9Cr18Mo vs 9Cr18MoV vs 1.7729: Which High-Performance Steel Is Right for Your Application?
At FULLERKREG, we supply precision fasteners and engineered components across a wide range of high-performance steels. 9Cr18Mo and 9Cr18MoV are high-carbon martensitic stainless steels engineered for maximum hardness and wear resistance in bearing and cutting applications, while 1.7729 (20CrMoVTiB4-10) is a low-alloy chromium-molybdenum-vanadium steel designed for high-temperature bolting and fastener applications per EN 10269.
This guide provides a direct technical comparison of all three grades per their respective standards, covering chemical composition and mechanical properties to support your material selection decision.
Alloy Overview
- 9Cr18Mo — A high-carbon, high-chromium martensitic stainless steel with molybdenum addition for improved hardenability and corrosion resistance. After quench and temper, achieves HRC 58–62. Governed by GB/T 1220 9Cr18Mo.
- 9Cr18MoV — An enhanced version of 9Cr18Mo with vanadium addition for finer carbide distribution, improved wear resistance, and better edge retention. Governed by GB/T 1220 9Cr18MoV.
- 1.7729 / 20CrMoVTiB4-10 — A low-alloy Cr-Mo-V-Ti-B steel for high-temperature bolting and fasteners per EN 10269. Boron and titanium additions enhance hardenability and creep resistance at elevated temperatures up to ~550°C. Governed by EN 10269 / W.Nr. 1.7729.
Chemical Composition Comparison
All values are weight percent (%). Min = minimum required; Max = maximum allowed per respective standard.
9Cr18Mo — GB/T 1220
| C | Mn | P | S | Si | Cr | Ni | Mo | N | Cu | |
|---|---|---|---|---|---|---|---|---|---|---|
| Min | 0.95 | — | — | — | — | 16.00 | — | 0.40 | — | — |
| Max | 1.10 | 0.80 | 0.040 | 0.030 | 0.80 | 18.00 | 0.60 | 0.70 | — | — |
9Cr18MoV — GB/T 1220
| C | Mn | P | S | Si | Cr | Ni | Mo | V | Cu | |
|---|---|---|---|---|---|---|---|---|---|---|
| Min | 0.85 | — | — | — | — | 17.00 | — | 1.00 | 0.07 | — |
| Max | 0.95 | 0.80 | 0.040 | 0.030 | 0.80 | 19.00 | 0.60 | 1.30 | 0.12 | — |
1.7729 / 20CrMoVTiB4-10 — EN 10269
| C | Si | Mn | P | S | Al | B | Cr | Mo | Ni | V | Ti | As | Sn | Cu | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | 0.17 | — | 0.35 | — | — | 0.015 | 0.001 | 0.90 | 0.90 | — | 0.60 | 0.07 | — | — | — |
| Max | 0.23 | 0.40 | 0.75 | 0.020 | 0.015 | 0.080 | 0.010 | 1.20 | 1.10 | 0.20 | 0.80 | 0.15 | 0.020 | 0.020 | 0.20 |
Mechanical Properties Comparison
9Cr18Mo & 9Cr18MoV — Annealed Delivery Condition (GB/T 1220)
| Grade | Standard | Delivery Condition | Hardness HB (max) | Hardness after Q+T |
|---|---|---|---|---|
| 9Cr18Mo | GB/T 1220 | Annealed | ≤269 | HRC 58–62 (typical) |
| 9Cr18MoV | GB/T 1220 | Annealed | ≤269 | HRC 58–62 (typical) |
Note: Both 9Cr18Mo and 9Cr18MoV are supplied in annealed condition (HB ≤269) for subsequent hardening and tempering by the end user. Final hardness and wear properties are achieved after quench and temper heat treatment.
