Sheet Metal Processing Design Notes & Capability

Available materials of Sheet-Metal Process

*A single sheet is generally [ length × width: 2440~2500 × 1220~1250 mm] (can be cut to any size according to needs)
* Weight calculation: length (m) × width (m) × thickness (m) × density (kg/m³) = kilogram (kg)
Note: 1. The general tolerance of material thickness is +0, -0.08. This negative tolerance gradually increases as the thickness of the plate increases.
2. A micrometer/micrometer should be used to measure the thickness of the material, not a caliper.

Material / Code	Thickness	Tensile Strength	Material-Surface	Available Model	Density
Cold rolled plate/SPCC	0.8/1.0/1.5/2.0/2.5/3.0/4.0/5.0/6.0	Above 28kgf/mm	Glossy	/	7.85KG/㎡
characteristic	1. Iron-gray luster, the surface is easy to scratch and rust, so you must pay attention to protection and quickly turn the order during processing. 2. Suitable for electroplating (color zinc plating, white zinc plating, blue zinc plating, nickel plating, electrophoresis, blackening), baking paint, powder spraying... etc.
Hot rolled plate/Q235	0.8/1.0/1.5/2.0/2.5/3.0/4.0/5.0/6.0	Above 41~52kg/mm	Glossy	/	7.85KG/㎡
characteristic	1. Black-gray luster, the surface is not easy to be scratched, but it is easy to rust spots, so you must pay attention to it 2. Suitable for baking paint, powder spraying, etc.
Galvanized sheet/SECC	0.8/1.0/1.5/2.0/2.5/3.0/4.0/5.0/6.0	/	Glossy	/	/
characteristic	1. Iron-gray luster, the surface is easy to scratch and rust, so you must pay attention to protection and quickly turn the order during processing. 2. Suitable for spray painting, baking paint, powder spraying... etc.
Stainless steel plate/SUS	0.8/1.0/1.5/2.0/2.5/3.0/4.0/5.0/6.0	/	Matte 2B / Brushed / Mirror	SUS201/SUS304/ SUS316	7.95KG/㎡
characteristic	1. The metallic white luster, the surface is not easy to rust, and can be divided according to the surface state: matte, shiny, mirror, brushed, etc. To protect the surface, PVC protective film is often attached. 2. Generally do not do surface treatment. Special surface treatment is required for baking varnish. 3. Can be sprayed and painted.
Aluminum plate/AL	1.0/1.2/1.5/2.0/2.5/3.0	110-136RmMPa 170~305RmMPa AL6061T6=27	Glossy / brushed	1060H24/3003/ 5052/6061	2.75KG/㎡
characteristic	1. The metallic white luster, the surface is easy to oxidize and corrode, so the surface is often pasted with PVC protective film. 2. Surface treatment: sandblasting, wire drawing, or polishing, anodizing (non-conductive, can be dyed in various colors); chromate oxidation (also known as conductive oxidation, there are two types of primary color and golden yellow)
Copper plate/CU	1.0/1.2/1.5/2.0/2.5/3.0	/	Glossy / brushed	H62	8.9KG/㎡
characteristic	1. H62 (that is, four or six brass), has good mechanical properties, good plasticity in hot state, plasticity in cold state, good machinability, easy brazing and welding, corrosion resistance, and various deep drawing The force-bearing parts manufactured by bending and bending are a widely used brass variety. 2. Surface treatment: Brush a layer of transparent paint on the brass surface to prevent outdoor atmospheric corrosion of brass. In addition, passivation treatment and electroplating treatment (copper plating, nickel plating, chrome plating) are often used.

