Weimi Hardware Technology Co. Ltd. is a professional precision machining manufacturer. We can process parts and components using various materials according to customers’ drawings and design requirements, and provide a fast and cost-effective way to produce high-quality metal and plastic parts. The most common materials we use are aluminium, stainless steel, brass, and POM and rubber.
Aluminium is the most widely used non-ferrous metal material, and its application scope is still expanding. There are many grades of aluminium that can be used in production and over the years, demand has risen across the world – particularly in the construction and transportation industries (including aerospace and aviation).
In general, the material grades required by foreign customers are aluminium 6061, aluminium 6063, and aluminium 7075, as they have good plasticity and are suitable for all kinds of cold and hot forming. They can be machined at high speed, e.g. turning and milling.
Weimi can ensure that all machined surfaces and parts are manufactured to the highest quality, with all CNC parts having an allowance of 0.2-0.5mm in any direction. We can achieve this by using a stable and sharp cutter that reduces deformation and provides a good surface finish and accuracy. Our products can be very shiny and smooth even without surface treatment – something which we have become known for by our clients.
We also work with stainless steel, which is more difficult to machine because it’s more prone to breaking during the cutting process. Depending on the grade and characteristics of each steel sample, Weimi optimises the production technique, taking into account cutting materials, cutting parameters, and cooling methods. Alongside this, we usually choose carbide cutting tools for machining stainless steel, and pay attention particular attention to the speed and feed rate. Stainless steel is commonly used in a variety of mechanical parts as well as in the axle and food medical industries.
Another commonly required metal processing material is brass, which is quite a brittle material. It is easy to cut, but when machining, the turning tool should be installed very accurately to ensure a precise and sharp cutting edge. Our technicians will also not clamp too tightly on the machined part, and instead will move slowly and then add some coolant to ensure the machining finish is completed to the highest standards. Alongside this, brass has a large thermal deformation so before measuring the size of the finished product, the part will be cooled down and then measured for increased accuracy. Most of our customized brass parts are used in 3D printer accessories, connectors, nozzles and other products.
In addition to metal materials, we also manufacture parts made from polyoxymethylene (POM). This kind of material is easy to cut but its thermal stability is poor. When the temperature exceeds 250℃, the decomposition speed will be accelerated, resulting in damage to the material, making it unusable. To effectively avoid deformation, our factory will select pre-select the highest quality raw materials to ensure they are suitable for the production process.
Alongside this, POM is difficult to work with as clamping changes its shape, so additional care must be taken when clamping and loosening the parts to ensure the precision of the overall shape. Weimi adopts multiple cutting processes to overcome this: first, we must ensure the consistency of the CNC part’s dimensions to effectively control our tolerance for deformation during clasping. And then we must be careful when cutting the part as initial contact with the tool will cause it to deform inward due to the elasticity of the material when pressure is applied.
Therefore, when Weimi processes POM products, it is necessary to adjust the tool compensation several times according to the actual cutting effect when it first uses the CNC programming. POM and similar materials are often used in the light industry, automobiles, building materials, agriculture and other fields.
Finally, Weimi ensures that all materials we use are 100% authentic. We can provide material certificates and SGS reports, as well as raw materials for inspection, alongside all parts being 100% inspected by our quality control department – we aim to complete the machining work beyond your quality expectations.
Classification of Machining Materials
As far as machining materials are concerned, they are generally divided into metal materials and non-metal materials. Metal materials can be divided into ferrous metals and non-ferrous metals. Metal material is the general name of all metals and their alloys.
In the modern industrial society represented by steel, iron and alloy, metal material has become a major mainstream material in modern product design due to its excellent mechanical properties, processing properties and unique surface characteristics. The properties of metals are determined by the properties of their bonds.
The properties of metals are shown in the following aspects: (1) metal materials are almost all solid materials with a lattice structure, (2) metal materials are good conductors of electricity and heat, with good ductility, (3) metals can be made into intermetallic compounds, which can form alloys with other metals or non-metals such as carbon, nitrogen, oxygen in the molten state to improve the performance of metals. Alloys can be divided into binary alloys according to the number of added elements.
Ferrous metal: with iron, manganese, chromium or with them as the main form of metal characteristics of the material, known as ferrous metal, such as steel, pig iron, ferroalloy, cast iron and so on.
