Steel 16MnCr5 · heat-treated state
Steel 16MnCr5 +AC
Properties of the +AC condition, compared with the other 16MnCr5 tempers.
Sub-critical/spheroidize anneal giving globular carbides in ferrite for maximum cold-formability and easy shear cutting before carburizing.
What is 16MnCr5 +AC?
16MnCr5 +AC is 16MnCr5 heat treated to +AC — sub-critical/spheroidize anneal giving globular carbides in ferrite for maximum cold-formability and easy shear cutting before carburizing. 16MnCr5 +AC has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 84% of steel grades. Elongation at break is 24% and the elastic modulus is 210 GPa (30.5 Msi). 16MnCr5 +AC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; +AC is available on request or by drawing note.
Advantages
- Forms and bends easily — 78/100, better than 91% of steel grades
Limitations
- Low strength — 305 MPa (44.2 ksi), worse than 84% of steel grades
16MnCr5 +AC properties
Typical room-temperature values for 16MnCr5 +AC — 37 properties are specific to this condition; the rest are grade-level values shared by every 16MnCr5 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical3
16MnCr5 +AC has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical14
16MnCr5 +AC has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 84% of steel grades. Elongation at break is 24% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
16MnCr5 +AC is rated for continuous service to 400°C (752 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
16MnCr5 +AC 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 16MnCr5 +AC takes about 29 MJ of energy and emits 2.1 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 30%.
Manufacturability7
16MnCr5 +AC's machinability is good (58/100, better than 75% of steel grades); weldability good (60/100); formability very good (78/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 16MnCr5 tempers and conditions
16MnCr5 is also supplied in 10 other conditions. The full side-by-side table is on the 16MnCr5 overview.
- HRDefaultStandard stock condition for gear blanks and machined parts that will be carburized after roughing.400 MPa yield · 180 HB
- Q&TRepresents the through-hardened core state of small sections (≤30 mm) after 860–900 °C oil quench and 150–200 °C temper.700 MPa yield · 31 HRC
- CHThe service condition for gears and splines: hard wear-resistant 0.2–1.5 mm case over a tough core.700 MPa yield · 61 HRC
- CDUse for automatic-lathe production of small shafts and pins where close tolerance and good surface finish are needed before carburizing.560 MPa yield · 215 HB
- +AC+CSpheroidize-annealed then cold drawn to size: higher strength and better surface/tolerance than +AC, with reduced ductility from the drawing strain.500 MPa yield · 185 HB
- AnnealedPick for cold forging, deep drawing or heavy cold extrusion of blanks; lowest hardness and best cold formability.320 MPa yield · 165 HB
- +ACSub-critical/spheroidize anneal giving globular carbides in ferrite for maximum cold-formability and easy shear cutting before carburizing.305 MPa yield · 150 HB
Working with 16MnCr5 +AC
Is 16MnCr5 easy to machine?
Machines well in +A/+FP/+TH condition (~55–65 % of 1212); finish-grind after carburizing since the 58–64 HRC case is essentially unmachinable.
Can 16MnCr5 be welded?
Weld only in the soft/normalized state with low-hydrogen consumables, preheat 150–250 °C and post-weld stress relief; never weld carburized surfaces.
Can 16MnCr5 be formed, bent or molded?
Good cold forgeability and heading after spheroidize annealing; hot forge 1100–850 °C followed by controlled cooling or normalizing.
What surface finishes work on 16MnCr5?
No anodizing — use phosphating plus oil, black oxide, zinc or nickel plating; shot peening of tooth roots markedly raises bending fatigue life.
16MnCr5 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 | 0.14 – 0.19 | 0.16 |
| Simax per EN 10084 | ≤ 0.4 | 0.25 |
| Mn | 1 – 1.3 | 1.15 |
| Cr | 0.8 – 1.1 | 0.95 |
| P | ≤ 0.03 | — |
| Smax; 16MnCrS5 variant is 0.020–0.040 | ≤ 0.04 | — |
| Fe | balance | — |
16MnCr5 +AC — frequently asked
What is 16MnCr5 +AC used for?
16MnCr5 +AC is typically used for gears, industrial drive shafts and pins. In short: carburizing Cr-Mn bar.
What is the yield strength of 16MnCr5 +AC?
16MnCr5 +AC has a typical yield strength of 305 MPa (44.2 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 84% of steel grades. Strength varies by condition: see the 11 listed tempers.
Is 16MnCr5 +AC easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machines well in +A/+FP/+TH condition (~55–65 % of 1212); finish-grind after carburizing since the 58–64 HRC case is essentially unmachinable.
Can 16MnCr5 +AC be welded?
Yes — weldability is rated good (60/100). Weld only in the soft/normalized state with low-hydrogen consumables, preheat 150–250 °C and post-weld stress relief; never weld carburized surfaces.
What surface finishes work on 16MnCr5 +AC?
No anodizing — use phosphating plus oil, black oxide, zinc or nickel plating; shot peening of tooth roots markedly raises bending fatigue life.
Can 16MnCr5 +AC be formed, bent or molded?
Good cold forgeability and heading after spheroidize annealing; hot forge 1100–850 °C followed by controlled cooling or normalizing.
What is the maximum service temperature of 16MnCr5 +AC?
16MnCr5 +AC 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 16MnCr5-HR and 16MnCr5-CH?
HR is the default condition — standard stock condition for gear blanks and machined parts that will be carburized after roughing. CH: the service condition for gears and splines: hard wear-resistant 0.2–1.5 mm case over a tough core. Yield strength is 400 MPa in HR versus 700 MPa in CH.
Can FabDigit make parts in 16MnCr5 +AC?
Yes — 16MnCr5 +AC 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
- EN 10084 — Case hardening steels, technical delivery conditions — CEN (2008)
- EN 10084 / DIN 17210 grade 1.7131 (16MnCr5) — DIN (1998)
- SAE J404 — Chemical compositions of SAE alloy steels (5115) — SAE International (2009)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 4A — Steel Heat Treating Fundamentals and Processes — ASM International (2013)
- Dörrenberg Edelstahl / Ovako 1.7131 (16MnCr5) data sheet — Dörrenberg / Ovako (2021)
- Machinery's Handbook, 31st ed. — 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.