Material Description

Cold Rolled Plate

The cold-rolled sheet has high hardness and relatively difficult processing, but it is not easy to deform and has high strength. With good cold bending and welding performance, and certain stamping performance. Through cold rolling, cold-rolled strip and steel plates with thinner thickness and higher precision can be obtained, with high straightness and surface finish High, clean and bright surface, easy to be coated and processed, multiple varieties, wide use, and at the same time has the characteristics of high stamping performance and low yield point.
Hot Rolled Plate

The hot-rolled sheet has relatively low strength and poor surface quality (oxidation\low finish), but good plasticity, generally medium-thick plate, cold-rolled sheet: high strength/high hardness, high surface finish, generally thin sheet, can be used for stamping Use the board. The mechanical properties are far inferior to cold working and inferior to forging, but it has better toughness and ductility.
Galvanized Sheet

Galvanized steel sheet is to prevent corrosion on the surface of the steel sheet and prolong its service life. The surface of the steel sheet is coated with a layer of metallic zinc. This kind of galvanized steel sheet is called galvanized sheet. It has a good appearance and must not have defects that are harmful to the use of the product, such as no plating, holes, cracks, scum, excessive plating thickness, scratches, Chromic acid fouling , white rust, etc.
Stainless Steel 201

Stainless steel 201 has the characteristics of polishing, no bubbles, and no pinholes. It is used to produce high-quality materials for various watch cases and strap back covers. It is mainly used for shallow stretched products and has the ability to resist general corrosion. Stainless steel 201 is mainly used for High temperature applications. High temperature applications require materials to have strong sensitization resistance to prevent inter-granular corrosion at lower temperatures.
Stainless Steel 304

It has good corrosion resistance, heat resistance, low temperature strength and mechanical properties; it has good hot work-ability such as stamping and bending, and no heat treatment hardening phenomenon (use temperature -196℃～800℃). It is resistant to corrosion in the atmosphere. If it is an industrial atmosphere or a heavily polluted area, it needs to be cleaned in time to avoid corrosion. It is suitable for food processing, storage and transportation. Has good processing properties and weld-ability. Stainless steel 304 is a nationally recognized food-grade stainless steel.
Stainless Steel 316

Corrosion resistance, atmospheric corrosion resistance and high temperature strength are particularly good, can be used under harsh conditions; excellent work hardening (non-magnetic); excellent high-temperature strength; non-magnetic in solid solution state; cold-rolled products have good gloss and beautiful appearance ; Relative to 304 stainless steel, the price is higher. The addition of Mo element to stainless steel 316 greatly improves its corrosion resistance and high temperature strength, and the high temperature resistance can reach 1200-1300 degrees.
Aluminum Plate 5052

Magnesium is the main alloying element in 5052 alloy aluminum plate, and it is the most widely used anti-rust aluminum. This alloy has high strength, especially fatigue resistance: high plasticity and corrosion resistance, and cannot be strengthened by heat treatment. The plasticity is good when hardened, and the plasticity is low when hardened by cold work. It has good corrosion resistance, good weldability, poor machinability, and can be polished.
Brass Plate H62

Ordinary brass with an average copper content of 62% has good mechanical properties, good plasticity in the hot state, plasticity in the cold state, good machinability, easy brazing and welding, corrosion resistance, but easy to cause corrosion cracking. In addition, the price is cheap, and it is a common brass variety that is widely used. It can be used to make all kinds of deep drawing and bending stress parts.

Laser Cutting & CNC Punch

Plate thickness supported by laser cutting

Notice of Laser Cutting

In sheet metal processing, laser cutting is often used for: blanking, cutting shape, secondary cutting, cutting line, cutting special-shaped holes, etc.Machining accuracy ±0.1mm

: When cutting the bottom hole of the hardware,it must be increased by 0.05mm, because there will be tiny contacts at the start and end of the cutting

: When cutting the craft hole, the width is generally greater than 0.5mm, the smaller the burr, the more obvious.

: In laser processing, the chamfer must be ≥0.5mmto prevent scorching.

