302 AISI 302 · SUS302 · EN 1.4310 - 305 AISI 305 · SUS305 · EN 1.4303 - A4 AISI 316 · SAE 316 · SUS316 · EN 1.4401 · X5CrNiMo17-12-2 · 06Cr17Ni12Mo2 - 316L AISI 316L · SUS316L · EN 1.4404 · X2CrNiMo17-12-2 · 022Cr17Ni12Mo2 - 321 AISI 321 · SUS321 · EN 1.4541 · X6CrNiTi18-10 - 310 / 310S AISI 310 · AISI 310S · SUS310S · EN 1.4845 - 302HQ AISI 302HQ - A3 - A5 - 347 AISI 347 · SUS347 · EN 1.4550 · X6CrNiNb18-10 - 309 / 309S AISI 309 · AISI 309S · SUS309S #### Martensitic Stainless Steel - AISI 410 SUS410 · EN 1.4006 · X12Cr13 · 12Cr13 - AISI 420 SUS420J1 · SUS420J2 · EN 1.4021 · EN 1.4028 · 20Cr13 · 30Cr13 - AISI 431 SUS431 · EN 1.4057 · X17CrNi16-2 - C1 - C3 - C4 - AISI 440A - AISI 440B - AISI 440C SUS440C · EN 1.4125 #### Ferritic Stainless Steel - AISI 430 SUS430 · EN 1.4016 · X6Cr17 · 10Cr17 - F1 - AISI 434 - AISI 444 #### Precipitation-Hardening Stainless Steel - 17-4 PH AISI 630 · UNS S17400 · SUS630 · EN 1.4542 · X5CrNiCuNb16-4 - 15-5 PH UNS S15500 - 17-7 PH UNS S17700 #### Duplex and Super Duplex Stainless Steel - Duplex 2205 UNS S31803 · UNS S32205 · EN 1.4462 - Super Duplex 2507 UNS S32750 · EN 1.4410 - D2 - D4 - D6 - D8 - Lean Duplex 2101 UNS S32101 - Super Duplex S32760 UNS S32760 · EN 1.4501 ### Carbon Steel #### Low-Carbon Steel - SAE 1006 - SAE 1008 - SAE 1010 - SAE 1018 - SAE 1020 - Q195 - Q235 - SAE 1012 - SAE 1015 - Q215 - ML08 - ML08Al - ML10 - ML15 - ML20 - SWRCH6A - SWRCH8A - SWRCH10A - SWRCH12A - SWRCH15A - SWRCH18A #### Medium-Carbon Steel - SAE 1035 - SAE 1045 - S45C - C45 - SAE 1030 - SAE 1040 - SAE 1050 - 30 - 35 - 40 - 45 - 50 - S35C - S40C - S50C - C35 - C40 #### High-Carbon Steel - SAE 1060 - SAE 1070 - 65Mn - SAE 1065 - SAE 1075 - SAE 1080 - SAE 1085 - SAE 1090 - SAE 1095 - 60 - 65 - 70 - 75 - 80 - 85 #### Cold-Heading Steel - SWRCH22A - 10B21 - SWRCH22K - SWRCH25K - SWRCH30K - SWRCH35K - SWRCH40K - ML20Mn - ML25 - ML30 - ML35 - ML40 - 15B25 ### Alloy Steel #### Chromium Steel - 40Cr - 45Cr - AISI 5140 - SAE 5140 - AISI 5120 - SAE 5120 - SCr420 - SCr440 #### Chromium-Molybdenum Steel - 35CrMo - 42CrMo - AISI 4140 - SCM435 - SCM440 - 42CrMo4 - 30CrMo - AISI 4130 - SAE 4130 - SAE 4140 - AISI 4142 - AISI 4145 - SCM415 - SCM420 - SCM445 - EN 1.7220 - EN 1.7225 - 25CrMo4 - 34CrMo4 #### Nickel-Chromium-Molybdenum Steel - AISI 4340 - SAE 4340 - 40CrNiMo - SNCM439 - EN 1.6511 - 36CrNiMo4 #### Boron Alloy Steel - 10B22 - 10B21 - 15B21 - 15B25 - 20MnTiB - 20Mn2B - 35VB - 40MnB ### Bearing Steel #### Bearing Steel - GCr15 - AISI 52100 SAE 52100 · UNS G52986 - SUJ2 - 100Cr6 EN 1.3505 - GCr15SiMn ### Spring Steel #### Carbon Spring Steel - SAE 1065 - SAE 1070 - SAE 1075 - SAE 1080 - SAE 1095 - 65 - 70 - 75 - 80 - 65Mn #### Silicon-Manganese Spring Steel - 60Si2Mn - 60Si2MnA - SUP6 - SUP7 #### Chromium-Vanadium Spring Steel - 50CrVA - SAE 6150 - AISI 6150 - SUP10 #### Stainless Spring Steel - AISI 301 - SUS301 - EN 1.4310 - AISI 302 - AISI 304 - AISI 316 - 17-7 PH ### Aluminum and Aluminum Alloys #### Commercially Pure Aluminum - 1050 - 1060 - 1070 - 1100 #### 2xxx Series Aluminum - 2024 - 2011 - 2014 - 2017 #### 5xxx Series Aluminum - 5052 - 5083 - 5754 #### 6xxx Series Aluminum - 6061 - 6061-T6 - 6063 - 6082 - 6082-T6 #### 7xxx Series Aluminum - 7075 - 7075-T6 - 7005 - 7050 - 7075-T73 ### Brass #### Free-Cutting Brass - C36000 - H62 - HPb59-1 - C3601 - C3602 - C3604 - CuZn36Pb3 - CuZn39Pb3 - EN CW614N - EN CW617N - H65 #### Lead-Free Brass - C69300 - C27450 - CW510L - CW511L #### Naval Brass - C46400 - CuZn39Sn1 ### Bronze #### Silicon Bronze - C65500 - C65100 - C65600 #### Phosphor Bronze - C51000 - C52100 - CuSn6 - CuSn8 #### Aluminum Bronze - C95400 - C95500 - C63000 - CuAl10Ni5Fe4 ### Copper #### Copper - C11000 - T2 - C10100 - C10200 - C12200 - T1 - TU1 - TU2 ### Titanium and Titanium Alloys #### Commercially Pure Titanium - Grade 2 - Grade 1 - Grade 3 - Grade 4 - TA1 - TA2 - TA3 #### Alpha-Beta Titanium Alloys - Grade 5 - Ti-6Al-4V - TC4 - UNS R56400 #### Low-Interstitial Grade - Grade 23 - Ti-6Al-4V ELI - UNS R56407 #### Other Titanium Fastener Alloys - Ti-6Al-6V-2Sn - Ti-6Al-2Sn-4Zr-2Mo - Beta-C titanium - Ti-10V-2Fe-3Al ### Nickel and Nickel Alloys #### Commercially Pure Nickel - Nickel 200 - UNS N02200 - Nickel 201 - UNS N02201 #### Inconel Alloys - Inconel 