Steel 4147H
Grade
AISI/SAE 4147 · UNS G41470
4147H = h-band hardenability grade
Order when Jominy hardenability band (not just chemistry) must be guaranteed for heavy sections.
Values for the 4147H condition
Other 4147 tempers and conditions
4147 is listed in 13 conditions; see the grade overview at 4147.
Compare all 13 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Choose for maximum cold formability/heading and easiest machining of this high-carbon Cr-Mo grade. | 390 | 640 | 25 | 10 HRC | 8 % IACS |
Solution annealed | Softest condition for machining, deep drilling and forging stock before final heat treatment. | 415 | 690 | 22 | 197 HB | — |
Hot rolled | Lowest-cost mill condition for parts that will be re-heat-treated after machining or forging. | 570 | 900 | 15 | 26 HRC | 7.8 % IACS |
Cold drawn | Straight, close-tolerance bright bar for shafts machined to size without further heat treatment. | 670 | 790 | 14 | 21 HRC | 7.8 % IACS |
Normalized | Refines forging structure and gives uniform machinable hardness before quench and temper. | 690 | 1,075 | 13 | 33 HRC | 7.8 % IACS |
QT2832Default Q&T 28–32 HRC | Standard stocked quenched-and-tempered bar/forging: best balance of strength, toughness and machinability. | 860 | 965 | 17 | 30 HRC | — |
Induction hardened | Pick for journals, pins and gear teeth needing a 55–60 HRC wear case over a tough 28–32 HRC core. | 860 | 965 | 15 | 57 HRC | 7.5 % IACS |
4147HThis page H-band hardenability grade | Order when Jominy hardenability band (not just chemistry) must be guaranteed for heavy sections. | 860 | 965 | 17 | 30 HRC | 7.8 % IACS |
Q&T 32–36 HRC | Higher-strength shafting, tool joints and drill-string components still readily machinable. | 980 | 1,080 | 15 | 34 HRC | — |
Q&T 36–40 HRC | For heavily loaded gears, spindles and dies where wear resistance outranks toughness. | 1,140 | 1,240 | 13 | 38 HRC | — |
Q&T 40–44 HRC | High-strength forged tooling and wear parts; machining requires carbide, grinding often preferred. | 1,280 | 1,380 | 12 | 42 HRC | — |
Q&T 48–52 HRC | Wear-critical parts such as hammers, shear blades and mill liners; low toughness, ground finish. | 1,550 | 1,720 | 9 | 50 HRC | — |
Quenched and tempered at 205 °C | Maximum hardness/wear condition; only for compression-loaded or lightly stressed wear surfaces. | 1,650 | 2,000 | 7 | 55 HRC | — |
What is 4147H?
4147H is 4147 in the 4147H grade — order when Jominy hardenability band (not just chemistry) must be guaranteed for heavy sections. 4147H has a yield strength of 860 MPa (125 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 89% of steel grades. Elongation at break is 17% and the elastic modulus is 205 GPa (29.7 Msi). 4147H 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). QT2832 is the default condition FabDigit quotes; 4147H is available on request or by drawing note.
Advantages
- High strength — 860 MPa (125 ksi), better than 89% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
4147H properties
Typical room-temperature values for 4147H; 22 are specific to this condition. Other listed values are 4147 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
4147H 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
4147H has a yield strength of 860 MPa (125 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 89% of steel grades. Elongation at break is 17% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
4147H is rated for continuous service to 425°C (797 °F). It conducts heat at 42.6 W/m·K (24.6 BTU/hr·ft·°F), worse than 51% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
4147H conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 4147H takes about 29 MJ of energy and emits 2.2 kg of CO₂ — less than 53% of steel grades. Typical recycled content is 30%.
Manufacturability8
4147H's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (30/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 4147H
Is 4147 easy to machine?
Machine in annealed (~197 HB) or ≤32 HRC Q&T condition with rigid setups and coated carbide; above 40 HRC use ceramic/CBN or grind.
Can 4147 be welded?
Poor weldability (CE ≈ 0.85): preheat 200–320 °C, low-hydrogen consumables, interpass control and immediate post-weld temper below the tempering temperature.
Can 4147 be formed, bent or molded?
Hot forge 1150–1230 °C, finish above 900 °C and slow-cool/anneal; cold forming limited to spheroidize-annealed stock with generous radii.
What surface finishes work on 4147?
Not anodizable — use oil, manganese phosphate, black oxide, zinc or hard chrome; bake after plating to avoid hydrogen embrittlement above 40 HRC.
4147 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 |
|---|---|---|
| CSAE J404 | 0.45 – 0.5 | 0.47 |
| Mn | 0.75 – 1 | 0.88 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.8 – 1.1 | 0.95 |
| Mo | 0.15 – 0.25 | 0.2 |
| P | ≤ 0.04 | — |
| Smax; resulfurized 4147 variants run higher | ≤ 0.04 | — |
| Fe | balance | — |
4147H — frequently asked
What is 4147H used for?
4147H is typically used for forged shafts, springs and tool components. In short: higher-carbon 4140 upgrade; deep-hardening forging grade; poor weldability.
What is the yield strength of 4147H?
4147H has a typical yield strength of 860 MPa (125 ksi) and a tensile strength of 965 MPa (140 ksi) — stronger than 89% of steel grades. Strength varies by condition: see the 13 listed tempers.
Is 4147H easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in annealed (~197 HB) or ≤32 HRC Q&T condition with rigid setups and coated carbide; above 40 HRC use ceramic/CBN or grind.
Can 4147H be welded?
Not readily — weldability is rated poor (30/100). Poor weldability (CE ≈ 0.85): preheat 200–320 °C, low-hydrogen consumables, interpass control and immediate post-weld temper below the tempering temperature.
What surface finishes work on 4147H?
Not anodizable — use oil, manganese phosphate, black oxide, zinc or hard chrome; bake after plating to avoid hydrogen embrittlement above 40 HRC.
Can 4147H be formed, bent or molded?
Hot forge 1150–1230 °C, finish above 900 °C and slow-cool/anneal; cold forming limited to spheroidize-annealed stock with generous radii.
What is the maximum service temperature of 4147H?
4147H is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 4147-QT2832 and 4147-QT205?
QT2832 is the default condition — standard stocked quenched-and-tempered bar/forging: best balance of strength, toughness and machinability. QT205: maximum hardness/wear condition; only for compression-loaded or lightly stressed wear surfaces. Yield strength is 860 MPa in QT2832 versus 1,650 MPa in QT205.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1268 — Hardenability Bands for Alloy H Steels — SAE International (2019)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- GB/T 3077 (45CrMo ) — SAC (2015)
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.