CNC Punch

Common uses of CNC punching machines: blanking, punching mesh, punching convex hull, trimming, punching bumps, beading, crimping, punching, etc. Machining accuracy ±0.1mm
Hole extraction: The minimum distance between the NCT extraction hole and the edge is 3T, the minimum distance between two extraction holes is 6T (unless there is a special avoidance, which can be reduced), the minimum safety distance between the extraction hole and the bending edge (inside) is 3T+R, if it is too small, it must be crimped.
Generally, the height of NCT punch and half shear does not exceed 0.6T, if it is greater than 0.6T, it will easily fall off.
The distance between the hole and the edge should not be too small, the allowable value is shown in Table 1; the minimum hole diameter of NCT stamping is shown in Table 2: (T means material thickness)

Table 1: Material	Punching Round Hole	Punching Square Hole
Hard Steel	0.5T	0.4T
Mild Steel/Brass	0.35T	0.3T
Aluminum	0.3T	0.28T

Table 2: Material	Punching Round Hole	Punching Square Hole
Hard Steel	1.3T	1.0T
Mild Steel/Brass	1.0T	0.7T
Aluminum	0.8T	0.6T

Bending Process

Bending is the processing of changing the angle of the plate, such as bending the plate into a V shape , a U shape, and so on. In general, there are
two methods for bending sheet metal: One method is bending by die mould; The other is bending by bending machine. At present, JRPanel are
mainly processed by bending machines.

Common folding knife shapes & Common V groove shape

The minimum safety distance from the hole to the bending edge

The above dimensions are the distance from the hole to the inner bending edge. If it is less than this distance, bending will cause hole deformation. In this case, other processing methods can be used to solve the deformation problem:
①Bend first, then use laser to cut holes ②Pre-press line treatment ③Directly open mold production ④Eccentric bending ⑤Change to smaller V groove
However, most of this will increase the processing cost. When conditions permit, these minimum safety distances should be met as much as possible when designing.

Welding Process - Welder

It is a manufacturing process and technology for joining metals or other thermoplastic materials (such as plastic) by
heating, high temperature or high pressure.

Argon arc welding machine
Mainly for welding stainless steel, galvanized sheet, thin iron sheet, aluminum sheet
Carbon dioxide shielded welding
Mainly for some thick iron plates, and welding of large chassis
Inverter argon arc welding machine
Currently mainly for aluminum plate welding
Butt welding machine
Cold welded plate to plate seamless butt welding
Screw welding machine
Mainly for box body and flat plate welding stud

Common Surface Treatment

Surface treatment is a process of artificially forming a surface layer on the surface of the substrate material that is different from the
mechanical, physical and chemical properties of the substrate. Its purpose is to meet the product's corrosion resistance, wear
resistance, decoration or other special functional requirements.

Plating

Through chemical reaction, a layer of other metal is attached to the surface of the material to increase the corrosion resistance of the metal and achieve a certain beautification effect. It is a commonly used surface treatment method, such as: electrogalvanized, electroplated nickel, etc.
Spraying

By spraying, high-temperature baking, etc., a layer of paint of various colors is sprayed on the surface of the material to beautify the appearance and increase the anti-corrosion performance of the material. It is a common surface treatment method, generally liquid baking varnish and powder There are two types of paint, of which powder paint is the most common. The painted surface is non-conductive. Baking paint is not allowed in areas with EMC requirements.
Silkscreen Printing

The process of screen printing various logos on the surface of the material. Generally it includes flat screen printing and pad printing. The main principle is the same as the principle of camera film imaging, and it is also an exposure process. Flat screen printing is mainly used on general planes. But if you encounter a place with a deep pit, you need to use pad printing.
Brushed Surface

Place the material between the upper and lower rollers of the wire drawing machine. The rollers are attached with abrasive belts. Driven by the motor, the materials pass through the upper and lower abrasive belts to draw traces on the surface of the material. The thickness of the traces varies according to the abrasive belt. , The main function is to beautify the appearance. Generally, it is considered that the surface treatment method of drawing is used for aluminum.
Sandblasting

The sand particles are hit on the surface of the workpiece by the wind of the sandblasting machine, forming a dense pit on the surface of the workpiece. The main function is to remove the dirt on the surface of the workpiece, increase the adhesion of the workpiece surface, and prepare for the subsequent surface treatment. Not commonly used in our company.
Oxidation

The metal on the surface of the workpiece is oxidized to form a dense protective film on the surface of the workpiece to increase the corrosion resistance of the workpiece. Generally there are conductive oxidation and anodic oxidation, which is a common surface treatment method, such as anodic oxidation on the surface of radiator. (Can have different colors).