Engineering Tools · Stud Bolt Torque
Stud Bolt Torque Chart: M6–M36 Target Preload and Tightening Torque
Family index of the stud bolt torque charts: all 14 sizes from M6 to M36 with the coarse pitch, the thread stress area As, the class 10.9 target preload and the tightening torque at three nut factors (K 0.12 / 0.15 / 0.20). Each size opens its own page. Basis: K-factor method T = K·D·F with F = 70% of Rp0.2 × As — the same engine and the same parameters as the per-size pages.
Full PDF
Download the full PDF (M6–M36, all sizes)
Printable chart covering every size in this family — enter your email to get it.
Size Index ({sizes})
Click a size for its own page (the full six-class × K matrix, the fine-thread matrix, the stainless galling note and a pre-filled calculator). The three torque columns are all class 10.9; preload is independent of K — K only converts preload into torque.
| Size | Coarse pitch (mm) | Stress area As (mm²) | Preload, class 10.9 (kN) | Torque K 0.12 (N·m) | Torque K 0.15 (N·m) | Torque K 0.20 (N·m) |
|---|---|---|---|---|---|---|
| M6 | 1 | 20.1 | 13.2 | 10 | 12 | 16 |
| M8 | 1.25 | 36.6 | 24.1 | 23 | 29 | 39 |
| M10 | 1.5 | 58 | 38.2 | 46 | 57 | 76 |
| M12 | 1.75 | 84.3 | 55.5 | 80 | 100 | 133 |
| M14 | 2 | 115 | 75.7 | 127 | 159 | 212 |
| M16 | 2 | 157 | 103.3 | 198 | 248 | 331 |
| M18 | 2.5 | 192 | 126.3 | 273 | 341 | 455 |
| M20 | 2.5 | 245 | 161.2 | 387 | 484 | 645 |
| M22 | 2.5 | 303 | 199.4 | 526 | 658 | 877 |
| M24 | 3 | 353 | 232.3 | 669 | 836 | 1115 |
| M27 | 3 | 459 | 302 | 979 | 1223 | 1631 |
| M30 | 3.5 | 561 | 369.1 | 1329 | 1661 | 2215 |
| M33 | 3.5 | 694 | 456.7 | 1808 | 2260 | 3014 |
| M36 | 4 | 817 | 537.6 | 2322 | 2903 | 3871 |
Basis and Disclosed Assumptions
Calculation basis
- Torque follows the K-factor (nut factor) method T = K·D·F: D is the nominal diameter and F the target preload = 70% of Rp0.2 × thread stress area As, which the table gives size by size.
- Yield strengths are published values from ISO 898-1 (carbon/alloy steel) and ISO 3506-1 (stainless A2/A4). This table gives the mainstream class 10.9 only; the other five classes (4.8 / 8.8 / 12.9 / A2-70 / A4-80) are listed on each per-size page.
- The three K columns follow the standard stud-bolt torque table format (K = 0.12 / 0.15 / 0.20), the same three-column output as the online torque calculator's stud bolt mode.
Scope and limits
- This chart is a simplified K-factor estimate, not a full VDI 2230 analysis, which also accounts for joint resilience, embedment and assembly method.
- Friction and lubrication are the dominant variables — the spread between K 0.12 and K 0.20 can reach about 65% of the torque value.
- Only the mainstream class 10.9 is tabulated here; classes 4.8 / 8.8 / 12.9 / A2-70 / A4-80 and the fine-thread series are given on each per-size page.
- In execution, always follow the design specification or the manufacturer's torque table.
References
- ISO 898-1:2013 — Mechanical properties of fasteners made of carbon and alloy steel
- ISO 3506-1:2020 — Mechanical properties of corrosion-resistant stainless steel fasteners (A2/A4)
- GB/T 3098.1-2010 — Mechanical properties of bolts, screws and studs (CN national standard, official full text)
- GB/T 3098.6-2014 — Mechanical properties of stainless steel bolts, screws and studs (CN, official full text)
- ISO 16047:2005 — Fasteners: torque/clamp force testing (K-factor measurement method)
- Machinery's Handbook (30th ed.) — empirical K-factor ranges
- Machine Design — anti-seize compound friction test (K≈0.10)
Pre-fill this size and switch to fine thread?
The torque calculator covers stud bolts: pick the size and the K factor and get the target preload, the tightening torque and the fine-thread series — on the same engine and basis as this table.
Open the torque calculatorCite this chart
YAXIIO. Stud Bolt Torque Chart: M6–M36 Target Preload and Tightening Torque. https://www.yaxiio.com/en/tools/stud-bolt-torque-chart (accessed 2026-10-29).
Free to cite and embed — attribution required: “YAXIIO” + a link to this page.
FAQ
What is the target preload for an M12 stud bolt?
Taking M12, the family default: at 70% of Rp0.2 the class 10.9 target preload is 55.5 kN (As = 84.3 mm²). Preloads for the other classes at the same size — 4.8 / 8.8 / 12.9 and stainless A2-70 / A4-80 — are listed row by row on the M12 page. Preload is independent of the K value; K only converts preload into torque.
When should I use K 0.12, 0.15 or 0.20?
K is the nut factor combining thread and bearing-surface friction. Use 0.12 for well-lubricated assembly (MoS₂ paste or assembly oil on both threads and nut face), 0.15 as the typical default for normal lubrication, and 0.20 for unlubricated or plated (zinc/cadmium) surfaces. The spread is not small: at M12 this table gives 80 N·m at K 0.12 against 133 N·m at K 0.20. Field torque-tension verification is recommended for critical flange joints.
Can I use carbon-steel torque values for a stainless stud bolt?
No. The yield strengths differ (A2-70 = 450 MPa, A4-80 = 600 MPa), so the target preloads differ; and austenitic stainless thread pairs gall easily, so anti-seize must be applied and the installed torque verified on site. This table covers carbon and alloy steel class 10.9 only; the stainless classes are given on each per-size page.
Next: work out your order, or pick the size by standard
Related References
Stud Bolt Torque Calculator
Interactive: stud bolt mode pre-filled, K 0.12 / 0.15 / 0.20 columns, fine threads and a torque check.
Hex Bolt Torque Chart
Regular hex bolt tightening torques by friction state at the same size — compare with the stud bolt values.
Threaded Rod and Stud Bolt Weight Chart
kg/m and per-piece weights for the same size across the full length series, for quotation and logistics.
Double-End Stud Product Catalog
GB/T 901 series double-end studs — request a quote by size, material, property class and coating.
Disclaimer: this chart is an engineering estimate for selection and budgeting only; it does not constitute assembly instructions or acceptance criteria.