Material requirements for stainless steel bolts, screws, and nuts

2023-05-22 15:03:43

1) The content of boron can reach 0.005%, and its non effective boron can be controlled by adding titanium and/or aluminum.

2) These performance grade stainless steel nuts allow for easy cutting manufacturing, with a maximum content of sulfur, phosphorus, and lead of 0.34% sulfur; Phosphorus 0.11%; 0.35% lead.

3) To ensure good hardenability, stainless steel fasteners with a diameter exceeding 20mm require the use of steel specified for grade 10.9.

4) The minimum manganese content of low-carbon alloy steel with a carbon content lower than 0.25% (barrel analysis) is 8.8 grade: 0.6%; Levels 9.8, 10.9, and 10.9: 0.7%.

5) The product should be marked with a horizontal line under the performance level code. Level 10.9 should meet all the performance requirements specified for level 10.9, while lower downstream temperatures will cause varying degrees of stress weakening under the conditions of elevated temperatures.

6) The materials used for this performance level shall have good hardenability to ensure that the core of the thread section of stainless steel fasteners can obtain about 90% martensite structure after quenching and before tempering.

7) Alloy steel should contain at least one of the following elements, with a minimum content of 0.30% chromium; 0.30% nickel; Molybdenum 0.20%; Vanadium 0.10%

8) Considering bearing tensile stress, white phosphorus accumulation layer that can be detected by metallography is not allowed on the surface of grade 12.9.

9) The chemical composition and tempering temperature are still under investigation and research for stainless steel standard parts.