M5 M8 Carbon steel Thumb Screw Galvanized Spade head Thumb screw Blue Zinc coating

M5 M8 Carbon steel Thumb Screw Galvanized Spade head Thumb screw Blue Zinc coating
 
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:

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.

Stainless Steel:
1, the basic knowledge of stainless steel
Stainless steel is an alloy material with corrosion resistance, and its main components are an alloy of elements such as iron, chromium and nickel. These elements can effectively resist oxidation and corrosion, so that stainless steel has a high degree of durability and aesthetics.
2, stainless steel maintenance methods
Cleaning
Keeping stainless steel products clean is an important part of their maintenance. You can use mild detergents and soft cloth for cleaning, avoid the use of detergents containing acidic and alkaline components, so as not to damage the surface of stainless steel. When removing dirt, you should try to avoid using irritating cleaning tools to avoid scratching the stainless steel surface. After cleaning, rinse with water and dry with a clean soft cloth.
3, the use of stain remover
For some stubborn dirt, you can use special stainless steel stain remover for cleaning. But before using it, you should carefully read and follow the instructions in the product manual. In addition, stainless steel products on the dirt can be cleaned with alcohol or vinegar, these common cleaners on stainless steel has a certain decontamination effect.
Steel types:

 
201, 304, 316 are austenitic stainless steel, according to the performance of the non-magnetic, some of the performance of the weak magnetic because of the smelting of the composition of the segregation or improper heat treatment leads to the austenite in a small amount of martensite or ferrite. Austenitic stainless steel corrosion resistance comes from the formation of chromium oxide protective layer on the metal surface. When the material temperature is heated to 450 degrees -900 degrees, the structure changes, will form chromium carbide along the edge of the crystal and can not form a protective layer of chromium oxide, thus reducing the corrosion resistance, this is also known as ‘intergranular corrosion’. As a result, there are 304L and 316L, the two due to the low carbon content also reduces the intergranular corrosion. In particular, the higher susceptibility to intergranular corrosion does not mean that non-low carbon content is more susceptible to corrosion, in a highly chlorinated environment, this susceptibility is also higher.
 
304 stainless steel
304 is a general-purpose stainless steel that is widely used to make equipment and machine parts that require good all-round performance (corrosion resistance and formability). In order to maintain the corrosion resistance inherent in stainless steel, the steel must contain more than 18% chromium, more than 8% nickel content. 304 stainless steel is a grade of stainless steel produced according to the American ASTM standard.

A2 stainless steel and A4 stainless steel, A2 is a class of 304 stainless steel, A4 is a class of 316 stainless steel, the main difference between the two is here, some of the fastener industry will be 302HQ and 304 referred to as: A2, 316 and 316L (C content of carbon C is less than 03% of the stainless steel, you can increase the ‘L’ logo) called A4.

What is the difference between a270 and a470 stainless steel bolts Nuts are usually used in conjunction with bolts. Hexagonal nuts are more widely used.C-grade hexagonal nuts are used in steel structures, machinery and equipment with rough surfaces and low requirements for precision.A-grade and B-grade hexagonal nuts are mainly used in machinery and equipment with smooth surfaces and high requirements for precision.

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