Steel 20MnTiB
GB 20MnTiB
20MnTiB is a manganese-titanium-boron carburizing steel (GB/T 3077) in which titanium refines grain and boron raises hardenability at low alloy cost.
Reference datasheet — 20MnTiB is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the A condition
20MnTiB tempers and conditions
20MnTiB is supplied in 7 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard delivery condition for gear-blank bar: soft, uniform structure for hobbing and shaping before carburizing. | 380 | 620 | 22 | 170 HB | — |
Hot rolled | Mill as-rolled bar; hardness scatter is high, normally re-annealed or normalized before machining. | 430 | 700 | 18 | 14 HRC | 8 % IACS |
Normalized | Choose to homogenize forgings and refine grain before carburizing when distortion control matters. | 450 | 700 | 19 | 14 HRC | 8 % IACS |
Cold drawn | Pick for close-tolerance bright bar used on automatics; strength up, ductility down versus annealed. | 620 | 750 | 11 | 18 HRC | 8 % IACS |
oil quenched + tempered ≈450 °C (medium-hardness through-hardened) | Use where toughness and machinability matter more than peak strength, e.g. shafts and links that are not carburized. | 780 | 950 | 15 | 30 HRC | — |
Carburized and hardened | The production condition for gears: 0.6–1.4 mm hardened case at 58–62 HRC over a 30–40 HRC tough core. | 950 | 1,200 | 10 | 60 HRC | — |
oil quenched 860 °C + tempered 200 °C (GB/T 3077 test condition) | The specification heat treatment used for acceptance testing; also used for through-hardened high-strength shafts and fasteners. | 980 | 1,180 | 12 | 38 HRC | — |
What is 20MnTiB?
20MnTiB is a manganese-titanium-boron carburizing steel (GB/T 3077) in which titanium refines grain and boron raises hardenability at low alloy cost. It is used for carburized truck and tractor gears and shafts, and is supplied hot rolled, annealed, normalized, cold drawn or cold headed. The annealed default condition gives 380 MPa yield, 620 MPa tensile, 22 % elongation and 170 HB (87 HRB), with service to about 350 °C. Carbon equivalent near 0.6 makes weldability poor to fair and there is no bare corrosion resistance; 20CrMnTiB is the choice when a deeper case and higher core strength are needed. 20MnTiB 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). 20MnTiB has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 68% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
What is 20MnTiB used for?
- truck gears
- tractor gears
- carburized shafts
20MnTiB properties
Typical room-temperature values for 20MnTiB-A; bars are the position among steel grades.
Physical3
20MnTiB 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).
Mechanical13
20MnTiB has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 68% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
20MnTiB is rated for continuous service to 350°C (662 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
20MnTiB conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 20MnTiB takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
20MnTiB's machinability is good (55/100, better than 62% of steel grades); weldability fair (40/100); formability good (55/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 20MnTiB is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 20MnTiB
Is 20MnTiB easy to machine?
Machine in the annealed (≤187 HB) or normalized state with coated carbide; sticky low-carbon chips need positive rake and good coolant — machinability roughly 55–60 % of 1212.
Can 20MnTiB be welded?
Poor to fair: carbon equivalent ~0.6 with boron, so use low-hydrogen consumables, 150–250 °C preheat and immediate stress relief; never weld after carburizing.
Can 20MnTiB be formed, bent or molded?
Hot forge 1150–850 °C then normalize/anneal; cold heading and moderate cold forming are practical only in the spheroidize-annealed condition.
20MnTiB 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 | 0.17 – 0.24 | 0.2 |
| Si | 0.17 – 0.37 | 0.27 |
| Mnmain hardenability element | 1.3 – 1.6 | 1.45 |
| Tifixes N, refines austenite grain, protects boron | 0.04 – 0.1 | 0.07 |
| Bhardenability booster | 5×10⁻⁴ – 0 | 0 |
| Crresidual | ≤ 0.3 | |
| Niresidual | ≤ 0.3 | |
| Curesidual | ≤ 0.3 | |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on 20MnTiB?
No corrosion resistance — protect with phosphate + oil, zinc or manganese phosphate; gear flanks are usually shot-peened and ground after carburizing, and plating must avoid hydrogen embrittlement (bake 190–220 °C).
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
How much does 20MnTiB cost?
20MnTiB is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
20MnTiB — frequently asked
What is 20MnTiB used for?
20MnTiB is typically used for truck gears, tractor gears and carburized shafts. In short: titanium-refined carburizing steel; truck and tractor gear grade; fair weldability at best.
What is the yield strength of 20MnTiB?
20MnTiB has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 68% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 20MnTiB easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine in the annealed (≤187 HB) or normalized state with coated carbide; sticky low-carbon chips need positive rake and good coolant — machinability roughly 55–60 % of 1212.
Can 20MnTiB be welded?
With care — weldability is rated fair (40/100). Poor to fair: carbon equivalent ~0.6 with boron, so use low-hydrogen consumables, 150–250 °C preheat and immediate stress relief; never weld after carburizing.
What surface finishes work on 20MnTiB?
No corrosion resistance — protect with phosphate + oil, zinc or manganese phosphate; gear flanks are usually shot-peened and ground after carburizing, and plating must avoid hydrogen embrittlement (bake 190–220 °C).
Can 20MnTiB be formed, bent or molded?
Hot forge 1150–850 °C then normalize/anneal; cold heading and moderate cold forming are practical only in the spheroidize-annealed condition.
What is the maximum service temperature of 20MnTiB?
20MnTiB 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.
What is the difference between 20MnTiB-A and 20MnTiB-QT200?
A is the default condition — standard delivery condition for gear-blank bar: soft, uniform structure for hobbing and shaping before carburizing. QT200: the specification heat treatment used for acceptance testing; also used for through-hardened high-strength shafts and fasteners. Yield strength is 380 MPa in A versus 980 MPa in QT200.
How much does 20MnTiB cost?
20MnTiB is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- GB/T 3077 (Alloy structural steels) (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (boron steels, carburizing) — ASM International (1991)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.