Steel is a kind of iron-carbon alloy. It is called steel when the carbon content is less than 2%. Steel has high strength, toughness and plasticity, and can be improved by heat treatment. In addition to this, steel non-standard machining parts can be obtained by forging, stamping, welding or casting, so they are widely used.
Depending on the use of steel, it can be divided into structural steel, tool steel and special steel. Structural steel is used to manufacture various mechanical parts and components of engineering structure; tool steel is mainly used to manufacture various cutting tools, molds and measuring tools; special steel (such as stainless steel, heat-resistant steel, acid-resistant steel, etc.) is used to manufacture parts working in a special environment.
According to the chemical composition of steel, it can be divided into carbon steel and alloy steel. The properties of carbon steel mainly depend on the carbon content. The higher the carbon content, the higher the strength, but the lower the plasticity.
In non-standard machining, the use of steel specially added with some alloy elements is called alloy steel, which aims to improve the performance of steel. For example, nickel can improve the strength without reducing the toughness of steel; chromium can improve the hardness, high-temperature strength, corrosion resistance and wear resistance; manganese can improve the wear resistance, strength and toughness of steel.
The influence of alloy elements on steel is very complex, especially when several alloy elements are added at the same time to improve the properties of steel. It should be noted that the excellent properties of alloy steel depend not only on the chemical composition but also to a greater extent on the proper heat treatment.
In addition to iron and carbon in steel, other alloy elements are added, which is called alloy steel. An iron-carbon alloy formed by adding one or more alloying elements to common carbon steel. Depending on the different added elements and the proper processing technology, special properties such as high strength, high toughness, wear resistance, corrosion resistance, low-temperature resistance, high-temperature resistance and non-magnetism can be obtained.
There are many kinds of alloy steels and they are usually divided into low alloy steel (content < 5%), medium alloy steel (content 5% ~ 10%) and high alloy steel (content > 10%) according to the content of alloy elements. Depending on the quality, it can be divided into high-quality alloy steel and special alloy steel; according to the characteristics and uses, it can be divided into alloy structural steel, stainless steel, acid-resistant steel, wear-resistant steel, heat-resistant steel, alloy tool steel, rolling bearing steel, alloy spring steel and special performance steel (such as soft magnetic steel, permanent magnetic steel and non-magnetic steel) etc.
Difference between alloy steel and carbon steel:
Alloy steel contains more other elements than carbon steel. Alloy steel is a kind of steel that contains not only silicon and manganese as alloy elements or deoxidizing elements but also other alloy elements and some non-metallic elements. According to the content of alloy elements in steel, it can be divided into low alloy steel, medium alloy steel and high alloy steel.
While carbon steel mainly refers to the steel whose mechanical properties depend on the carbon content in the steel and generally does not add a lot of alloy elements, sometimes it is also called ordinary carbon steel or carbon steel.
Carbon steel, also known as steel with carbon elements, contains less than 2% of WC iron-carbon alloy. In addition to carbon, carbon steel generally contains a small amount of silicon, manganese, sulfur and phosphorus. Depending on the purpose, carbon steel can be divided into three categories: carbon structural steel, carbon tool steel and free cutting structural steel. According to carbon content, carbon steel can be divided into low carbon steel (WC ≤ 0.25%), medium carbon steel (WC 0.25% – 0.6%) and high carbon steel (WC > 0. 6%). Generally, the higher the carbon content, the higher the hardness, the higher the strength, but the lower the plasticity.
The following are some of the most commonly used metals for machining:
(1) 304 is a kind of universal stainless steel, which is also food grade. It is widely used in the manufacturing of equipment and parts requiring good comprehensive performance (corrosion resistance and formability) and the food and medical industries.
(2) 316L is austenitic stainless steel, and the intergranular corrosion resistance of 316L steel can be significantly improved by adding molybdenum element based on 304.
(3) Q235 is low carbon steel, which is steel with a carbon content of less than 0.25%. Because of its low strength, low hardness and softness, it is also called mild steel. It includes the most common carbon structural steel and some high-quality carbon structural steel. Most of them are used for engineering structural parts without heat treatment, and some are used for mechanical parts requiring wear resistance after carburizing and other heat treatment.
