Nut (hardware)
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A nut is a type of hardware fastener with a threaded hole. Nuts are almost always used opposite a mating bolt to fasten a stack of parts together. The two partners are kept together by a combination of their threads' friction, a slight stretch of the bolt, and compression of the parts. In applications where vibration or rotation may work a nut loose, various locking mechanisms may be employed: Adhesives, safety pins or lockwire, nylon inserts, or slightly oval-shaped threads. The most common shape is hexagonal, for similar reasons as the bolt head - 6 sides give a good granularity of angles for a tool to approach from (good in tight spots), but more (and smaller) corners would be vulnerable to being rounding off. Other specialized shapes exist for certain needs, such as wing nuts for finger adjustment and captive nuts for inaccessible areas.
Nuts are graded with strength ratings compatible with their respective bolts; for example, an ISO property class 10 nut will be able to support the bolt proof strength load of an ISO property class 10.9 bolt without stripping. Likewise, an SAE class 5 nut can support the proof load of an SAE class 5 bolt, and so on. The proof strength of the most common property classes is listed at bolted joint.
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[edit] Types
- barrel nut
- cap nut (acorn nut)
- cage nut
- Clip-on nut (J-nut or U-nut)
- coupling nut
- crushed nut
- cross dowel
- flange nut (collar nut)
- insert nut
- Internal wrenching nut (Allen nut)
- knurled nut (thumb nut)
- lug nut
- panel nut
- Plate nut (nut plate)
- PEM nut (for metal)
- Rivet nut or blind nut
- Self-aligning nut
- Sex bolt
- Swage nut
- slotted nut
- split nut
- square nut
- staked/welded nut (for plastic)
- Nut-type MJT
- T-nut
- T-slot nut (T-groove) nut
- weld nut
- well nut
- wing nut
[edit] Locknuts
- Castellated nut
- Distorted thread locknut
- Interfering thread nut
- Jam nut
- Jet nut (K-nut)
- Keps nut (K-nut or washer nut) with a star-type lock washer
- Nyloc plate nut
- Polymer insert nut (Nyloc)
- Serrated face nut
- Serrated flange nut
- Speed nut (Sheet metal nut or Tinnerman nut)
- Split beam nut
[edit] Standard metric hex nuts sizes
| Nominal diameter hole D (mm) |
Pitch P (mm) |
Flat size A/F (mm) |
External diameter A/C (mm) |
Height H (mm) | ||||
|---|---|---|---|---|---|---|---|---|
| 1st choice |
2nd choice |
coarse | fine | Hex Nut | Jam Nut | Nylon Nut | ||
| 1 | 0.25 | |||||||
| 1.2 | 0.25 | |||||||
| 1.4 | 0.3 | |||||||
| 1.6 | 0.35 | |||||||
| 1.8 | 0.35 | |||||||
| 2 | 0.4 | 4 | 1.6 | 1.2 | - | |||
| 2.5 | 0.45 | 5 | 2 | 1.6 | - | |||
| 3 | 0.5 | 5.5 | 6.4 | 2.4 | 1.8 | 4 | ||
| 3.5 | 0.6 | |||||||
| 4 | 0.7 | 7 | 8.1 | 3.2 | 2.2 | 5 | ||
| 5 | 0.8 | 8 | 9.2 | 4 | 2.7 | 5 | ||
| 6 | 1 | 0.75 | 10 | 11.5 | 5 | 3.2 | 6 | |
| 7 | 1 | 11 | 5.5 | 3.5 | - | |||
| 8 | 1.25 | 1 | 13 | 15 | 6.5 | 4 | 8 | |
| 10 | 1.5 | 1.25 or 1 | 17 | 19.6 | 8 | 5 | 10 | |
| 12 | 1.75 | 1.5 or 1.25 | 19 | 22.1 | 10 | 6 | 12 | |
| 14 | 2 | 1.5 | 22 | 11 | 7 | 14 | ||
| 16 | 2 | 1.5 | 24 | 27.7 | 13 | 8 | 16 | |
| 18 | 2.5 | 2 or 1.5 | 27 | 15 | 9 | 18.5 | ||
| 20 | 2.5 | 2 or 1.5 | 30 | 34.6 | 16 | 10 | 20 | |
| 22 | 2.5 | 2 or 1.5 | ||||||
| 24 | 3 | 2 | 36 | 41.6 | 19 | |||
| 27 | 3 | 2 | ||||||
| 30 | 3.5 | 2 | 46 | 53.1 | 24 | |||
| 33 | 3.5 | 2 | ||||||
| 36 | 4 | 3 | 55 | 63.5 | 29 | |||
| 39 | 4 | 3 | ||||||
| 42 | 4.5 | 3 | ||||||
| 45 | 4.5 | 3 | ||||||
| 48 | 5 | 3 | ||||||
| 52 | 5 | 4 | ||||||
| 56 | 5.5 | 4 | ||||||
| 60 | 5.5 | 4 | ||||||
| 64 | 6 | 4 | ||||||
[edit] Classifications
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This section requires expansion. |
| Material | Proof strength | Tensile yield strength (min.) | Tensile ultimate strength (min.) | Nut marking | Nut class | ||
|---|---|---|---|---|---|---|---|
| ISO 898 | |||||||
| Low or medium carbon steel | 380 MPa (55 ksi) | 420 MPa (61 ksi) | 520 MPa (75 ksi) |  |
5 | ||
| Medium carbon steel Q&T | 580 MPa (84 ksi) | 640 MPa (93 ksi) | 800 MPa (116 ksi) |  |
8 | ||
| Alloy steel Q&T | 830 MPa (120 ksi) | 940 MPa (136 ksi) | 1040 MPa (151 ksi) |  |
10 | ||
| SAE J429 | |||||||
| Low or medium carbon steel | 55 ksi (379 MPa) | 57 ksi (393 MPa) | 74 ksi (510 MPa) |  |
2 | ||
| Medium carbon steel Q&T | 85 ksi (586 MPa) | 92 ksi (634 MPa) | 120 ksi (827 MPa) |  |
5 | ||
| Alloy steel Q&T | 120 ksi (827 MPa) | 130 ksi (896 MPa) | 150 ksi (1034 MPa) |  |
8 | ||
