Black M8 M12 Carbon steel Thumb Screw Class8. 8 Grade 8.8 Spade Head Thumb Screw

Black M8 M12 Carbon steel Thumb Screw Class8. 8 Grade 8.8 Spade Head Thumb Screw

Product Description:

Hand screws (sometimes written thumbscrews) are multi-purpose fasteners designed to be tightened and loosened manually without the need for tools such as screwdrivers or wrenches for installation. They have a wide range of useful applications, especially in parts, materials and structures that do not easily support the use of hand or power tools. This is often due to space constraints.

Hand screws and thumb bolts may also be useful solutions in situations where you may need to remove components or panels on a regular basis. They can make tasks such as maintenance or cleaning quicker and easier than using mechanical screws, bolts or rivets that are fully tightened with a driver.

Various types of fasteners and fixings may fall under the broad definition of hand screws. True hand screws or bolts can be distinguished from standard bolts or rivets by their large heads, which provide an easier grip. They have knurled edges around the head to further improve friction and grip when turned by hand. They may have a screwdriver slot in the head if desired. Washers are usually not required to use this type of fastener.

Knurled Hand Screws
Knurled hand screws are often chosen because they give the user a better grip during manual installation.

These types of knurled bolts and screws are called knurled because of the knurling pattern found around the head of the screw - a series of ridges or bumps formed by machining. Knurling is a widespread manufacturing technique used to improve grip or torque forces between various components and fasteners that are manually installed.

Knurled head hand screws are one of the common applications of this technique and can be found on many stainless steel or nylon nuts, screws and bolts. The pattern of bumps, ridges, or grooves allows for better finger friction against otherwise smooth edges when tightening hand screws.

Hand Screw Knobs
Hand screw knobs, often referred to simply as thumb knobs, are closely related to hand screws. However, they are specifically designed to be used as a quick, easy-to-remove fastening solution to tighten something and release it when needed.

Typical application examples include dashboards, chassis covers, battery compartments, and enclosure windows. Thumb knobs may also be listed as star knobs, depending on the shape of the head designed to be held in the hand.

The head portion of a hand screw knob is usually made of plastic (nylon) or resin (Yuliya resin hand screws are common) and is manufactured as a separate part from the metal portion of the threaded shaft itself. In fact, nylon knurled head knobs can often be purchased separately, with the head designed to be press-fit onto the hand screw for easier installation and removal.

What is the role of hand screws?
Hand screws
Hand screws can be used in a variety of tasks and assemblies. Their primary use is to fasten panels, wiring, covers, safety covers, battery compartments, and any part or assembly that may need to be removed and reinstalled frequently. Cheap hand screws, thumbscrews and thumbscrews are widely available online and are usually sold individually or in bulk.
It is also common to find pre-installed hand screws on a variety of consumer electronics and household appliances. Whilst most are used in some form of plastic or metal assembly, it is not uncommon to see hand screws in specific types of wooden assemblies, due to the specific type of construction, mounting or action they perform making them a suitable choice. Larger sized models are also used in a variety of industrial applications.

Applications:

Carbon Steel
Carbon steel, also known as carbon steel, is an iron-carbon alloy with a carbon content of Wc less than 2%. In addition to carbon, carbon steel generally contains a small amount of silicon, manganese, sulfur, phosphorus.
According to the use of carbon steel can be divided into carbon structural steel, carbon tool steel and free cutting structural steel three categories. Carbon structural steel can be divided into two types of structural steel and machine structural steel.
According to the carbon content of carbon steel can be divided into low carbon steel (Wc ≤ 0.25%), carbon steel (Wc 0.25% 0.6%) and high carbon steel (Wc> 0.6%) according to the phosphorus, sulphur content can be divided into ordinary carbon steel (phosphorus, sulphur, higher), high-quality carbon steel (phosphorus, sulphur, lower) and advanced high-quality steel (phosphorus, sulphur, lower).
The higher the carbon content in general carbon steel, the higher the hardness, the higher the strength, but the plasticity is reduced.

