---
title: "M16 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) Dimensions"
description: "M16 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) dimensions to ASTM F3125/F3125M Grade F1852 and F2280. Tightening torque 209 Nm at class 8.8."
url: https://engineeringhardware.com/guide/size/m16-tension-control-structural-bolt-assemblies/
source: Engineering Hardware & Fasteners
---

# M16 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) Dimensions

Bolts · ASTM F3125/F3125M Grade F1852 and F2280

Controlling dimensions to ASTM F3125/F3125M Grade F1852 and F2280, with clearance hole and tapping drill, spanner or drive size and tightening torque.

M16 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) are dimensioned by ASTM F3125/F3125M Grade F1852 and F2280. The controlling dimensions, tolerance classes and assembly data are tabulated below.

- **Tightening torque (class 8.8):** 209 Nm

Figures are nominal values from the governing standard. Confirm against the tolerance class for your application before machining or ordering.

![M16 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) Dimensions reference image](https://engineeringhardware.com/wp-content/uploads/2026/09/Tension-Control-Structural-Bolt-Assembly-TC-Twist-Off.webp)

Dimensional and assembly data for M16 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) to ASTM F3125/F3125M Grade F1852 and F2280. Includes head size and width across flats, clearance-hole and tapping-drill diameters, tightening torque per property class, and the sizes to step up or down to when the joint requires it.

## M16 Dimensional Row (ASTM F3125/F3125M Grade F1852 and F2280)

| Size | Thread series | Assembly | Minimum installation tension F1852 (lbf) | Minimum installation tension F2280 (lbf) | Finish | Reference standard |
| --- | --- | --- | --- | --- | --- | --- |
| M16 | Metric option | bolt + twist-off nut + washer |  |  | Plain, heat-treated alloy steel | ASTM F3125/F3125M Grade F1852 and F2280 |

## Spanner & Drive for M16 Tension-Control Structural Bolt Assemblies (TC / Twist-Off)

Drive geometry for M16 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) is given by the row above; match the tool to the listed values.

## Hole Sizes for M16

| Coarse-thread pitch (ISO 724) | 2 mm |
| --- | --- |
| Through-hole / clearance (ISO 273 medium) | 17.5 mm |
| Tapping drill, coarse thread | 14 mm |

## Tightening Torque for M16

| Class 8.8 (dry, ~µ 0.125) | ≈ 209 Nm |
| --- | --- |
| Class 10.9 (dry, ~µ 0.125) | ≈ 306 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 358 Nm |

Indicative dry-joint values. Lubrication can lower the required torque by 15–25%. Always confirm against the joint design, especially when going up a strength class.

## Proof Load & Strength for M16

| Tensile stress area As (ISO 724) | 157 mm² |
| --- | --- |
| Proof load, class 8.8 | 91 kN |
| Proof load, class 10.9 | 130 kN |
| Proof load, class 12.9 | 152 kN |
| Min. ultimate tensile load, class 8.8 | 125 kN |

Proof load = tensile stress area × the proof stress Sp of the class, per ISO 898-1 — Sp is a lower figure than the yield stress Rp0.2 and the two are not interchangeable. The stress area is computed from this size's own diameter and pitch, so a fine-pitch designation gives the fine-pitch figure. Design the joint so the working preload stays below the proof load of the class selected.

## Mating Parts for M16

For M16, pair with a M16 hex nut (ISO 4032 / DIN 934) and, where used, a M16 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.

## When to Step Up or Down from M16

When the joint preload approaches the proof load of M16 class 8.8, step up to M20 class 8.8 (or move to M16 class 10.9). When the joint is over-specified, M12 often saves weight and cost without losing the safety margin.

Custom manufacturing · Made to drawing

## Need tension-control structural bolt assemblies (tc / twist-off) in a size this table does not list?

This page covers M16 tension-control structural bolt assemblies (tc / twist-off). Material and finish are usually what drives a special — a grade the standard part is not stocked in, or a coating chosen against a salt-spray figure instead of a default. Made by cold heading or hot forging.

Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

[Custom bolt manufacturing](https://engineeringhardware.com/custom/bolts/)[Send a drawing](https://engineeringhardware.com/custom/bolts/#rfq)

## Technical Drawing

Dimensioned line drawing of M16 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) to ASTM F3125/F3125M Grade F1852 and F2280. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.

