Steel P5 Carburized-HT-Cr
Finish state
AISI/SAE P5 · UNS T51605
Choose when molding corrosive resins (PVC, FR grades) or when extra cavity wear life and release are needed.
Values for the Carburized-HT-Cr condition
Other P5 tempers and conditions
P5 is listed in 4 conditions; see the grade overview at P5.
- Annealed
- Normalized
- Carburized-HT
- Carburized-HT-Cr
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault soft, as-supplied condition for machining and cold hubbing | Standard stock condition: maximum softness (105–116 HB) for cavity hubbing, machining and engraving before carburizing. | 290 | 490 | 30 | 110 HB | — |
900–925 °C air cool, grain refinement before final machining | Used after heavy forging or hubbing to refine grain and homogenize structure before the sub-critical anneal. | 340 | 560 | 26 | 150 HB | 35 W/m·K |
case 58–64 HRC | Final service condition: pack/gas carburize 900–925 °C, quench from ~790–830 °C, temper 175–260 °C for a hard wear-resistant case over a tough low-carbon core. | 750 | 1,000 | 12 | 62 HRC | — |
Carburized-HT-CrThis page Carburized, hardened and hard-chrome plated cavity | Choose when molding corrosive resins (PVC, FR grades) or when extra cavity wear life and release are needed. | 760 | 950 | 14 | 66 HRC | 7.5 % IACS |
What is P5 Carburized-HT-Cr?
P5 Carburized-HT-Cr is P5 supplied in the Carburized-HT-Cr condition — choose when molding corrosive resins (PVC, FR grades) or when extra cavity wear life and release are needed. P5 Carburized-HT-Cr has a yield strength of 760 MPa (110 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 85% of steel grades. Elongation at break is 14% and the elastic modulus is 205 GPa (29.7 Msi). P5 Carburized-HT-Cr 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). Annealed is the default condition FabDigit quotes; Carburized-HT-Cr is available on request or by drawing note.
Advantages
- Polishes to a fine finish — 88/100, better than 100% of steel grades
- Good corrosion resistance — 45/100, better than 98% of steel grades
- High strength — 760 MPa (110 ksi), better than 85% of steel grades
Limitations
- Difficult to machine — 12/100, worse than 99% of steel grades
- Difficult to weld — 10/100, worse than 99% of steel grades
- Limited formability — 5/100, worse than 99% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades
P5 Carburized-HT-Cr properties
Typical room-temperature values for P5 Carburized-HT-Cr; 24 are specific to this condition. Other listed values are P5 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
P5 Carburized-HT-Cr 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).
Mechanical15
P5 Carburized-HT-Cr has a yield strength of 760 MPa (110 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 85% of steel grades. Elongation at break is 14% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
P5 Carburized-HT-Cr is rated for continuous service to 200°C (392 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades. Thermal expansion is 12.4 µm/m·K (6.89 µin/in·°F).
Electrical3
P5 Carburized-HT-Cr conducts electricity at 7.5 % IACS, worse than 67% of steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), better than 98% of steel grades.
Sustainability4
Producing a kilogram of P5 Carburized-HT-Cr takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 40%.
Manufacturability5
P5 Carburized-HT-Cr's machinability is not recommended (12/100, worse than 99% of steel grades); weldability not recommended (10/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with P5 Carburized-HT-Cr
Is P5 easy to machine?
Very easy to machine and engrave in the annealed state (~70% of AISI 1212), but the soft low-carbon matrix tends to smear — use sharp positive-rake tools and finish before carburizing; after case hardening only grinding/EDM apply.
Can P5 be welded?
Low carbon makes repair welding practical with matching low-alloy or Ni-based filler; preheat 200–300 °C, and re-carburize or at least re-temper the repaired area.
Can P5 be formed, bent or molded?
Designed for cold hubbing (hobbing) of cavities — the master hub is pressed into the annealed blank, with stress-relief anneals between passes; hot forge 1050–1150 °C, finish above 900 °C.
What surface finishes work on P5?
Carburized case takes a high polish and texture well; hard chrome or electroless nickel plating is common for corrosive resins and added wear life; keep oiled or plated as the alloy rusts freely.
P5 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 |
|---|---|---|
| Clow carbon for carburizing / cold hubbing | ≤ 0.1 | 0.1 |
| Mn | 0.2 – 0.6 | 0.4 |
| Si | 0.1 – 0.4 | 0.25 |
| Crgives the harder, more wear-resistant case vs P2/P3 | 2 – 2.5 | 2.25 |
| Nioptional residual/addition | ≤ 0.35 | 0.2 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
P5 Carburized-HT-Cr — frequently asked
What is P5 Carburized-HT-Cr used for?
P5 Carburized-HT-Cr is typically used for carburized mold inserts, die components requiring hard cases and small precision molds. In short: easiest P-series to hob; higher-chromium case; best formability in family.
What is the yield strength of P5 Carburized-HT-Cr?
P5 Carburized-HT-Cr has a typical yield strength of 760 MPa (110 ksi) and a tensile strength of 950 MPa (138 ksi) — stronger than 85% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is P5 Carburized-HT-Cr easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 99% of steel grades). Very easy to machine and engrave in the annealed state (~70% of AISI 1212), but the soft low-carbon matrix tends to smear — use sharp positive-rake tools and finish before carburizing; after case hardening only grinding/EDM apply.
Can P5 Carburized-HT-Cr be welded?
Not readily — weldability is rated not recommended (10/100). Low carbon makes repair welding practical with matching low-alloy or Ni-based filler; preheat 200–300 °C, and re-carburize or at least re-temper the repaired area.
What surface finishes work on P5 Carburized-HT-Cr?
Carburized case takes a high polish and texture well; hard chrome or electroless nickel plating is common for corrosive resins and added wear life; keep oiled or plated as the alloy rusts freely.
Can P5 Carburized-HT-Cr be formed, bent or molded?
Designed for cold hubbing (hobbing) of cavities — the master hub is pressed into the annealed blank, with stress-relief anneals between passes; hot forge 1050–1150 °C, finish above 900 °C.
What is the maximum service temperature of P5 Carburized-HT-Cr?
P5 Carburized-HT-Cr 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.
Sources
- ASTM A681 — Standard Specification for Tool Steels Alloy — ASTM International (2022)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys (Tool Steels: P-type mold steels) — ASM International (1990)
- ASM Handbook Vol. 4: Heat Treating — Heat Treating of Tool Steels — ASM International (1991)
- Tool Steels, 5th Edition (Roberts, Krauss, Kennedy) — ASM International (1998)
- UNS T51605 alloy data — SAE/ASTM Unified Numbering System (2017)
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.