Steel 50B44-SA (Spheroidize annealed)
Heat-treated state
EN 50B44 · UNS G50441
Pick for cold heading, deep drawing or heavy cold forming of blades and fasteners.
Values for the SA condition
Other 50B44 tempers and conditions
50B44 is listed in 11 conditions; see the grade overview at 50B44.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SAThis page Spheroidize annealed | Pick for cold heading, deep drawing or heavy cold forming of blades and fasteners. | 350 | 600 | 25 | 174 HB | 8 % IACS |
ADefault Solution annealed | Standard stocking condition for machining, cold forming and blanking before hardening. | 380 | 640 | 22 | 187 HB | — |
Hot rolled | Cheapest mill condition for parts that will be re-austenitized and quenched anyway. | 430 | 725 | 16 | 207 HB | — |
Normalized | Uniform fine grain and predictable response before hardening; also used as a supply condition for forgings. | 520 | 840 | 20 | 24 HRC | — |
Cold drawn | Tighter tolerance and better surface for machined shafts and pins; higher strength, lower ductility. | 640 | 760 | 12 | 17 HRC | 8 % IACS |
Q&T 650 °C | Softest quenched-and-tempered condition — maximum ductility and machinability, still through-hardened structure. | 830 | 950 | 20 | 30 HRC | — |
Q&T 540 °C | General machinery condition for shafts, links and high-strength fasteners needing toughness. | 1,100 | 1,210 | 15 | 38 HRC | — |
Q&T 425 °C | Balance of strength and shock resistance for plow shares, mower blades and track components. | 1,380 | 1,500 | 12 | 44 HRC | — |
commercial hardened wear-part condition | The hardness band most agricultural-tool suppliers ship 50B44 strip/blades in; buy this when hardness, not a tempering recipe, is specified. | 1,450 | 1,620 | 11 | 47 HRC | — |
Q&T 315 °C | Standard wear-part condition: still very hard but with usable impact resistance. | 1,580 | 1,790 | 10 | 50 HRC | — |
Q&T 205 °C | Maximum hardness and wear resistance for tillage points and cutting edges; lowest toughness. | 1,650 | 2,000 | 9 | 55 HRC | — |
What is 50B44-SA?
50B44-SA is 50B44 heat treated to SA — pick for cold heading, deep drawing or heavy cold forming of blades and fasteners. 50B44-SA has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 74% of steel grades. Elongation at break is 25% and the elastic modulus is 205 GPa (29.7 Msi). 50B44-SA has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). A is the default condition FabDigit quotes; SA is available on request or by drawing note.
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Easy to machine — 62/100, better than 89% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
50B44-SA properties
Typical room-temperature values for 50B44-SA; 21 are specific to this condition. Other listed values are 50B44 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
50B44-SA has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical13
50B44-SA has a yield strength of 350 MPa (50.8 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 74% of steel grades. Elongation at break is 25% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
50B44-SA is rated for continuous service to 400°C (752 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 71% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
50B44-SA conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 50B44-SA takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
50B44-SA's machinability is good (62/100, better than 89% of steel grades); weldability poor (32/100); formability good (55/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 50B44-SA
Is 50B44 easy to machine?
Machine in the annealed or spheroidized condition (~62 % of 1212) with carbide at moderate speed; above 45 HRC switch to grinding, CBN or hard turning.
Can 50B44 be welded?
Poor weldability — boron plus 0.45 % C gives high carbon equivalent; use low-hydrogen consumables, 200–300 °C preheat, controlled interpass and immediate temper or post-weld heat treatment.
Can 50B44 be formed, bent or molded?
Cold form, blank, roll or press only in the annealed/spheroidized state; hot forge 1150–1200 °C, finish above 900 °C, then normalize or anneal to restore uniform grain before hardening.
What surface finishes work on 50B44?
Austenitize 830–860 °C, quench in oil (thin sections) or water/polymer, temper 175–650 °C; protect with paint, phosphate-and-oil, black oxide or zinc — avoid acid pickling of hardened parts to prevent hydrogen embrittlement.
50B44 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 | 0.43 – 0.48 | 0.46 |
| Mn | 0.75 – 1 | 0.88 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.4 – 0.6 | 0.5 |
| Bhardenability boron; requires Ti/Al to fix nitrogen | 5×10⁻⁴ – 0 | 0 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Fe | balance | — |
50B44-SA — frequently asked
What is 50B44-SA used for?
50B44-SA is typically used for springs, high-strength bolts and wear parts. In short: deep hardening, low alloy cost; chromium-boron spring steel; anneal before cold forming.
What is the yield strength of 50B44-SA?
50B44-SA has a typical yield strength of 350 MPa (50.8 ksi) and a tensile strength of 600 MPa (87 ksi) — weaker than 74% of steel grades. Strength varies by condition: see the 11 listed tempers.
Is 50B44-SA easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machine in the annealed or spheroidized condition (~62 % of 1212) with carbide at moderate speed; above 45 HRC switch to grinding, CBN or hard turning.
Can 50B44-SA be welded?
Not readily — weldability is rated poor (32/100). Poor weldability — boron plus 0.45 % C gives high carbon equivalent; use low-hydrogen consumables, 200–300 °C preheat, controlled interpass and immediate temper or post-weld heat treatment.
What surface finishes work on 50B44-SA?
Austenitize 830–860 °C, quench in oil (thin sections) or water/polymer, temper 175–650 °C; protect with paint, phosphate-and-oil, black oxide or zinc — avoid acid pickling of hardened parts to prevent hydrogen embrittlement.
Can 50B44-SA be formed, bent or molded?
Cold form, blank, roll or press only in the annealed/spheroidized state; hot forge 1150–1200 °C, finish above 900 °C, then normalize or anneal to restore uniform grain before hardening.
What is the maximum service temperature of 50B44-SA?
50B44-SA is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 50B44-A and 50B44-QT205?
A is the default condition — standard stocking condition for machining, cold forming and blanking before hardening. QT205: maximum hardness and wear resistance for tillage points and cutting edges; lowest toughness. Yield strength is 380 MPa in A versus 1,650 MPa in QT205.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1268 — Hardenability Bands for Carbon and Alloy H Steels — SAE International (2019)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM International (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (boron steels, hardenability) — ASM International (1991)
- Machinery's Handbook, 31st ed. — Industrial Press (2020)
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.