Zhengzhou Huitong Pipeline Equipment Co.,Ltd.
Zhengzhou Huitong Pipeline Equipment Co., Ltd.
Add to Cart
Stainless steel grades are lumped into classes -- the main ones being austenitic, ferritic, and martensitic. The metalworking powers-that-be developed these classes to consolidate chemical and mechanical properties into categories based on the needs of customers’ uses.
Austenitic steels mainly reside in the 200 and 300 series. Austenitics are the most specified stainless steel grades thanks to their excellent formability and corrosion resistance.
Austenitic stainless steels contain 15%-30% chromium and 2%-20% nickel for better surface quality, corrosion and wear resistance, and workability. They are nonmagnetic when annealed but -- depending on the nickel content and other composition factors --- can become slightly magnetic when cold worked.
You may notice “L” or “H” attached to some of the grades. “L” denotes low carbon content, which equals increased corrosion resistance. “H” denotes high carbon content, a sign of increased strength.
This group of 400-series steels contains 10.5%-20% chromium for corrosion protection and resistance to scaling at high temperatures. Heat treating won’t harden them, and they are always magnetic. Carbon content is low. Ferritic stainless is used in cases where resistance to corrosion is key.
These steels, also of the 400 series, usually contain 11.5%-18% chromium and have higher levels of carbon than their ferritic counterparts. Heat treatment of these steels can result in a wide range of useful hardness and strength levels.
2. ASME B18.2.1 Thread pitch per inch
Coarse Thread Series (UNC/UNRC) is the most common designation for general application bolts and nuts. Coarse thread is beneficial, because they are less likely to cross thread, more tolerant in adverse conditions and facilitate quick assembly.
Fine Thread Series (UNF/UNRF) is commonly used in precision applications. Because of the larger tensile stress areas, they have high tension strength. However, a longer engagement is required for fine thread applications than for coarse series threads to prevent stripping.
8 – Thread Series (8UN) is the specified thread forming method for several ASTM standards including A193 B7, A193 B8/B8M, and A320. This series is used for diameters one inch and above.
| Coarse Thread Series - UNC | Fine Thread Series - UNF | 8-Thread Series - 8UN | |||||||||
| Nominal Size and Threads Per In. | Basic Pitch Dia. | Section at Minor Dia. | Tensile Stress Area | Nominal Size and Threads Per In. | Basic Pitch Dia. | Section at Minor Dia. | Tensile Stress Area | Nominal Size and Threads Per In. | Basic Pitch Dia. | Section at Minor Dia. | Tensile Stress Area |
| In. | Sq in. | Sq in. | In. | Sq in. | Sq in. | In. | Sq in. | Sq in. | |||
| 3⁄8 - 16 | 0.3344 | 0.0678 | 0.0775 | 3⁄8 - 24 | 0.3479 | 0.0809 | 0.0878 | -- -- | -- | -- | -- |
| 7⁄16 - 14 | 0.3911 | 0.0933 | 0.1063 | 7⁄16 - 20 | 0.4050 | 0.1090 | 0.1187 | -- -- | -- | -- | -- |
| 1⁄2 - 13 | 0.4500 | 0.1257 | 0.1419 | 1⁄2 - 20 | 0.4675 | 0.1486 | 0.1599 | -- -- | -- | -- | -- |
| 9⁄16 - 12 | 0.5084 | 0.162 | 0.182 | 9⁄16 - 18 | 0.5264 | 0.189 | 0.203 | -- -- | -- | -- | -- |
| 5⁄8 - 11 | 0.5660 | 0.202 | 0.226 | 5⁄8 - 18 | 0.5889 | 0.240 | 0.256 | -- -- | -- | -- | -- |
| 3⁄4 - 10 | 0.6850 | 0.302 | 0.334 | 3⁄4 - 16 | 0.7094 | 0.351 | 0.373 | -- -- | -- | -- | -- |
| 7⁄8 - 9 | 0.8028 | 0.419 | 0.462 | 7⁄8 - 14 | 0.8286 | 0.480 | 0.509 | -- -- | -- | -- | -- |
| 1 - 8 | 0.9188 | 0.551 | 0.606 | 1 - 12 | 0.9459 | 0.625 | 0.663 | 1 - 8 | 0.9188 | 0.551 | 0.606 |
| 11⁄8 - 7 | 1.0322 | 0.693 | 0.763 | 11⁄8 - 12 | 1.0709 | 0.812 | 0.856 | 11⁄8 - 8 | 1.0438 | 0.728 | 0.790 |
| 11⁄4 - 7 | 1.1572 | 0.890 | 0.969 | 11⁄4 - 12 | 1.1959 | 1.024 | 1.073 | 11⁄4 - 8 | 1.1688 | 0.929 | 1.000 |
| 13⁄8 - 6 | 1.2667 | 1.054 | 1.155 | 13⁄8 - 12 | 1.3209 | 1.260 | 1.315 | 13⁄8 - 8 | 1.2938 | 1.155 | 1.233 |
| 11⁄2 - 6 | 1.3917 | 1.294 | 1.405 | 11⁄2 - 12 | 1.4459 | 1.521 | 1.581 | 11⁄2 - 8 | 1.4188 | 1.405 | 1.492 |
| -- -- | -- | -- | -- | -- -- | -- | -- | -- | 15⁄8 - 8 | 1.5438 | 1.68 | 1.78 |
| 13⁄4 - 5 | 1.6201 | 1.74 | 1.90 | -- -- | -- | -- | -- | 13⁄4 - 8 | 1.6688 | 1.98 | 2.08 |
| -- -- | -- | -- | -- | -- -- | -- | -- | -- | 17⁄8 - 8 | 1.7938 | 2.30 | 2.41 |
| 2 - 41⁄2 | 1.8557 | 2.30 | 2.50 | -- -- | -- | -- | -- | 2 - 8 | 1.9188 | 2.65 | 2.77 |
| 21⁄4 - 41⁄2 | 2.1057 | 3.02 | 3.25 | -- -- | -- | -- | -- | 21⁄4 - 8 | 2.1688 | 3.42 | 3.56 |
| 21⁄2 - 4 | 2.3376 | 3.72 | 4.00 | -- -- | -- | -- | -- | 21⁄2 - 8 | 2.4188 | 4.29 | 4.44 |
| 23⁄4 - 4 | 2.5876 | 4.62 | 4.93 | -- -- | -- | -- | -- | 23⁄4 - 8 | 2.6688 | 5.26 | 5.43 |
| 3 - 4 | 2.8376 | 5.62 | 5.97 | -- -- | -- | -- | -- | 3 - 8 | 2.9188 | 6.32 | 6.51 |
| 31⁄4 - 4 | 3.0876 | 6.72 | 7.10 | -- -- | -- | -- | -- | 31⁄4 - 8 | 3.1688 | 7.49 | 7.69 |
| 31⁄2 - 4 | 3.3376 | 7.92 | 8.33 | -- -- | -- | -- | -- | 31⁄2 - 8 | 3.4188 | 8.75 | 8.96 |
| 33⁄4 - 4 | 3.5876 | 9.21 | 9.66 | -- -- | -- | -- | -- | 33⁄4 - 8 | 3.6688 | 10.11 | 10.34 |
| 4 - 4 | 3.8376 | 10.61 | 11.08 | -- -- | -- | -- | -- | 4 - 8 | 3.9188 | 11.57 | 11.81 |
3. Stainless Steel Bolt Nut Washer package:
