Steel EN19 · hardness band
Steel EN19-Z
Properties of the Z condition, compared with the other EN19 tempers.
Maximum-strength low-temper class for small highly stressed parts; low ductility and notch sensitivity.
What is EN19-Z?
EN19-Z is EN19 heat treated to Z — maximum-strength low-temper class for small highly stressed parts; low ductility and notch sensitivity. EN19-Z has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 95% of steel grades. Elongation at break is 7% and the elastic modulus is 205 GPa (29.7 Msi). EN19-Z has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F). HR is the default condition FabDigit quotes; Z is available on request or by drawing note.
Advantages
- High strength — 1,300 MPa (189 ksi), better than 95% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Limited ductility — 7%, worse than 96% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 87% of steel grades
EN19-Z properties
Typical room-temperature values for EN19-Z — 10 properties are specific to this condition; the rest are grade-level values shared by every EN19 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
EN19-Z has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,416°C (2,581 °F).
Mechanical16
EN19-Z has a yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 95% of steel grades. Elongation at break is 7% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
EN19-Z is rated for continuous service to 400°C (752 °F). It conducts heat at 42.6 W/m·K (24.6 BTU/hr·ft·°F), better than 50% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
EN19-Z conducts electricity at 7.8 % IACS, worse than 58% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of EN19-Z takes about 31 MJ of energy and emits 2.3 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 30%.
Manufacturability7
EN19-Z's machinability is fair (52/100, better than 52% of steel grades); weldability poor (15/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other EN19 tempers and conditions
EN19 is also supplied in 12 other conditions. The full side-by-side table is on the EN19 overview.
- HRDefaultCheapest stock form for parts that will be machined all over and then heat treated.520 MPa yield · 22 HRC
- ZMaximum-strength low-temper class for small highly stressed parts; low ductility and notch sensitivity.1,300 MPa yield · 48 HRC
- YVery high strength small-section parts; grinding usually replaces turning.1,130 MPa yield · 42 HRC
- XHigh-strength class for smaller sections; toughness starts to fall away.1,050 MPa yield · 40 HRC
- WFor highly loaded axles, connecting rods and studs in moderate sections.990 MPa yield · 36 HRC
- VHigher-strength shafting and high-tensile fasteners where toughness is still needed.900 MPa yield · 34 HRC
- Q&TStandard supplied condition for shafts and gear blanks — good strength/toughness balance and still machinable.830 MPa yield · 30 HRC
- UMost common EN19 supply class for general shafting and gear blanks.800 MPa yield · 31 HRC
- TLowest BS 970 tempered class — maximum toughness and easiest machining of the Q&T range.720 MPa yield · 28 HRC
- NormalizedUniform fine-grain structure for weld fabrications and parts not needing full Q&T strength.655 MPa yield · 31 HRC
- CDClose tolerance bright bar for shafts and studs machined without further heat treatment.635 MPa yield · 223 HB
- AnnealedPick for heavy machining, deep drilling or cold forming before final hardening.417 MPa yield · 197 HB
Working with EN19-Z
Is EN19 easy to machine?
Machine in the annealed or ≤32 HRC Q&T state with carbide at 100–160 m/min; above 40 HRC use CBN/ceramic or grind.
Can EN19 be welded?
Weldable with low-hydrogen consumables but requires 250–350 °C preheat, controlled interpass and immediate post-weld temper to avoid HAZ cracking.
Can EN19 be formed, bent or molded?
Hot forge 1100–1200 °C then normalise; cold bending only in the annealed condition with generous radii.
What surface finishes work on EN19?
No anodising — protect with zinc/manganese phosphate, black oxide, zinc or hard chrome plating, or nitride (up to ~600 HV) for wear surfaces.
EN19 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 |
|---|---|---|
| C | 0.36 – 0.44 | 0.4 |
| Si | 0.1 – 0.35 | 0.25 |
| Mn | 0.65 – 1 | 0.85 |
| Cr | 0.9 – 1.2 | 1.05 |
| Mo | 0.25 – 0.35 | 0.3 |
| P | ≤ 0.04 | 0.02 |
| Smax; 709M40 fine-machining variants allow 0.015–0.035 | ≤ 0.04 | 0.02 |
| Fe | balance | — |
EN19-Z — frequently asked
What is EN19-Z used for?
EN19-Z is typically used for drive shafts, crankshafts and industrial bolts. In short: workhorse Q&T English bar.
What is the yield strength of EN19-Z?
EN19-Z has a typical yield strength of 1,300 MPa (189 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 95% of steel grades. Strength varies by condition: see the 13 listed tempers.
Is EN19-Z easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). Machine in the annealed or ≤32 HRC Q&T state with carbide at 100–160 m/min; above 40 HRC use CBN/ceramic or grind.
Can EN19-Z be welded?
Not readily — weldability is rated poor (15/100). Weldable with low-hydrogen consumables but requires 250–350 °C preheat, controlled interpass and immediate post-weld temper to avoid HAZ cracking.
What surface finishes work on EN19-Z?
No anodising — protect with zinc/manganese phosphate, black oxide, zinc or hard chrome plating, or nitride (up to ~600 HV) for wear surfaces.
Can EN19-Z be formed, bent or molded?
Hot forge 1100–1200 °C then normalise; cold bending only in the annealed condition with generous radii.
What is the maximum service temperature of EN19-Z?
EN19-Z is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between EN19-HR and EN19-Z?
HR is the default condition — cheapest stock form for parts that will be machined all over and then heat treated. Z: maximum-strength low-temper class for small highly stressed parts; low ductility and notch sensitivity. Yield strength is 520 MPa in HR versus 1,300 MPa in Z.
Can FabDigit make parts in EN19-Z?
Yes — EN19-Z is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- BS 970-1: Wrought steels — 709M40 (EN19) — BSI (1991)
- EN 10083-3: Quenched and tempered steels — 42CrMo4 — CEN (2006)
- GB/T 3077 — 42CrMo — SAC (2015)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels — ASM International (1990)
- ASM Machining Data Handbook — ASM International (1980)
- Alloy steel 42CrMo4/4140 bar datasheet — Böhler / Ovako (2022)
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.