1.7729 / 20CrMoVTiB4-10 — Mechanical Properties (EN 10269, Quenched & Tempered)
| Tensile Strength Rm (N/mm²) | Yield Strength Rp0.2 (N/mm²) min | Elongation A (%) min | Reduction of Area (%) min |
|---|---|---|---|
| 820–1000 | ≥660 | ≥15 | ≥50 |
Key Differences at a Glance
| Parameter | 9Cr18Mo | 9Cr18MoV | 1.7729 (20CrMoVTiB4-10) |
|---|---|---|---|
| Governing standard | GB/T 1220 | GB/T 1220 | EN 10269 / W.Nr. 1.7729 |
| Steel family | Martensitic stainless | Martensitic stainless | Low-alloy Cr-Mo-V-Ti-B |
| C content (%) | 0.95–1.10 | 0.85–0.95 | 0.17–0.23 |
| Cr content (%) | 16.0–18.0 | 17.0–19.0 | 0.90–1.20 |
| Mo content (%) | 0.40–0.70 | 1.00–1.30 | 0.90–1.10 |
| V content (%) | — | 0.07–0.12 | 0.60–0.80 |
| Special additions | — | V (carbide refinement) | Ti, B, Al (hardenability + creep) |
| Delivery condition | Annealed (HB ≤269) | Annealed (HB ≤269) | Quenched & Tempered |
| Tensile Strength (N/mm²) | Per Q+T spec | Per Q+T spec | 820–1000 |
| Yield Strength min (N/mm²) | Per Q+T spec | Per Q+T spec | ≥660 |
| Hardness after Q+T | HRC 58–62 | HRC 58–62 | ~248–302 HB |
| Max service temperature | ~200°C (corrosion-resistant) | ~200°C (corrosion-resistant) | ~550°C (creep-resistant bolting) |
| Corrosion resistance | Good (dry/mild environments) | Good (dry/mild environments) | Limited (low Cr, not stainless) |
| Primary application | Precision bearings, cutting tools | High-wear bearings, premium cutlery | High-temperature bolting & fasteners |
Application Selection Guide
Choose 9Cr18Mo when:
- High hardness (HRC 58–62) and wear resistance are required with moderate corrosion resistance
- Bearing applications in mildly corrosive or humid environments are specified
- Molybdenum addition provides improved hardenability and through-hardening in larger sections
- Typical applications: precision ball and roller bearings, stainless bearing rings, surgical instrument components, corrosion-resistant wear plates, high-hardness fasteners in dry environments
Choose 9Cr18MoV when:
- Maximum wear resistance and edge retention are required beyond what 9Cr18Mo provides
- Vanadium carbides provide a finer microstructure and superior abrasion resistance
- Premium cutting tool or high-performance bearing applications justify the higher alloy content
- Typical applications: premium knife and blade steels, high-performance bearing components, precision cutting tools, wear-resistant inserts, high-end surgical instruments
Choose 1.7729 / 20CrMoVTiB4-10 when:
- High-temperature bolting or fastener applications require strength retention up to ~550°C
- EN 10269 compliance is specified for pressure vessel, turbine, or power plant bolting
- Good ductility (elongation ≥15%, reduction of area ≥50%) must be maintained alongside high strength
- Typical applications: steam turbine bolting, pressure vessel studs and nuts, power plant flange bolting, high-temperature pipe flanges, boiler fasteners per EN 10269
FULLERKREG Supply Capabilities
FULLERKREG supplies precision fasteners and engineered components in 9Cr18Mo, 9Cr18MoV, and 1.7729:
- Material Test Certificates (MTC) — EN 10204 3.1 / 3.2 available on request
- GB/T 1220 / EN 10269 compliance — rod and bar forms for fastener and structural applications
- 9Cr18Mo / 9Cr18MoV in annealed or hardened & tempered condition — per customer specification
- 1.7729 fasteners to EN 10269 — studs, bolts, and nuts for high-temperature pressure equipment
- Bulk wholesale pricing — OEM and MRO procurement with competitive lead times
- Global shipping — from our manufacturing base in China to customers worldwide
Need a quote or technical consultation for 9Cr18Mo, 9Cr18MoV, or 1.7729 fasteners? Contact FULLERKREG with your specification and our engineering team will respond promptly.
FULLERKREG — Precision Fasteners. Global Standards. Reliable Supply.