- **Thread series:** Metric option
- **Assembly:** bolt + twist-off nut + washer
- **Finish:** Plain, heat-treated alloy steel

## Dimensions & Specifications (ASTM F3125/F3125M Grade F1852 and F2280)

| Size | Thread series | Assembly | Minimum installation tension F1852 (lbf) | Minimum installation tension F2280 (lbf) | Finish | Reference standard |
| --- | --- | --- | --- | --- | --- | --- |
| 1/2-13 | UNC | bolt + twist-off nut + washer | 12,550 | 15,650 | Plain, heat-treated alloy steel | ASTM F3125/F3125M Grade F1852 and F2280 |
| 5/8-11 | UNC | bolt + twist-off nut + washer | 19,900 | 24,900 | Plain, heat-treated alloy steel | ASTM F3125/F3125M Grade F1852 and F2280 |
| 3/4-10 | UNC | bolt + twist-off nut + washer | 29,450 | 36,800 | Plain, heat-treated alloy steel | ASTM F3125/F3125M Grade F1852 and F2280 |
| 7/8-9 | UNC | bolt + twist-off nut + washer | 40,750 | 50,950 | Plain, heat-treated alloy steel | ASTM F3125/F3125M Grade F1852 and F2280 |
| 1-8 | UNC | bolt + twist-off nut + washer | 53,450 | 66,800 | Plain, heat-treated alloy steel | ASTM F3125/F3125M Grade F1852 and F2280 |
| 1-1/8-7 | UNC | bolt + twist-off nut + washer | 67,350 | 84,100 | Plain, heat-treated alloy steel | ASTM F3125/F3125M Grade F1852 and F2280 |
| M16 | Metric option | bolt + twist-off nut + washer |  |  | Plain, heat-treated alloy steel | ASTM F3125/F3125M Grade F1852 and F2280 |
| M20 | Metric option | bolt + twist-off nut + washer |  |  | Plain, heat-treated alloy steel | ASTM F3125/F3125M Grade F1852 and F2280 |

Product catalog

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**US$0.024 – 0.048**MOQ 1,000 pieces

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**US$0.12**MOQ 1 piece

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## 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 M16 Tension-Control Structural Bolt Assemblies

Tension-Control Structural Bolt Assemblies are bought for a small number of well-defined jobs. These are the ones we ship them for. Stocked from 1/2-13 to M20 (screw size).

### Industries that specify Tension-Control Structural Bolt Assemblies

- **Industrial fabrication:** One-pass structural assembly where repeatable tension matters more than later disassembly.
- **Steel erection:** Matched structural bolt assemblies tensioned in beam, column and splice connections.
- **Bridge construction:** Slip-critical steel joints where the final tension is set by the twist-off installation system.
- **Heavy transport:** Truck frames and chassis joints exposed to road vibration and cyclic load.
- **Food, pharma & cleanroom:** Stainless assemblies that are washed down, where the finish matters as much as the strength.
- **Machine building & OEM:** The default fastener on production equipment: covers, brackets, motor mounts and sub-assemblies tightened to a specified torque.

### Typical applications

- using the plain shank and heavy hex geometry for steel-to-steel joints
- installing a matched bolt, nut and washer assembly with a controlled twist-off spline
- setting structural tension without a separate torque reaction wrench on the nut
- selecting F1852 or F2280 together with the required installation tension
- joints where the property class is stated on the drawing
- clamping two machined faces to a calculated preload

### Service conditions to specify against

- **Marine and coastal:** Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
- **High load:** Supplied in ISO 898-1 property classes, so the joint can be designed to a stated proof load and tightened to a calculated torque rather than by feel.
- **Torque and preload:** The joint is designed around bolt tension, so lubrication, coating and the friction coefficient all change the torque figure — state them together.

### Where to use something else

- Do not reuse the twisted-off spline or substitute a generic torque value for the grade-specific installation method.
- Do not use a machine thread into unthreaded sheet or timber; use a tapping screw, rivet nut or insert made for that parent material.

[Full application guide: where Tension-Control Structural Bolt Assemblies are used, how to specify them, and the cases they are wrong for](https://engineeringhardware.com/applications/tension-control-structural-bolt-assemblies/)

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 torque do M16 class 8.8 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) take?

A dry M16 class 8.8 joint takes about 209 Nm (≈ 306 Nm for 10.9, ≈ 358 Nm for 12.9). Confirm against your joint design; lubrication reduces these values.

### What clearance and tapping drill suit M16?

Use a 17.5 mm clearance hole (ISO 273 medium) for through-fixing, or a 14 mm tapping drill for a coarse M16 thread.

### What is the coarse-thread pitch of M16 for Tension-Control Structural Bolt Assemblies (TC / Twist-Off)?

For M16 the standard coarse pitch is 2 mm — this is the value used for Tension-Control Structural Bolt Assemblies (TC / Twist-Off).

### 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 Tension-Control Structural Bolt Assemblies (TC / Twist-Off) page](https://engineeringhardware.com/fastener/tension-control-structural-bolt-assemblies/)

### More Tension-Control Structural Bolt Assemblies (TC / Twist-Off) Guides