Steel 15Kh
GOST 15Kh (15Х)
15Kh (15Х) is a low-alloy chromium case-hardening steel from the GOST structural steel family, with a low-carbon core that is strengthened by carburizing.
Reference datasheet — 15Kh 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 Q&T condition
15Kh tempers and conditions
15Kh is supplied in 6 conditions, soft to hard. Q&T is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition — choose for deep machining, cold heading or cold extrusion before carburizing. | 300 | 490 | 28 | 160 HB | — |
Hot rolled | Mill delivery condition for bar and billet that will be machined and then carburized. | 330 | 540 | 24 | 170 HB | — |
Normalized | Uniform fine-grain structure with better machined-surface finish than annealed; standard pre-carburizing condition. | 350 | 560 | 22 | 11 HRC | 9 % IACS |
Cold drawn | Bright, close-tolerance bar for pins, bushings and shafts machined with minimal stock removal. | 520 | 640 | 12 | 200 HB | — |
Q&TDefault Quenched and tempered | The GOST 4543 acceptance condition — use these numbers for the core of small hardened parts and for through-hardened pins. | 540 | 750 | 14 | 20 HRC | — |
Carburized + quenched + 180 °C temper | Final service condition for gears and pins: hard wear-resistant case (0.5–1.2 mm) over a tough medium-strength core. | 590 | 800 | 12 | 58 HRC | — |
What is 15Kh?
15Kh (15Х) is a low-alloy chromium case-hardening steel from the GOST structural steel family, with a low-carbon core that is strengthened by carburizing. It suits lightly loaded gears, pins and small shafts where full Ni-Cr hardenability is unnecessary, and is stocked as hot-rolled, annealed, normalized and cold-drawn bar. Quenched and tempered it gives about 540 MPa yield, 750 MPa tensile, 14 % elongation and 217 HB (20 HRC), with service to about 200 °C and machinability 45. It has no corrosion resistance and limited hardenability in larger sections; 20Kh is the nearest and more widely stocked alternative. 15Kh has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,425°C (2,597 °F). 15Kh has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 70% of steel grades. Elongation at break is 14% and the elastic modulus is 212 GPa (30.7 Msi).
What is 15Kh used for?
- Lightly loaded small gears
- Pins and pivot pins
- Small shafts and spindles
- Bushings
- Cams and levers
- Sprockets
- Wear-facing hardware
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Limited ductility — 14%, worse than 75% of steel grades
15Kh properties
Typical room-temperature values for 15Kh-Q&T; bars are the position among steel grades.
Physical3
15Kh has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
15Kh has a yield strength of 540 MPa (78.3 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 70% of steel grades. Elongation at break is 14% and the elastic modulus is 212 GPa (30.7 Msi).
Thermal6
15Kh is rated for continuous service to 200°C (392 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
15Kh conducts electricity at 8.2 % IACS, better than 61% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 15Kh takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
15Kh's machinability is fair (45/100, worse than 65% of steel grades); weldability good (55/100); formability good (60/100).
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. 15Kh is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 15Kh
Is 15Kh easy to machine?
Machine in the annealed or normalized state (≈60–65 % of AISI 1212); leave 0.1–0.3 mm grinding stock for post-carburizing finishing.
Can 15Kh be welded?
Weldable with low-hydrogen electrodes at 150–250 °C preheat plus post-weld stress relief; do not weld carburized surfaces.
Can 15Kh be formed, bent or molded?
Good hot forgeability at 1150–850 °C and acceptable cold upsetting when spheroidize annealed; normalize after forging.
15Kh 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 | 0.12 – 0.18 | 0.15 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 0.4 – 0.7 | 0.55 |
| Cr | 0.7 – 1 | 0.85 |
| Niresidual | ≤ 0.3 | — |
| Curesidual | ≤ 0.3 | — |
| Simpurity | ≤ 0.04 | — |
| Pimpurity | ≤ 0.04 | — |
| Fe | balance | — |
What surface finishes work on 15Kh?
No anodizing — protect with phosphating and oil, black oxide, or zinc/nickel plating; ground and honed case surfaces give best fatigue life.
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
Equivalent designations
Standards and trade names that resolve to Steel 15Kh in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- GOST
- 15Х
How much does 15Kh cost?
15Kh 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.
15Kh — frequently asked
What is 15Kh used for?
15Kh is typically used for lightly loaded small gears, pins and pivot pins, small shafts and spindles, bushings, cams and levers and sprockets. In short: entry-level chromium case steel; low-cost carburizing grade; weldable before carburizing.
What is the yield strength of 15Kh?
15Kh has a typical yield strength of 540 MPa (78.3 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 70% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is 15Kh easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machine in the annealed or normalized state (≈60–65 % of AISI 1212); leave 0.1–0.3 mm grinding stock for post-carburizing finishing.
Can 15Kh be welded?
Yes — weldability is rated good (55/100). Weldable with low-hydrogen electrodes at 150–250 °C preheat plus post-weld stress relief; do not weld carburized surfaces.
What surface finishes work on 15Kh?
No anodizing — protect with phosphating and oil, black oxide, or zinc/nickel plating; ground and honed case surfaces give best fatigue life.
Can 15Kh be formed, bent or molded?
Good hot forgeability at 1150–850 °C and acceptable cold upsetting when spheroidize annealed; normalize after forging.
What is the maximum service temperature of 15Kh?
15Kh is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 15Kh Q&T and 15Kh-A?
Q&T is the default condition — the GOST 4543 acceptance condition — use these numbers for the core of small hardened parts and for through-hardened pins. A: softest condition — choose for deep machining, cold heading or cold extrusion before carburizing. Yield strength is 540 MPa in Q&T versus 300 MPa in A.
How much does 15Kh cost?
15Kh 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
- GOST 4543 — Alloyed structural steel bars — Gosstandart / Rosstandart (2016)
- GB/T 3077 (15Cr equivalent) — SAC (2015)
- Marochnik Stali i Splavov — grade 15Kh property tables — Marochnik (2020)
- ASM Handbook Vol.1 & Vol.4 — carburizing low-alloy steels — 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.