Steel GCr4
GB GCr4
GCr4 is a low-chromium, approximately 1 % C bearing steel supplied hot-rolled, annealed, normalized or cold-drawn and hardened either by induction (IH-58) or by quench and temper (QT-60, QT-DS200).
Reference datasheet — GCr4 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
GCr4 tempers and conditions
GCr4 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 bar, tube and ring blanks — soft, uniform spheroidized carbides, ready for turning and subsequent hardening. | 390 | 640 | 21 | 190 HB | — |
Hot rolled | Mill as-rolled bar or tube blank; must be spheroidize annealed before machining or cold forming. | 480 | 850 | 12 | 25 HRC | 7 % IACS |
Normalized | Used to break up network carbides or banded structure in large forged rings before spheroidizing. | 520 | 950 | 10 | 30 HRC | 7 % IACS |
Cold drawn | Cold-drawn bar or bearing tube for close size tolerance and better surface before ring parting. | 600 | 780 | 10 | 20 HRC | 7 % IACS |
Q&T + 200–250 °C stabilizing temper | Higher tempering for bearings running warm (up to ~180–200 °C) where dimensional stability outranks peak hardness. | 1,700 | 1,950 | 1 | 58 HRC | 5.4 % IACS |
IH 58–62 HRC | The design condition for GCr4: hard, compressively stressed raceway layer over a tough unhardened core — chosen for large railway and wind-gear bearing rings. | 2,100 | 1 | 60 HRC | 40 W/m·K | |
Q&T 60–64 HRC | Through-hardened small rings and rollers; limited to thin sections because GCr4 is deliberately low in hardenability. | 2,250 | 0.5 | 62 HRC | — |
What is GCr4?
GCr4 is a low-chromium, approximately 1 % C bearing steel supplied hot-rolled, annealed, normalized or cold-drawn and hardened either by induction (IH-58) or by quench and temper (QT-60, QT-DS200). It is chosen for large-section bearing rings and slewing bearings where selective surface hardening is preferred over through-hardening, leaving a tougher core. Annealed bar runs about 390 MPa yield, 640 MPa tensile, 21 % elongation and 190 HB, with service to roughly 250 °C and no inherent corrosion resistance. It is effectively unweldable at this carbon level; 100Cr6/GCr15 is the usual alternative when through-hardening the full section is acceptable. GCr4 has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,420°C (2,588 °F). GCr4 has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 64% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi).
What is GCr4 used for?
- Large induction-hardened bearing rings
- Slewing bearing raceways
- Crane and excavator slew rings
- Turntable bearing inner and outer rings
- Heavy thrust washers
- Locally hardened shaft journals
Advantages
- Polishes to a fine finish — 85/100, better than 99% of steel grades
Limitations
- Difficult to weld — 15/100, worse than 91% of steel grades
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
GCr4 properties
Typical room-temperature values for GCr4-A; bars are the position among steel grades.
Physical3
GCr4 has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical14
GCr4 has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 64% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
GCr4 is rated for continuous service to 250°C (482 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
GCr4 conducts electricity at 7 % IACS, worse than 74% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of GCr4 takes about 31 MJ of energy and emits 2.3 kg of CO₂ — more than 64% of steel grades. Typical recycled content is 25%.
Manufacturability8
GCr4's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (15/100); formability fair (40/100).
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. GCr4 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with GCr4
Is GCr4 easy to machine?
Turn and drill only in the spheroidize-annealed state (≤207 HB) with coated carbide, low speed and rigid setup; after hardening use CBN hard turning or grinding.
Can GCr4 be welded?
Effectively unweldable at ~1 %C — if repair is unavoidable, preheat 300–400 °C, use low-hydrogen filler and immediately post-weld temper.
Can GCr4 be formed, bent or molded?
Ring blanks are hot forged/ring-rolled at 1050–1120 °C then slowly cooled and spheroidize annealed (780–800 °C soak, slow cool to ~700 °C) to avoid network carbides.
GCr4 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 | 0.95 – 1.05 | 1 |
| Si | 0.15 – 0.3 | 0.23 |
| Mn | 0.15 – 0.3 | 0.25 |
| Crdeliberately low for shallow hardening | 0.35 – 0.5 | 0.43 |
| Moresidual | ≤ 0.08 | |
| Niresidual | ≤ 0.25 | |
| Curesidual; Ni+Cu ≤ 0.50 | ≤ 0.2 | |
| P | ≤ 0.03 | |
| S | ≤ 0.02 | |
| O≤12 ppm for high-grade bearing quality | ≤ 0 | |
| Ti | ≤ 0.01 | |
| Fe | balance |
What surface finishes work on GCr4?
Raceways are hard-turned then ground and superfinished; corrosion protection by oiling, manganese phosphate or black oxide — no anodizing possible.
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 GCr4 cost?
GCr4 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.
GCr4 — frequently asked
What is GCr4 used for?
GCr4 is typically used for large induction-hardened bearing rings, slewing bearing raceways, crane and excavator slew rings, turntable bearing inner and outer rings, heavy thrust washers and locally hardened shaft journals. In short: induction-hardening bearing steel; leaner Cr than 100Cr6; tough core, hard raceway.
What is the yield strength of GCr4?
GCr4 has a typical yield strength of 390 MPa (56.6 ksi) and a tensile strength of 640 MPa (92.8 ksi) — weaker than 64% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is GCr4 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Turn and drill only in the spheroidize-annealed state (≤207 HB) with coated carbide, low speed and rigid setup; after hardening use CBN hard turning or grinding.
Can GCr4 be welded?
Not readily — weldability is rated poor (15/100). Effectively unweldable at ~1 %C — if repair is unavoidable, preheat 300–400 °C, use low-hydrogen filler and immediately post-weld temper.
What surface finishes work on GCr4?
Raceways are hard-turned then ground and superfinished; corrosion protection by oiling, manganese phosphate or black oxide — no anodizing possible.
Can GCr4 be formed, bent or molded?
Ring blanks are hot forged/ring-rolled at 1050–1120 °C then slowly cooled and spheroidize annealed (780–800 °C soak, slow cool to ~700 °C) to avoid network carbides.
What is the maximum service temperature of GCr4?
GCr4 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between GCr4-A and GCr4-CD?
A is the default condition — standard delivery condition for bar, tube and ring blanks — soft, uniform spheroidized carbides, ready for turning and subsequent hardening. CD: cold-drawn bar or bearing tube for close size tolerance and better surface before ring parting. Yield strength is 390 MPa in A versus 600 MPa in CD.
How much does GCr4 cost?
GCr4 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
- ГОСТ 801 Сталь подшипниковая (ШХ4) — Gosstandart (1978)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys (Bearing Steels) — ASM International (1990)
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.