Understand how different materials behave during press brake bending. Learn about springback, cracking, force requirements, and best practices for each material type.
Introduction
Different materials behave differently during bending due to variations in yield strength, elastic modulus, ductility, and work-hardening. At Fulei Metal, we bend all common sheet metals and optimize parameters for each.
Material Properties That Affect Bending
Yield Strength
Mild steel: 170-250 MPa. High-strength steel: 345+ MPa. Stainless steel: 205-310 MPa. Aluminum 5052: 130-200 MPa. Aluminum 6061-T6: 240-276 MPa. Higher yield strength means more springback.
Elastic Modulus
Steel: 210 GPa. Stainless: 193 GPa. Aluminum: 70 GPa. Lower modulus means more elastic recovery despite lower yield strength.
Ductility and Elongation
Mild steel: 20-25%. Stainless: 40-60%. Aluminum 5052: 12-18%. Higher elongation allows tighter radii.
Work Hardening
Stainless steel work-hardens significantly (30-50% hardness increase). Aluminum work-hardens moderately. Mild steel minimally.
Mild Steel Bending
Easiest to bend. Springback 1-3 degrees. Minimum radius 0.8-1.0 times thickness. Low cracking risk. Standard V-die openings work well.
Stainless Steel Bending
More challenging. Springback 2-5 degrees. Minimum radius 1.0-1.5 times thickness. 30-50% more force than mild steel. Use wider die openings and real-time angle measurement. Avoid re-bending due to work hardening.
Aluminum Bending
Moderate springback 1-4 degrees varying by alloy. Minimum radius 1.0-2.0 times thickness. About 1/3 the force of steel. Soft alloys crack-resistant, hard alloys prone to cracking. Use polished tools and protective film.
Galvanized Steel Bending
Similar to mild steel. Springback 1-3 degrees. Use slightly larger radii to prevent coating cracking. Clean tools regularly for zinc residue.
Conclusion
Different materials require different approaches. Understanding how properties affect bending enables selecting appropriate parameters. At Fulei Metal, our experience ensures the right parameters for each material.
Material Comparison for Bending Decisions
The same flange behaves differently in four common materials, and a drawing drawn for one is rarely optimal for another. Values below are typical room-temperature properties used for estimating; we confirm against the mill certificate on the batch we actually form.
| Material | Yield / tensile strength (typical) | Min. bend radius | Behaviour that affects forming |
|---|---|---|---|
| SPCC (DC01) mild steel | about 210 / 340 MPa | 0.5 to 1 × t | the forgiving baseline for most designs |
| SECC galvanized steel | about 220 / 340 MPa | 1 × t | the zinc layer can flake at very small radii |
| SUS304 stainless | about 215 / 520 MPa | 1 × t | high springback, work hardens during forming |
| SUS430 ferritic stainless | about 280 / 480 MPa | 1.5 to 2 × t | less ductile than 304, watch the grain |
| Aluminium 5052-H32 | about 195 / 230 MPa | 1 × t | good formability, common for outdoor parts |
| Aluminium 6061-T6 | about 275 / 310 MPa | 2 to 3 × t | cracks easily; see below before specifying |
Two practical notes follow from that table. First, the material that looks strongest on paper is often the worst choice for a tight bend: 6061-T6 has modest strength but poor bend ductility, so if a drawing calls for it with a 1 × t radius, that combination should be questioned before quoting. Second, when a part will be powder coated, choose the substrate for corrosion and formability — the coating comes after forming and does not rescue a cracked bend.
Frequently Asked Questions
Which material gives the least springback?
Mild steel, by a wide margin. Stainless roughly doubles it and aluminium sits in between, although aluminium tempers vary much more than steel grades do.
Does the coating come before or after bending?
Powder coating is applied after forming and welding, so it does not affect bending. Pre-painted or pre-coated sheet is different — the coating is already on the surface and has its own bend rating.
Can you source a material we specify by European or Japanese standard?
We normally work to JIS and GB equivalents and cross-reference to EN or ASTM grades with you at quoting. What matters is agreeing the standard before ordering, not after the first batch.
Questions about a specific part are usually faster to answer against the drawing — send it through the review route below.
About these figures. The reference values above come from our own production range; aluminium alloy and temper choice lists the machines and materials behind them, and full service overview explains the adjacent steps that change the formed result. For your own part, materials and thickness range is the fastest route to a quote — the earlier we see the drawing, the more of it can still be adjusted without cost. The tolerance context is set out in stainless grade-specific behaviour.