The annealed structure of low carbon steel is ferrite and a small amount of pearlite, with low strength and hardness, good plasticity and toughness. Therefore, it has good cold formability and can be cold formed by crimping, bending, stamping and other methods. The steel also has good weldability.
Low carbon steel with carbon content ranging from 0.10% to 0.30% is easy to accept all kinds of processing such as forging, welding and cutting. It is commonly used for manufacturing chains, rivets, bolts, shafts, etc.
(4) No. 45 Steel: this steel is the most commonly used medium carbon quenched and tempered steel. No. 45 represents that the average carbon content of this steel is 0.45%, with good comprehensive mechanics and low hardenability. It is mainly used to manufacture high-strength sports parts. To meet different processing requirements, there are two types of materials: bar and plate.
Medium carbon steel is a kind of carbon steel with a carbon content of 0.25% – 0.65%. It includes most high-quality carbon structural steel and some ordinary carbon structural steel. This kind of steel is mostly used to make medium carbon steel with good hot working and cutting performance and poor welding performance. The strength and hardness are higher than that of mild steel, but the plasticity and toughness are lower than that of mild steel.
Cold-rolled and cold drawn materials can be used directly without heat treatment or after heat treatment. The medium carbon steel after hardening and tempering has good comprehensive mechanical properties. The highest hardness is about HRC55 (hb538) and σ B is 600-1100mpa. Therefore, medium carbon steel is widely used in all kinds of medium strength applications. In addition to being used as building materials, it is also widely used in manufacturing various mechanical parts. High strength medium carbon quenched and tempered steel has certain plasticity, toughness and strength, good machinability, good comprehensive mechanical properties after quenching and tempering treatment, poor hardenability, easy to produce cracks, low welding performance, good preheating before welding, and heat treatment after welding.
Medium carbon steel is mainly used for manufacturing high-strength moving parts, such as air compressor, pump piston, steam turbine impeller, heavy machinery shaft, worm, gear, etc., surface wear-resistant parts, crankshaft, machine spindle, drum, fitter tools, etc.
(5) 65Mn, No. 75 steel, this steel is high carbon steel, also known as tool steel, with carbon content from 0.60% to 1.70%, which can be quenched and tempered. Hammers and crowbars are made of steel with a carbon content of 0.75%; cutting tools such as drills, taps and reamers are made of steel with a carbon content of 0.90% to 1.00%.
After proper heat treatment or cold drawing hardening, high carbon steel has high strength and hardness, high elastic limit and fatigue limit. Its cutting performance is acceptable, but its welding performance and cold plastic deformation ability are poor. Because of the high carbon content, cracks are easy to occur in water quenching, so double liquid quenching is often used, and oil quenching is often used for small section parts. This kind of steel is usually used after quenching by medium temperature tempering or normalizing or surface quenching. It is mainly used to make springs and wear-resistant parts.
Carbon tool steel is a kind of high carbon steel without alloying elements. It is also a kind of steel with low cost, good hot and cold workability and a wide application range. Its carbon content is 0.65-1.35%, which is specially used for making tools. The density of high carbon steel is 7.81g/cm3. It can be used in the production of fishing gear.
(6) 1015 carbon steel: it has high plasticity and toughness, but low strength and hardness, good forging, welding and cold stamping performance, and high cold deformation plasticity. It is used for manufacturing carburized parts, fastening parts and low load parts without heat treatment, such as screws, bolts, flange plates, etc. for mechanical components.
(7) 1215 steel: easy to cut, environmentally friendly material. Compared with 12L14, it does not contain lead or harmful substances to the environment. It is mainly used for making instruments, watch parts, automobiles, machine tools and other machines with small stress and strict requirements on size and finish. It has strict requirements on size accuracy and finish, and relatively low requirements on mechanical properties, such as gears shaft, bolt, valve, bushing, pin, pipe joint, spring seat cushion and machine lead screw, plastic molding mold, surgical and dental instruments, etc.
(8) 1018 steel: a kind of carbon steel with a carbon content of about 0.05% – 0.70%. It has many uses and large consumption. It is mainly used in railway, bridge and various construction projects to manufacture various metal components bearing static load and unimportant mechanical parts and general weldments that do not need heat treatment.
