Carbon cold rolled and hot rolled wire rods are essential materials in the production of fasteners, especially for low-carbon grades such as SWRCH6–16A. These steels are not heat-treated but are used for cold heading and extrusion processes. They are ideal for manufacturing fasteners with lower strength requirements that involve significant deformation and complex shapes. The quality of pickling and phosphating is crucial for these products. When a cold heading deformation exceeds 1/3, annealing is necessary. It is recommended to choose low-carbon grades like SWRCH6A, particularly for large deformation applications. Additionally, customers should select wire material specifications that closely match the required product dimensions to minimize drawing deformation and reduce work hardening effects.
Free return cold rolled steel and hot rolled wire rods have been a focus of innovation in China's steel industry. In 2004, Maanshan Iron & Steel Co., Ltd. participated in the National 863 Program titled "Research on High Performance and Low Cost Cold Rolled Steel" (2003AA331030). This initiative aimed to develop an independent, cost-effective technology for producing cold heading steel wire with online softening capabilities.
High-strength fasteners rated at 8.8 and above typically use medium carbon steel or alloy steel. The production process involves hot rolling, spheroidizing annealing, cold drawing, cold forming, rolling, quenching, and tempering. Spheroidizing annealing improves material plasticity for cold heading, which can involve up to 70–80% total deformation. Raw materials must have low hardness, ideally no more than HRB82. However, spheroidizing annealing is time-consuming and energy-intensive, often taking 12–24 hours in batch or continuous furnaces. As a result, the industry seeks to simplify or eliminate this step, aiming for shorter processing times and even direct use without annealing.
Ma Steel’s high-line technology has developed unique hot-rolling processes with proprietary intellectual property. They have introduced annealed SWRCH35K-M and CH35A-M, as well as SWRCH35K-MT and CH35A-MT wire rods for U.S. fastener exports. These wires are suitable for hex bolts and similar fasteners with moderate cold heading deformation. For larger deformation applications, spheroidizing annealing is still required. For nuts, MFM-1 and MFM-3 wire rods were developed for high-strength nuts, while MFM-2 eliminates both annealing and quenching + tempering, directly producing grade 8 nuts.
Non-tempered cold heading steel is widely used for high-strength fasteners like 8.8, 9.8, and 10.9 bolts. Using non-tempered cold-rolled steel reduces the need for pre-drawing annealing and post-bolting quenching and tempering. This simplifies the production process, shortens the cycle, lowers energy consumption, and avoids issues like surface oxidation and decarburization. Japan has already adopted this technology for mass production.
In 2005, Maanshan Iron & Steel Co., Ltd. took part in the National 863 Program Guided Project “Research and Development of Non-Quenched and Tempered Steel Wire for Low Temperature Controlled Rolling and Controlled Cooling Fasteners†(2005AA001110). In 2008, they also joined the National Support Program Project “Development of Low-Cost, High-Strength Non-Quenched and Tempered Cold-Rolled Steel Products for Steel Structure Joints†(2007BAE30B04). Their non-tempered steel series uses micro-alloying, controlled rolling, and cooling to achieve ultra-fine grain structures. This allows skipping raw material annealing and fastener preparation, meeting current mechanical performance standards (GB/T 3098.22-2009). This new process saves energy, reduces costs, minimizes environmental impact, and avoids defects caused by heat treatment.
Alloy cold heading steels such as 10B21, ML40Cr, and SCM435 are used for high-grade fasteners ranging from 8.8 to 12.9. Through strict process control, these materials offer excellent performance and cost-effectiveness, making them ideal for demanding applications where strength and reliability are critical.
DIN11850 Stainless Steel Sanitary Pipes is the main tubing line for a piping system. Generally, DIN11850 Stainless Steel Sanitary Pipes are made in stainless steel 304 and 316L, but we provide other grade too such as hastelloy C22, 316Ti, Titanium and nickel alloy etc. Kaysen offer both sanitary seamless tubes and Sanitary Welded Tubes to ASTM A270, ASTM A249, A269, ASTM A554, DIN11850, and size is up to 12″. Inner and outer surface is polished to meet the high purity requirement of hygienic industries. Kaysen is ability to supplying qualified DIN11850 Stainless Steel Sanitary Pipes comply to your your condition and FDA,GMP requirement.
DIN11850 Stainless Steel Sanitary Pipes - Polished Stainless Steel Tube – Stainless Steel Hygienic Tubes
Material: SS304, SS316L, EN 1.4301, EN 1.4404, etc
OD diameter: 1/2" - 12"
Thickness: 0.5mm - 6mm
Standard: ASTM, JIS, DIN, JIS, SUS, GB
Length: 6m or customer made
Tolerance: OD. ±0.2mm; Thickness: ±0.02mm; Length: ±0.5mm
Surface Treatment: Matt Finish or Mirror Finish (320# 400# 600#) etc
Application: Boiler, heat exchanger, construction, hygienic, pharmacy, power, petrochemical
Strength:
Heat Treatment of solution annealing for the sanitary tubings and fittings are available
High precision on dimension and wall thickness
Both seamless and welded sanitary tubings are available
Length is up to 12 meters.
Min. order quantity of sanitary tubings is from 300Kgs.
Offer industrial pipe and tubes according to order.
PMI test to verify material grade.
Visual and surface 100% examination before shipment.
End protected for shipment.
DIN11850 Stainless Steel Pipes,DIN Sanitary Tubes,1.4306 Hygienic Pipes
Kaysen Steel Industry Co., Ltd. , https://www.chinasanitaryvalve.com