Stainless steel screw is a standard fastener, mainly made of stainless steel wire and steel bar, and other materials.

Stainless steel screw is a standard fastener, mainly made of stainless steel wire and steel bar, and other materials. The following are its characteristics:

1. Stainless steel screws are more resistant to corrosion than ordinary carbon steel screws, which is due to the chromium element in stainless steel that can effectively resist the corrosion of the parts by the atmosphere, water, and other media, thus prolonging their service life.

2. Stainless steel screws are also highly resistant to acidity, alkalinity, and salt, and therefore they are widely used in the chemical industry, food industry, and other fields.

3. Stainless steel screws have good strength and toughness, and can withstand high stress and impact loads, and are suitable for the assembly and repair of various machinery and equipment.

4. Stainless steel screws have smooth surfaces and high dimensional accuracy, which enables them better to fit the surface of the parts during fastening and improve the fastening effect.5. Stainless steel screws are usually supplied with standard specification threads such as M, UNC, BSW, etc. They can be used with ordinary nuts, bolts, and other fasteners, making them convenient for users. It should be noted that stainless steel screws are not suitable for all environments and occasions because they are relatively expensive, and different stainless steel materials have different performance characteristics, which need to be selected according to the actual situation.

The material classification of stainless steel screws has austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, and precipitation hardening stainless steel. The selection of stainless steel screws also has the principle of what to start from so that you can choose the stainless steel screws you need. Through these five aspects of a comprehensive, comprehensive consideration, finally determine the selection of stainless steel screws grade, variety, specifications, and material standards.

Austenitic stainless steel: austenitic stainless steel is the most basic alloying elements of chromium and nickel, representative of the grade is containing chromium for about 18%, containing nickel for about 8% of chromium a nickel austenitic stainless steel, often called 18 -8 stainless steel. The elemental ratio of chromium and nickel ensures that the steel's organization is stable austenite.

Ferritic stainless steel: 430-type ordinary chromium steel, its corrosion resistance and heat resistance than 410-type good, magnetic, but it is not able to heat treatment to strengthen, applicable to the corrosion resistance and heat resistance is slightly higher, the strength requirements of general stainless steel stainless steel screws.

18-8 Stainless Steel Thread-Locking Socket Head Screws： Made from 18-8 stainless steel, these screws have good chemical resistance and may be mildly magnetic. A thread locker bonded to the threads adds friction to resist loosening from vibration. Dimensions meet ASME B18.3 or ISO 4762 (formerly DIN 912) specifications， Length is measured from under the head.

Screws with a nylon patch are reusable, but their holding power lessens with each use. Screws with an epoxy adhesive provide a permanent bond; once tightened, the epoxy expands to seal the gaps between the mating threads.

Metric screws are also known as A2 stainless steel screws.

Coarse threads are the industry standard; choose these screws if you don’t know the pitch or the threads per inch. Fine threads are closely spaced to prevent loosening from vibration. They are not compatible with coarse threads.

Metric 18-8 Stainless Steel Button Head Hex Drive Screws： Made from 18-8 stainless steel, these button head screws have good chemical resistance and may be mildly magnetic. Length is measured from under the head.

Passivated stainless steel screws provide added protection against oxidation and corrosion.

Black-oxide stainless steel screws have a matte-black finish.

18-8 Stainless Steel, Pan Head Slotted Screws：18-8 stainless steel pan head screws have good chemical resistance and may be mildly magnetic. All are passivated for added protection against oxidation and corrosion. Length is measured from under the head.

18-8 Stainless Steel Narrow Cheese Head Slotted Screws： More corrosion resistant than steel and almost as strong, these 18-8 stainless steel screws have a narrower head than pan head screws to fit into tight spaces. They’re often used in electrical panels and next to flanges and raised surfaces in humid, damp, and washdown environments but will rust if exposed to salt water or chemicals. A deep slot gives you more driving power and keeps the screwdriver from slipping. Length is measured from under the head.