625 UNS N06625 - Inconel 718 UNS N07718 - Inconel 600 UNS N06600 - Inconel 601 UNS N06601 - Inconel 686 UNS N06686 - Inconel X-750 UNS N07750 #### Monel Alloys - Monel 400 UNS N04400 - Monel K-500 UNS N05500 #### Hastelloy Alloys - Hastelloy C-276 UNS N10276 - Hastelloy C-22 UNS N06022 - Hastelloy B-2 UNS N10665 - Hastelloy B-3 UNS N10675 - Hastelloy X UNS N06002 #### Other Nickel Alloys - Alloy 20 UNS N08020 - Alloy 625 - Alloy 718 - Alloy 825 UNS N08825 - Alloy 925 UNS N09925 ### Iron-Nickel and High-Temperature Alloys #### A286 - A-286 - UNS S66286 - EN 1.4980 #### Invar - Invar 36 - Alloy 36 - UNS K93600 - FeNi36 #### Alloy 42 - Alloy 42 - UNS K94100 - FeNi42 ### Tool Steel and Specialty Hardened Steel #### Tool Steel and Specialty Hardened Steel - AISI D2 - AISI H13 - SKD11 - Cr12MoV - AISI O1 - AISI A2 - AISI S7 - SKD61 - 9CrSi ### Structural and Construction Steel #### Structural and Construction Steel - ASTM A36 - Q235B - Q355B - S355JR - Q235C - Q355C - S235JR - S275JR - S355J2 ## Applications & Industries for M20 Turnbuckle The sectors that buy Turnbuckle, and the duty each one buys them for. Stocked from M6 to M30. ### Industries that specify Turnbuckle - **Marine & outdoor:** Standing rigging, guys and tie-downs. - **Lifting & rigging:** Rope assemblies, terminations and tensioners. ### Typical applications - securing loads within a rated working load limit - terminating and tensioning wire rope ### Service conditions to specify against - **Exterior structural:** Hot-dip galvanised options for external steelwork; allow for the thicker coating in the mating thread. [Full application guide: where Turnbuckle are used, how to specify them, and the cases they are wrong for](https://engineeringhardware.com/applications/cad-svg-156-turnbuckle/) Inside the plant ## Manufactured in our own plant This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided. 1. ![Wire rod feeding into a cold heading machine](https://engineeringhardware.com/wp-content/uploads/2026/08/09-wire-rod-feed-cold-heading-machine.webp) 01 **Cold heading** Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail. Head dimensions and under-head radius checked at set-up and per shift. 2. ![Thread rolling machine producing bolt threads](https://engineeringhardware.com/wp-content/uploads/2026/08/03-thread-rolling-machine-bolt-production.webp) 02 **Thread rolling** Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch. Go / no-go ring gauges to ISO 965 tolerance class 6g. 3. ![Baskets of bolts staged for heat treatment](https://engineeringhardware.com/wp-content/uploads/2026/08/05-heat-treatment-baskets-black-bolts.webp) 03 **Heat treatment** Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it. Core hardness and tensile tested per lot to ISO 898-1. 4. ![Zinc plated bolts in a treatment basket](https://engineeringhardware.com/wp-content/uploads/2026/08/23-zinc-plated-bolts-treatment-basket.webp) 04 **Surface treatment** Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list. Coating thickness and neutral salt spray hours to ISO 9227. ## Frequently Asked Questions ### What clearance and tapping drill suit M20? Use a 22 mm clearance hole (ISO 273 medium) for through-fixing, or a 17.5 mm tapping drill for a coarse M20 thread. ### Should M20 Turnbuckle — ISO / DIN (Series 156) be tightened by torque or by angle? For critical structural joints at M20, angle-controlled or stretch-controlled tightening is more repeatable than pure torque — the friction scatter at large diameters can dominate the torque signal. ### What grip range is typical for M20 structural bolts? Grip ranges are highly application-dependent at M20. As a guide, choose a length that gives at least 1× the thread diameter engagement in the nut plus 2–3 thread pitches projecting. ### What is the coarse-thread pitch of M20 for Turnbuckle — ISO / DIN (Series 156)? For M20 the standard coarse pitch is 2.5 mm — this is the value used for Turnbuckle — ISO / DIN (Series 156). ### How do I request a quotation? Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day. ## Related Pages [View the full Turnbuckle — ISO / DIN (Series 156) page](https://engineeringhardware.com/fastener/cad-svg-156-turnbuckle/) ### More Turnbuckle — ISO / DIN (Series 156) Guides