(9) No. 40 steel: high strength, good machinability, medium cold deformation ability, poor weldability, no tempering brittleness, low hardenability, easy to crack by raw water quenching. After surface quenching, it can be used to manufacture parts with large stress. It is suitable for manufacturing crankshaft mandrel, transmission shaft, piston rod, connecting rod, sprocket, gear, etc.
Non-ferrous metals: metals and alloys other than ferrous metals. In a narrow sense, non-ferrous metals include all metals except iron, manganese and chromium. The commonly used non-ferrous metals are aluminium and aluminium alloy, copper and copper alloy, titanium and titanium alloy, magnesium and magnesium alloy, hard alloy, etc.
In a broad sense, non-ferrous metals also include non-ferrous alloys. A non-ferrous alloy is a kind of alloy that takes a non-ferrous metal as the matrix (usually more than 50%) and adds one or several other elements. Non-ferrous metals generally refer to all metals except iron (and sometimes manganese and chromium) and iron-based alloys. Non-ferrous metals can be divided into heavy metals (such as copper, lead, zinc), light metals (such as aluminium, magnesium), precious metals (such as gold, silver, platinum) and rare metals (such as tungsten, molybdenum, germanium, lithium, lanthanum, uranium).
The following metals are common materials during processing:
(1) Aluminium 1050A, 1060: pure aluminium plate, commonly used for panel without bearing force, industrial pure aluminium, with high plasticity, conductivity and thermal conductivity but low strength, can be used for parts of aircraft ventilation system, capacitors, etc.
(2) Aluminium 5083, aluminium 5056: aluminium magnesium system antirust aluminium with high magnesium content, beautiful surface after anode treatment, 5083 is mainly used for bicycle back cover, 5056 is mainly used for handlebars, girders and other structural parts. These two kinds of secondary materials can be used in ships, aeroplanes, automobiles and so on.
(3) Aluminium 6061 and 6063 are common metals in processing. The main alloy elements are magnesium and silicon, which have medium strength, good corrosion resistance and good oxidation effect. They are widely used in various industrial structural parts requiring certain strength and high corrosion resistance;
(4) 7075 aluminium alloy is a kind of cold-treated forging alloy. Zinc is the main alloy element in 7075, with high strength, far superior to mild steel. It has common corrosion resistance, good mechanical properties and anode reaction. It is used to make high-end aluminium alloy bicycle frame, marine plate, mold processing, etc.
(5) 5005 has medium strength and good corrosion resistance. It is used as a conductor, cooker, building decoration, etc. 5050 thin plates can be used as the inner lining plate of a refrigerator, automobile pipe, and can also process thick plate, pipe, profile, etc.
(6) 2024 aluminium alloy is a kind of hard aluminium with high strength. It belongs to the Al-Cu-Mg system. It is mainly used to make various parts and components with a high load. It can be heat-treated and strengthened. Its plasticity is medium under quenching and rigid quenching.
(7) 2A70 aluminium alloy is a kind of aluminium alloy, which has the characteristics of high plasticity, easy forging and punching.
(8) Brass is a copper alloy with zinc as the main additive, high strength, strong wear resistance, used for hardware, mechanical parts, gasket, etc.
(9)Titanium alloy has the characteristics of steel like appearance, silver-grey lustre, high strength, good corrosion resistance and high heat resistance. Titanium alloy is mainly used for making compressor parts of aircraft engine, followed by structural parts of rocket, missile and high-speed aircraft.
In addition, most of the metal parts need to use heat treatment to enhance the stiffness, strength and more. Heat treatment refers to a kind of metal hot working process in which materials are heated, insulated and cooled in a solid state to obtain the expected structure and properties.
Annealing: annealing is a kind of heat treatment method that heats the steel to a certain temperature, holds it for a certain period of time, and then cools it slowly in the furnace to obtain a nearly balanced structure. Annealing can reduce the hardness of steel to facilitate cutting. Refine the experience of tracking to improve organization and performance. Increase plasticity and toughness of steel. Eliminate internal stress. Prepare for quenching. Annealing includes complete annealing, spheroidizing annealing and stress relief annealing. Complete annealing is the most common.
Normalizing: normalizing is heating the steel to a certain temperature. After holding for a certain time. The process of cooling in the air. There are many similarities between normalizing and return. But normalizing cools faster. The hardness and strength of normalized steel are slightly higher than that of annealed steel. Normalizing is often used for the final heat treatment of common components, such as screws, unimportant shafts and other CNC parts.
