--- title: "GB T 5973 Turnbuckle Specification" description: "GB T 5973 Turnbuckle: full dimensional table with tolerances. DIN, ISO and ASME equivalents listed side by side. Head, thread and length ranges in one chart." url: https://engineeringhardware.com/guide/standard/gb-t-5973-cad-svg-156-turnbuckle/ source: Engineering Hardware & Fasteners --- # GB T 5973 Turnbuckle Specification Rigging Hardware · ISO / DIN Dimensional table, tolerance classes and the DIN / ISO / ASME parts that supersede or match this standard. GB T 5973 specifies the dimensions and tolerances for turnbuckle. The full dimensional table is reproduced below, followed by the DIN, ISO and ASME parts that match or supersede it. - **Standard:** GB T 5973 - **Product:** Turnbuckle — ISO / DIN (Series 156) - **Governing standards:** ISO / DIN Equivalence between national standards is dimensional, not always metallurgical. Check the property class separately when substituting. ![GB T 5973 Turnbuckle Specification reference image](https://engineeringhardware.com/wp-content/uploads/2026/06/Turnbuckle-—-ISO-DIN-Series-156-—-ISO-DIN.webp) For turnbuckle, GB T 5973 is the governing document for the dimensions listed below. Mechanical and performance requirements for this part family are set by its own standards, not by the bolt and screw property-class documents. ## GB T 5973 — Scope The table below lists the dimensions catalogued for turnbuckle — iso / din (series 156) under GB T 5973. The scope of GB T 5973 itself is not summarised here — where a figure matters, confirm it against the published document. ## Tolerance & Product Grades Product grade is a concept from dimensional fastener standards and does not apply to GB T 5973. Tolerances for this part are the limits shown against each dimension in the table. ## Dimensions Specified by GB T 5973 | 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 | ## Equivalent Standards Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Turnbuckle — ISO / DIN (Series 156) page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry. ## When to Specify GB T 5973 Choose GB T 5973 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for turnbuckle — iso / din (series 156). Custom manufacturing · Made to drawing ## Need a rigging hardware to this standard in a non-standard size? Parts built to GB T 5973 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. 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 M6 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):** 105 - **Take-up length (mm):** 75 - **Working load limit (kg):** 80 - **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 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 ### Can I substitute GB T 5973 for the corresponding DIN standard on a drawing? On modern drawings the ISO standard is the master reference; the older DIN equivalent is a cross-reference. For most dimensional purposes the parts are interchangeable, but check tolerance grades and the head height — these are the most common points of divergence. ### Which edition of GB T 5973 does this table follow? The table reproduces the dimensions we supply turnbuckle — iso / din (series 156) to. We do not publish an edition year against it, so where the edition is contractually significant, cite the edition you require on the enquiry and we will confirm it against the table before quoting. ### 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