Passivated screws are finished with an extra layer of rust protection.

Screws with an extended tip, sometimes called an entire dog point, fit into a hole or slot to keep parts such as pulleys and gears aligned. Use these screws in place of dowel pins; their threads clamp your parts down and keep them from rotating.

NAS 721 screws meet National Aerospace Standards. ISO 1207 (formerly DIN 84), DIN 920, and DIN 922 screws meet international standards for fastener dimensions.

18-8 Stainless Steel Decorative Round Head Slotted Screws：18-8 stainless steel screws have good chemical resistance and may be mildly magnetic. All are passivated for added protection against oxidation and corrosion. These screws have a tall, domed head that provides a finished appearance. Length is measured from under the head.

Metric 18-8 Stainless Steel Button Head Torx Screws：18-8 stainless steel screws have good chemical resistance and may be mildly magnetic. All are passivated for added protection against oxidation and corrosion. A Torx drive has more points of contact than other drives, allowing you to tighten the screw without damaging the recess. For Torx tools, see Torx bits, keys, and drivers. Length is measured from under the head.

18-8 Stainless Steel Flanged Button Head Screws：18-8 stainless steel screws have good chemical resistance and may be mildly magnetic. The flange distributes pressure across a wide surface, eliminating the need for a separate washer. Head height includes the flange. Length is measured from under the flange.

Passivated stainless steel screws provide added protection against oxidation and corrosion.

Martensitic stainless steel: 410 and 416 types can be heat treated to strengthen the hardness of 35 ~ 45HRC, good machinability for general purposes of heat-resistant corrosion-resistant stainless steel screws.

416-type sulfur content is slightly higher and is easy to cut stainless steel. 420-type, sulfur content ?R0.15%, mechanical properties to improve, can be heat-treated to strengthen the maximum hardness value of 53 ~ 58HRC, used for the requirements of higher strength stainless steel screws.

Precipitation hardening stainless steel: 17-4PH, PH15-7Mo, they can get higher strength than the usual 18-8 type stainless steel, and thus are used for high strength, corrosion-resistant stainless steel stainless steel screws.

A-286, non-standard stainless steel, than the usual 18-8 type stainless steel, has higher corrosion resistance and, in the temperature increase, still has good mechanical properties. Used as high strength, heat resistant, corrosion resistant stainless steel screws, can be used to 650 ~ 700 ℃.

Austenitic stainless steel: commonly used models for 302, 303, 304, and 305 four models, the so-called "18-8" type austenitic stainless steel these four models. Whether it is corrosion resistance or its mechanical properties are similar. The starting point for the selection of stainless steel screws is the production process method, and the method depends on the size and shape of the stainless steel screws but also depends on the number of production.

Type 302 is used for screws and self-tapping bolts that are machined.

Type 303 is used for nuts machined from bar stock. A small amount of sulfur is added to the stainless steel to improve cutting performance.

Type 304 is used for the machining of stainless steel screws using the hot heading process, such as longer bolts and large diameter bolts, which may be beyond the scope of the cold heading process.

Type 305 is suitable for processing stainless steel screws by cold heading processes, such as cold-formed nuts and hexagon bolts.

Types 309 and 310, with higher Cr and Ni content than 18-8 stainless steel, are suitable for stainless steel screws working at high temperatures.

Type 316 and 317 all contain the alloying element Mo, so their high-temperature strength and corrosion resistance are higher than those of 18-8 type stainless steel.

Type 321 and 347, type 321 contains the more stable alloying element Ti, and type 347 contains Nb, which improves the material's resistance to intergranular corrosion. It is suitable for stainless steel standard parts not annealed after welding or in service at 420～1013℃.For high-quality 18-8 Stainless Steel Button Head Torx Screws for Sheet Metal and professional technical support, don't hesitate to contact us at adelajonly@gmail.com or visit our website at: https://www.juxinfasteners.com.