Quenching: quenching is a heat treatment method to heat the steel to a certain temperature and cool it rapidly in water and oil after heat preservation. Quenching heat treatment can improve the hardness, strength and service life of materials. Various tools, dies, and many important parts need to be hardened to improve their mechanical properties.
Tempering: tempering is a treatment method of reheating the quenched steel to a certain temperature and cooling it in the air after heat preservation. To reduce the internal stress, reduce the brittleness and adjust the hardness of quenched CNC parts, tempering must be carried out after quenching. According to the different tempering temperature, it can be divided into low-temperature tempering, medium temperature tempering and high-temperature tempering.
Surface heat treatment is divided into the following two types:
Surface hardening: flame hardening, induction hardening.
Chemical heat treatment: carburizing, nitriding, carbonitriding.
The heat treatment process is an important way to improve the life of parts. Different parts need different heat treatment.
Generally, it refers to glass, ceramics, graphite, rock with inorganic materials as the main body and wood, plastic, rubber and other materials with organic materials as the main body. The commonly used processing materials are as follows:
Rubber: rubber is divided into natural rubber and synthetic rubber. It has high elasticity, wear-resistance and insulation. It is used as a dynamic and static seal, shock absorption and various wear-resistant parts,
Plastics: most of them are light in weight, stable in chemical properties, corrosion-resistant and impact-resistant; they have good transparency and wear resistance; they have good insulation and low thermal conductivity; they are generally good in molding, coloring and processing cost; most of them have poor heat resistance, large thermal expansion rate and easy to burn; they have poor dimensional stability and are easy to deform. However, these kinds of plastics are widely used:
PP material (polypropylene) is a very safe and light-weight plastic material, with good heat resistance, a unique lustre on the surface and easy to be processed to show bright colors; due to the high bending strength, some types of materials will often be preferred in the production of integrated containers (like some containers with box covers and box bodies). PP plastic box is also a transparent packaging box made of this kind of plastic as raw materials, which is often used in the packaging of some baby products.
PVC material (PVC), the biggest characteristic of PVC material is that it can be added with different additives to make various kinds of soft and hard goods with different texture and different purposes, with strong plasticity. PVC material has low cost, good transparency, and very good flexibility. It is suitable for making all kinds of Blister products and PVC packing boxes.
PET material (polyethylene terephthalate) is the material that we often see made of Baote bottle. PET can also be used as fiber. The biggest feature of PET is that it has a complete recycling system. Because of its environmental protection and safety, this high-efficiency material is widely used in the plastic box and blister packaging industry.
ABS resin, with higher strength than PS, has a very good fluidity during molding, and is a very common material used in the injection molding industry.
PA nylon, also known as polyamide, is the first synthetic fiber in the world. Its most outstanding advantage is that its wear resistance is higher than all other fibers. This kind of product has a wide range of uses. It is a good material to replace steel, iron, copper and other metals with plastics. It is an important engineering plastic. It is suitable for making wear-resistant parts, transmission structure parts, household electrical parts, automobile manufacturing parts, chemical machinery parts, teeth and so on wheel, bearing, high-pressure washer, etc.
Polyformaldehyde: POM, known as «super steel» or «saigang», is a hard and compact material with a smooth and glossy surface, good elasticity and wear resistance. POM has been widely used in electronic and electrical, machinery, instrument, daily light industry, automobile, building materials, agriculture and other fields.
Acrylic, also known as PMMA or plexiglass, is an important plastic polymer material. With good transparency, chemical stability and weather resistance, easy to dye, easy to process, beautiful appearance, it is widely used in the construction industry. Its forming methods include casting, injection molding, machining, thermoforming, etc. It is also widely used in instrument parts, automobile lamps, optical lenses, transparent pipes, etc.
Polytetrafluoroethylene: Teflon, referred to as PTFE, has the characteristics of high-temperature resistance. Polytetrafluoroethylene can be processed by compression or extrusion; polytetrafluoroethylene is widely used in the industries of atomic energy, national defence, aerospace, electronics, electrical, chemical, machinery, instrument, architecture, textile, metal surface treatment, pharmaceutical, medical, textile, food, metallurgy and smelting, etc. Corrosion-resistant materials, insulating materials, anti-sticking coating, etc.