Steel E155 +U (Hot rolled)
Finish state
EN E155
Cheapest stock condition for non-critical bar, tube and sections where only the minimum yield of 155 MPa must be met.
Values for the +U condition
Other E155 tempers and conditions
E155 is listed in 6 conditions; see the grade overview at E155.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ADefault Annealed | Softest condition — pick for maximum cold forming, deep drawing, bending and cold heading of bar, wire and precision tube. | 180 | 300 | 35 | 95 HB | — |
Normalized | Pick when a uniform fine-grained structure and reproducible strength/toughness are required after hot forming or welding. | 200 | 320 | 32 | 105 HB | — |
+UThis page Hot rolled | Cheapest stock condition for non-critical bar, tube and sections where only the minimum yield of 155 MPa must be met. | 200 | 340 | 30 | 105 HB | — |
Cold drawn, soft | Precision-drawn dimensions with retained ductility — for tube that still has to be bent, flared or expanded. | 220 | 340 | 28 | 110 HB | — |
Stress relieved | Cold-drawn strength with residual stresses removed — for straight, dimensionally stable tubes and shafts that will be machined. | 280 | 390 | 18 | 125 HB | — |
Cold drawn | Pick for close-tolerance precision tube and bright bar where higher strength, straightness and a smooth bore/surface are needed and no further forming follows. | 340 | 430 | 10 | 135 HB | — |
What is E155 +U?
E155 +U is E155 supplied in the +U condition — cheapest stock condition for non-critical bar, tube and sections where only the minimum yield of 155 MPa must be met. E155 +U has a yield strength of 200 MPa (29 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 98% of steel grades. Elongation at break is 30% and the elastic modulus is 210 GPa (30.5 Msi). E155 +U has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,495°C (2,723 °F). +A is the default condition FabDigit quotes; +U is available on request or by drawing note.
Advantages
- Conducts heat well — 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades
- Readily welded — 95/100, better than 97% of steel grades
- Forms and bends easily — 85/100, better than 96% of steel grades
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Ductile — tolerates forming and impact — 30%, better than 93% of steel grades
Limitations
- Low strength — 200 MPa (29 ksi), worse than 98% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
E155 +U properties
Typical room-temperature values for E155 +U; 14 are specific to this condition. Other listed values are E155 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
E155 +U has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,495°C (2,723 °F).
Mechanical16
E155 +U has a yield strength of 200 MPa (29 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 98% of steel grades. Elongation at break is 30% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
E155 +U is rated for continuous service to 350°C (662 °F). It conducts heat at 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
E155 +U conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of E155 +U takes about 24 MJ of energy and emits 1.9 kg of CO₂ — less than 97% of steel grades. Typical recycled content is 30%.
Manufacturability6
E155 +U's machinability is fair (52/100, better than 52% of steel grades); weldability excellent (95/100); formability excellent (85/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with E155 +U
Is E155 easy to machine?
Soft and gummy — use sharp positive-rake tools, high speed, generous coolant and chip breakers; cold-drawn (+C/+SR) condition machines noticeably cleaner than annealed.
Can E155 be welded?
Excellent weldability by all arc, resistance and gas processes with CEV ≈ 0.15; no preheat or PWHT needed in normal sections.
Can E155 be formed, bent or molded?
Outstanding cold formability in +A/+LC — deep drawing, cold heading, tube bending and flaring; hot forming 850–1100 °C followed by +N.
What surface finishes work on E155?
Rusts quickly, so zinc plate, phosphate, black-oxide plus oil, galvanize or paint; case carburizing/nitrocarburizing gives a hard wear surface on the soft core.
E155 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cvery low carbon — cold heading / deep drawing grade | ≤ 0.1 | 0.07 |
| Sitypical mill practice; often not limited for this grade | ≤ 0.35 | 0.15 |
| Mn | ≤ 0.45 | 0.35 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.02 |
| Fe | balance | — |
E155 +U — frequently asked
What is E155 +U used for?
E155 +U is typically used for cold-formed brackets, low-stress pins and shafts, general fasteners, wire products and light-duty machine parts. In short: best-forming carbon steel; weldable without preheat; low strength, low cost.
What is the yield strength of E155 +U?
E155 +U has a typical yield strength of 200 MPa (29 ksi) and a tensile strength of 340 MPa (49.3 ksi) — weaker than 98% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is E155 +U easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Soft and gummy — use sharp positive-rake tools, high speed, generous coolant and chip breakers; cold-drawn (+C/+SR) condition machines noticeably cleaner than annealed.
Can E155 +U be welded?
Yes — weldability is rated excellent (95/100). Excellent weldability by all arc, resistance and gas processes with CEV ≈ 0.15; no preheat or PWHT needed in normal sections.
What surface finishes work on E155 +U?
Rusts quickly, so zinc plate, phosphate, black-oxide plus oil, galvanize or paint; case carburizing/nitrocarburizing gives a hard wear surface on the soft core.
Can E155 +U be formed, bent or molded?
Outstanding cold formability in +A/+LC — deep drawing, cold heading, tube bending and flaring; hot forming 850–1100 °C followed by +N.
What is the maximum service temperature of E155 +U?
E155 +U is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10305-1 Steel tubes for precision applications — seamless cold drawn tubes — CEN (2016)
- EN 10027-2 Designation systems for steels — Numerical system (1.0033) — CEN (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Machinery's Handbook (machinability ratings) — Industrial Press (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.