Spring Steel Sheet: Grades, Manufacturing Methods, CNC Machining & Applications

As you know, automotive and industrial suspension are the common uses of spring steel. These steels have very high yield strength which helps them to return to their original shape. Spring steel sheet metal is a sheet or plate form of spring steel and used to manufacturing mechanical components. This article will give you deep insight into spring steel sheet.

What Is Spring Steel Sheet?

Spring steel sheet is a specialized and flat-rolled steel alloy. It is designed for high yield strength and extreme elasticity. Spring steel sheet has ability to return to its original shape after significant bending, twisting, or deformation.

Spring Steel Sheet Vs Spring Steel Strip

Sheet and strip are simply two different forms of spring steel. Sheet is supplied as flat, relatively wide material, while strip is narrower and often supplied in long lengths or coils. These forms are used to suit different part geometries and improve manufacturing efficiency. Spring steel sheet is generally better suited to wider parts, whereas strip is more practical for narrow or elongated components. Because the part shapes and material formats are different, the manufacturing processes used for sheet and strip can also vary.

Advantages of Spring Steel Sheet

Spring steel sheet metal when transformed into sheets and plates provides a unique balance of properties like strength, formability and other characteristics that are perfect for constant and repetitive motion without failure.

Excellent Elasticity

Elasticity is needed when repeated deformation occurs and returns to its original shape. High elastic limit can handle high loading stress without permanent deformation. Spring steel plates and sheet can survive millions of loadings and unloading cycles.

Excellent Machinability

Spring steel plates are hard but is remarkably machinable and provide formability. Flat spring material can easily be cut, stamped, or formed into complex or intricate geometry for custom machining.

Good Accuracy Control

Spring steel plates and sheets are manufactured to offer high dimensional accuracy. This feature is ideal for high precision cutting because they have dimensional stability under high loads and elevated temperatures.

Manufacturing Methods for Your Spring Steel Sheet Parts

There are diverse manufacturing methods for machining spring steel sheet parts for different shapes and features. Below provides the common processes for spring steel sheet.

Laser Cutting

Laser cutting is a good choice for flat parts that mainly contain two-dimensional features, such as through holes, notches, outer profiles, or complex curved contours.

Stamping

Stamping is often the best choice when spring steel parts require features such as embosses, small holes, slots, lances, flanges, or through holes, especially when the same design needs to be produced repeatedly in high volumes.

Bending

Bending is the preferred process when spring steel parts require three-dimensional features such as flanges, tabs, U-shaped bends, V-bends, hooks, or Z-bends. It forms flat spring steel sheet into the required 3D geometry without removing material.

Wire EDM

Wire EDM is a suitable choice when spring steel sheet parts require very narrow through-slots, small internal radii, sharp internal corners, or high-precision holes that are difficult to achieve with conventional cutting methods.

CNC Machining

CNC machining is particularly suitable for complex spring steel sheet parts that require features such as blind holes, counterbores, countersinks, stepped surfaces, precision holes, chamfers, radii, and threads. It provides precise control over dimensions, feature depth, and geometry, and critical features can typically be machined to tolerances as tight as ±0.0005.

After leaning these machining processes, you can easily select the suitable method for your spring steel sheet parts.

Challenge for CNC Machining Spring Steel Sheet

As we know, spring sheet metal has high strength and elasticity, but it also has challenges during CNC machining.

Tool wear

Spring steel sheet material has high hardness which makes it highly abrasive to cutting tools. this causes carbide tools to wear down faster than machining other steels. Lower cutting speeds, higher feed rates, and very sharp tools can minimize tool wear.

Thermal distortion

Hardened and tempered spring steel sheets generate more heat during machining. This causes local overheating and if any change occurs to temper of the steel, leading to soft spots. Proper cooling can dissipate heat and prevent thermal deformation.

Difficult clamping of thin sheets

Spring sheet metal is often thin and is susceptible to vibration and bending during milling. This leads to poor surface finish and dimensional errors. Use of standard vice clamps can warp the sheet.

Typical Grades of Spring Steel Steel

Spring steel is a specialized category of low-alloy manganese. These are medium-carbon or high-carbon steel, characterized by very high yield strength. Some materials like music wire (ASTM A228) are used for coiled springs and alloy steels (55Cr3) are frequently used for precision parts, flat springs, and washers produced by CNC milling. You can find details about the compositions and properties of these spring steel in the following content.

AISI 1074 /1075 Spring Steel

These are high-carbon steels and are commonly referred to as "blue tempered" or "scaleless" spring steel. They have excellent elasticity, toughness, and fatigue resistance. AISI 1074 and 1075 spring steels are ideal for precision flat springs, clips, washers, and wear strips.

55Cr3 Steel

55Cr3 is chromium-alloyed spring steel. It is widely used in Europe and internationally for heavy-duty applications. This spring steel has higher hardenability and fatigue resistance than non-alloyed carbon steel.

17-7ph Stainless Steel

17-7PH is a precipitation-hardening stainless steel. It has high strength of carbon spring steel combined with the corrosion resistance of 18-8 stainless steel. It can retain high elasticity at higher temperatures. This spring steel is best used in aerospace, medical instruments, and precision electronic connectors.

What Is Spring Steel Sheet Used for?

Spring sheet metal is processed to make parts that have ability to withstand repetitive stress without permanently deformation. These are parts are used in high-stress applications and are explained as:

Spring Washer

Spring washers can maintain tension in bolted joints. These are designed to prevent loosening due to vibration or thermal expansion. Spring washers are used in automotive, aerospace and electrical or electronics industries.

Spring Clips

Spring clips include Terry clips, S-clips, and U-clips. These are flexible fasteners that secure, clamp, or hold objects together using tension. Spring clips have quick assembly and high-vibration resistance. These are used in automotive, electronics and manufacturing industries.

Spring Retainer Plates

Spring retainer plates are flat or shaped spring steel. They can hold other parts like bearings or springs) in place with managing axial load. Spring retainer plates are used in machinery and industries and for automotive transmission.

Scraper Blade

Scraper blades made from spring steel sheet metal have high abrasion resistance and flexibility. They can clean surfaces without scratching or breaking. Scraper blades are used in industrial machinery, agriculture, construction and in consumer goods.

Conclusion

CNC machining of spring steel sheet metal creates parts with high precision for like vehicles (suspension) and machinery. These complex designs with CNC provide accuracy and automation in both forms, from small springs to large chassis. Tuofa professional CNC service provides precision and complex shapes with applications covering automotive, aerospace, appliances, and construction.

FAQ

How to make spring steel sheets?

Spring steel sheet are formed from hot rolling into strips or sheets. These are then heat treated, quenching in oil or water or tempered to attain high strength, resilience, and flexibility, often after cold working.

Can you stamp spring steel?

Yes, you can stamp spring steel. It is mostly done for making flexible and durable parts like clips, fasteners, and actual springs.

Is 4140 a spring steel?

Yes, 4140 is a type of alloy steel and used for making high-performance springs. These are used in automotive and industrial applications.

What is spring back effect in sheet metal?

Springback in spring steel sheet metal is the ability in material to partially return to its original shape after bending forces are removed. This is caused by its inherent elasticity.