Translated with www.DeepL.com/Translator (free version)

Compared with ordinary steels, special steels have higher strength and toughness, physical properties, chemical properties, biocompatibility and process properties.

Compared with ordinary steel, special steel has high purity, high uniformity, ultra-fine organisation and high precision:
(1) High purity. Targeted reduction of gas, inclusions (including low melting point metal inclusions) in the steel content. The purity of steel to a certain limit, not only can significantly improve the original performance of steel, but also give the steel with new properties. For example, the oxygen content in bearing steel from 30 × 10-6 reduced to 5 × 10-6, the bearing life increased by 30 times. General austenitic stainless steel in the phosphorus reduced to 3 × 10-6 is immune to stress corrosion. the end of the twentieth century, large-scale production of steel can be achieved by the purity level (10) for: hydrogen ≤ 1, oxygen ≤ 5, carbon ≤ 10, sulfur ≤ 10, nitrogen ≤ 15, phosphorus ≤ 25.
(2) high uniformity. Steel composition segregation leads to steel organisation, uneven properties, which is one of the important reasons for the early failure of steel parts and steel performance potential is difficult to give full play to. Modern production processes should make the uniformity of steel to achieve: car gear steel hardenability band fluctuations of ± 3 HRC; the precise level of control of alloying elements for carbon, nickel, molybdenum content of ≤ ± 0.01%, manganese and chromium content of ≤ ± 0.02%; bearing steel quenched grain size of spherical and size fluctuations of 0.8 ± 0.2 μm; resistance to laminar tearing of the longitudinal direction of the steel (z to the steel), the lateral direction of the thickness of the mechanical properties, especially plastic, toughness requirements largely. In particular, the plasticity and toughness requirements are roughly equivalent.
(3) Ultrafine organisation. Ultrafine organisation strengthening is the only strengthening mechanism to increase the strength of steel without reducing the toughness or a slight increase in toughness. For example, high-strength stainless steel AFC77 grain refinement from 60μm to 2.3μm, the fracture toughness KIC from 100 to 220MPa-m. Nuclear reactor pressure vessel steel plate for coarse crystal, its irradiation embrittlement temperature range of 150 ~ 250 ℃ and fine grain steel down to 50 ~ 70 ℃. Bearing steel in the carbide size fine to ≤ 0.5μm, the bearing life is greatly improved.
(4) high precision. Special steel to have good surface quality and narrow dimensional tolerances. The accuracy of hot rolled steel bar has reached ± 0.1mm, hot rolled coil thickness tolerance of ± 0.015 ~ 0.05mm, while the thickness tolerance of cold rolled coil has reached ± 0.003mm.

Oxidation temperature and time for different steel parts:

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Hunan Jiashan Hardware Tech as a branch company of J AND R METALWORK,established in 2007 and located in Changsha, Hunan, China.After almost 17 years management development and technical improvement, Jiashan is willing to be a leading supplier in hardware industry. Meanwhile, we are one of member of Hardware industrial Association and Green energy industry Association.

Jiashan is specialized in milling,turning,lathe 5 axis cnc machining parts,injection molding parts,alumium extrusion parts,laser cutting parts,sheet metal fabrication parts,wire edm parts,vacuum casting parts and fasteners.Those parts are widely service for electric vehicle,solar system,wind power system and construction machinery industry.

During17 years domestic and abroad market investigation, Jiashan's products are sold to many countries and regions including the North America, Europe, Australia, the Middle East and Asia. With owned the advanced cnc machinee, milling machine, polishing machine, stamping machine etc. Jiashan is able to degsin and produce varies OEM parts with drawings or samples provided. Further more, Jiashan also can help to provide a whole solution for modularity R&D of electric vehicle and solar system .

By constantly strengthening our management and consummate the quality guarantee system.In 2023, Jiashan acquired ISO9001:2008 quality certification. Currently,the 5S management mode is implemented in the whole Jiashan system.

Best quality and best service is and will be always our toppest concern.