1075 C75 Spring Steel Coil
High carbon spring strip for flat springs blades circlips and stamped parts
Specifications
Spring Steel Coil
Spring Steel Coil and Strip in 1075 SK5 and SUP7
Alloy and carbon spring strip for springs clips blades and elastic components
Spring steel coil is alloy and carbon steel strip made specifically for springs, clips, retaining parts and other elastic components. It is bought by spring coilers, stamping shops and component makers in automotive, electrical and general industrial manufacturing who need the strip to return to shape after repeated deflection rather than take a set. The material is produced with controlled metallurgical quality, strict control of surface defects and decarburization, and tight shape and size, which is what keeps a progressive die running without breakage at the bend. Coil is released cold rolled, annealed or quenched and tempered, so a shop that heat treats in house and a shop that stamps finished parts can both order the condition that suits their process.
- Product Name — Spring steel coil and spring steel strip
- Place of Origin — China
- Standards — BS EN GB AISI ASTM DIN JIS
- Material — 1075 CK75 1.1248 SK4 SK5 SK65 9260 SUP6 SUP7 6150 60Si7 60C2 56Si7 1.5026
- Grade — 1075 CK75 1.1248 SK4 SK5 SK65 9260 SUP6 SUP7 6150 60Si7 60C2 56Si7 1.5026
Why It Is Specified
Key Benefits of Spring Steel Coil
Returns to Shape After Deflection
The strip withstands a large amount of deformation without breaking and has strong resilience and recovery, so a part compressed bent or stretched springs back instead of taking a permanent set.
Delivery Condition Matched to Your Process
Cold rolled, annealed and quenched and tempered conditions are available, so you can stamp in the soft condition and heat treat afterwards or buy strip already at working hardness.
Surface Defects and Decarburization Controlled
Surface defects and decarburization are strictly controlled, which matters because a decarburized skin is where a spring cracks first under cyclic load.
Holds Properties Under High Frequency Duty
Spring steel keeps stable mechanical properties under long term high frequency working conditions and is less prone to plastic deformation and fatigue fracture.
Carbon and Alloy Grades From One List
1075 CK75 SK4 SK5 SK65 9260 SUP6 SUP7 6150 60Si7 60C2 56Si7 and 1.5026 are held together, so a drawing written to JIS DIN or AISI can be filled without substitution.
Thin Gauge for Progressive Dies
Thickness from 0.1mm to 10mm covers thin strip for contact springs and clips through to heavier sections for leaf and industrial springs.
Problems It Solves
What This Material Removes From Your Process
Parts Taking a Set Instead of Springing Back
Ordinary carbon strip deforms permanently under repeated deflection. Spring steel withstands large deformation without breaking and recovers its original state, which is what the component was designed to do.
Cracking That Starts at a Decarburized Skin
A decarburized surface fails early under cyclic stress. Surface defects and decarburization are strictly controlled on this material so the skin is not the weak point.
Buying the Wrong Delivery Condition
Strip that arrives hardened cannot be stamped and strip that arrives soft has to be heat treated. Cold rolled, annealed and quenched and tempered conditions are quoted separately so the order matches the process.
Grade Substitution Across Standards
A drawing calling SK5 or SUP7 is often filled with a nearest equivalent. Holding the JIS DIN AISI and GB grades together means the named grade can be supplied and documented.
Shape Variation Stopping a Die
Camber and thickness variation cause feed problems and broken tooling on progressive dies. The material is produced to precise shape and size for that reason.
Application Scenarios
Where It Is Used
Automotive Springs and Clips
Leaf sections, retaining clips, seat and latch springs and other formed parts on automotive assembly lines.
Electrical and Electronic Contacts
Contact springs, battery terminals, connector clips and shield fingers stamped from thin gauge strip in electrical and electronic manufacturing.
Industrial Machinery Elastic Components
Tension and compression elements, wipers, doctor blades and retaining rings in industrial equipment where a part must recover its shape every cycle.
Hand Tool and Blade Production
Saw blade backs, scrapers, measuring tapes and other parts where the carbon grades are hardened after forming.
Stamped Fastener and Retainer Parts
Spring washers, circlips, spring nuts and panel fasteners run on progressive dies from annealed or cold rolled strip.
Agricultural and Construction Equipment Tines
Tines, fingers and flexing components on machines where the part is deflected repeatedly by ground or material contact.
Who It Is For
Buyers Who Specify This Product
- Spring manufacturers buying strip in a stated condition for coiling and forming lines
- Stamping and press shops buying annealed strip for progressive die work that is heat treated afterwards
- Automotive component suppliers buying SUP and 60Si grade strip against a customer drawing
- Electrical and electronics manufacturers buying thin gauge strip for contact and clip parts
- Tool and blade makers buying carbon grades such as SK4 SK5 and 1075 for hardening after forming
- Distributors supplying spring strip to regional spring coilers and fabricators
Technical Data
Specifications and Technical Features
Values below come from the product data published by Shandong Tianyu Metal Products. Confirm the exact grade and size against your order.
| Product Name | Spring steel coil and spring steel strip |
|---|---|
| Place of Origin | China |
| Standards | BS EN GB AISI ASTM DIN JIS |
| Material | 1075 CK75 1.1248 SK4 SK5 SK65 9260 SUP6 SUP7 6150 60Si7 60C2 56Si7 1.5026 |
| Grade | 1075 CK75 1.1248 SK4 SK5 SK65 9260 SUP6 SUP7 6150 60Si7 60C2 56Si7 1.5026 |
| Thickness | 0-10mm with the 0.1mm-10mm range or customized as required |
| Width | Customized as required |
| Size | Customized size |
| Technique | Cold rolled annealed quenched and tempered |
| Application | Automotive manufacturing electronic and electrical manufacturing industrial manufacturing |
| Processing Service | Bending welding decoiling cutting punching |
| Surface | Nature or painted |
| Certificate | Mill test certificate |
| Sample | Available |
Technical Features
- Grades 1075 CK75 1.1248 SK4 SK5 SK65 9260 SUP6 SUP7 6150 60Si7 60C2 56Si7 and 1.5026
- Thickness 0.1mm to 10mm or customized as required
- Delivery condition cold rolled annealed or quenched and tempered
- Produced to BS EN GB AISI ASTM DIN and JIS standards
- Strict control of surface defects and decarburization
- Precise shape and size with high purity and uniform metallurgical structure
- Surface supplied natural or painted
- Processing covers bending welding decoiling cutting and punching
Materials
- Carbon spring steel grades including 1075 CK75 SK4 SK5 and SK65
- Silicon manganese spring alloy grades including 9260 60Si7 60C2 and 56Si7
- Chromium alloy spring grades including SUP6 SUP7 and 6150
- European numbered equivalents 1.1248 and 1.5026
Certification
- Mill test certificate supplied with the coil
Manufacturing
How It Is Made and Processed
Melting and alloying to the ordered spring steel grade
Hot rolling to intermediate strip thickness
Cold rolling to the ordered gauge from 0.1mm to 10mm
Annealing where the strip is to be supplied soft for stamping
Quenching and tempering where the strip is to arrive at working hardness
Surface control for defects and decarburization
decoiling and decoiling to the ordered strip width
Coil banding and export packing
Quality Control
Checks Before It Ships
- Grade chemistry confirmed against the ordered designation
- Thickness checked across the ordered 0.1mm to 10mm range
- Surface inspected for defects and decarburization before release
- Shape and width verified against the ordered strip size
- Delivery condition confirmed as cold rolled annealed or quenched and tempered
- Mill test certificate issued for the supplied coil
Customization
What We Can Change on Your Order
- Grade chosen from the carbon silicon manganese and chromium alloy ranges
- Thickness set anywhere from 0.1mm to 10mm
- Strip width slit to your die or coiler feed
- Delivery condition ordered as cold rolled annealed or quenched and tempered
- Natural or painted surface on release
- Cutting punching and bending carried out before shipment
Comparison
Spring Steel Coil Against the Alternatives
| Ordinary carbon steel strip | Carbon strip takes a permanent set under repeated deflection, where spring steel withstands large deformation without breaking and returns to its original state. |
|---|---|
| Stainless steel spring strip | Spring steel is chosen where fatigue performance and cost matter more than corrosion resistance, and the finished part is usually plated or oiled instead. |
| Spring wire | Strip suits flat stamped and formed parts such as clips washers and blades, where wire suits coiled helical springs. |
| Buying hardened strip for stamping | Annealed strip stamps cleanly and is hardened afterwards, which extends tool life compared with pressing already hardened material. |
Use Guide
Specifying Handling and Welding Notes
- Order annealed strip where the part is formed on a progressive die and heat treated after stamping
- Order quenched and tempered strip where the shop has no heat treatment and the part is formed at working hardness
- Bend across the rolling direction where the design allows because a bend along the grain cracks more easily
- Allow for springback when setting form tools and prove the bend radius on the ordered grade before running production
- Keep coils oiled and dry in storage because surface rust on spring strip becomes a fatigue starting point
- Ask for the mill test certificate so the grade and delivery condition are documented for the customer drawing
Questions Buyers Ask
Spring Steel Coil FAQ
Which spring steel grades can you supply?
1075 CK75 1.1248 SK4 SK5 SK65 9260 SUP6 SUP7 6150 60Si7 60C2 56Si7 and 1.5026. Quote the grade from your drawing and it is supplied against the standard it belongs to.
What thickness range is available?
From 0.1mm to 10mm, or customized as required. Thin gauge suits contact springs and clips, heavier gauge suits leaf and industrial spring parts.
Can I get the strip soft for stamping?
Yes. Coil is supplied cold rolled, annealed or quenched and tempered. Annealed strip stamps cleanly and is hardened after forming, which is easier on tooling.
How do you control decarburization?
Surface defects and decarburization are strictly controlled during production, because a decarburized skin is where a spring normally starts to crack under cyclic load.
Can you slit the coil to our strip width?
Yes. Decoiling and cutting are part of the processing service, so the coil arrives at the width your die or coiler feed takes.
Do you supply a mill test certificate?
A mill test certificate is issued for the supplied coil covering the grade. Ask for the mill test certificate when you place the order so it ships with the material.
Is a sample available before we commit to a production coil?
Samples are available. Send the grade, thickness and delivery condition you want to test and we will confirm what can be released.
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