Steel 33B2
EN 33B2
33B2 (1.5514) is a low-carbon boron-treated alloy steel in the EN 10083 family, where trace boron buys hardenability far more cheaply than Cr or Cr-Mo additions.
Reference datasheet — 33B2 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 +AC+C condition
33B2 tempers and conditions
33B2 is supplied in 8 conditions, soft to hard. +AC+C is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Spheroidize annealed | Pick for the softest, most ductile state before multi-station cold heading or deep cold extrusion of larger parts. | 320 | 510 | 24 | 150 HB | — |
Annealed | General soft condition for machining or moderate cold forming when full spheroidizing is not specified. | 340 | 550 | 22 | 160 HB | — |
Hot rolled | Cheapest mill condition; feedstock for further annealing or for hot forging, not for severe cold heading. | 390 | 640 | 20 | 190 HB | — |
+AC+CDefault Spheroidize annealed and cold drawn | Standard stocked cold-heading wire: sized, straight, phosphate/soap coated and soft enough to head, then quench-tempered as a finished part. | 520 | 620 | 12 | 180 HB | — |
Cold drawn | Use where dimensional accuracy and higher as-delivered strength matter more than heading ductility (turned parts, light upsetting). | 580 | 680 | 10 | 200 HB | — |
+QT | The workhorse condition for headed M5–M16 bolts and screws: quench from ~870 °C, temper ~500–550 °C. | 720 | 880 | 14 | 29 HRC | — |
+QT | High-strength option for small-diameter boron-steel fasteners (temper ~420–470 °C); watch hydrogen embrittlement after electroplating and limit section size. | 960 | 1,080 | 10 | 35 HRC | — |
Hardenability-controlled quality, hardened | Order +H when the Jominy band must be guaranteed; the as-quenched (water/oil from 860–890 °C) martensite reaches ~50 HRC and must be tempered before use. | 1,300 | 1,650 | 4 | 50 HRC | — |
What is 33B2?
33B2 (1.5514) is a low-carbon boron-treated alloy steel in the EN 10083 family, where trace boron buys hardenability far more cheaply than Cr or Cr-Mo additions. It is used mainly as cold-heading wire and bar for through-hardened medium-strength fasteners; in the annealed or cold-drawn state on file it shows about 520 MPa yield, 620 MPa tensile, 12 % elongation and 180 HB (89 HRB), with formability rated 75. Weldability is limited (score 45) because boron plus 0.33 % C gives a hard, crack-prone HAZ, and the steel has no inherent corrosion resistance, so plating or zinc-flake coating is required. 38B2 is the nearest step up when higher tempered strength is needed. 33B2 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). 33B2 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 67% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
What is 33B2 used for?
- bolts
- cold-headed fasteners
- automotive hardware
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Forms and bends easily — 75/100, better than 90% of steel grades
- Easy to machine — 62/100, better than 89% of steel grades
Limitations
- Limited ductility — 12%, worse than 84% of steel grades
33B2 properties
Typical room-temperature values for 33B2-+AC+C; bars are the position among steel grades.
Physical3
33B2 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
33B2 has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 67% of steel grades. Elongation at break is 12% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
33B2 is rated for continuous service to 350°C (662 °F). It conducts heat at 46 W/m·K (26.6 BTU/hr·ft·°F), better than 71% of steel grades. Thermal expansion is 12.1 µm/m·K (6.72 µin/in·°F).
Electrical3
33B2 conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 33B2 takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
33B2's machinability is good (62/100, better than 89% of steel grades); weldability fair (45/100); formability very good (75/100).
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. 33B2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 33B2
Is 33B2 easy to machine?
Machines like 1035 in the +AC/+AC+C states (≈65 % of 1212); it is low-sulphur so use sharp positive tooling and good chip control, and expect a drop to ~40–50 % after quench-tempering.
Can 33B2 be welded?
Weldable with care but boron plus 0.33 %C gives a hard, crack-prone HAZ — use low-hydrogen consumables, 150–250 °C preheat and post-weld temper; welding after Q&T destroys the fastener properties.
Can 33B2 be formed, bent or molded?
Designed for cold heading and cold extrusion in the spheroidize-annealed condition with phosphate+soap or polymer lubricant; upset ratios of 2.5–3 diameters are routine, and inter-stage annealing is rarely needed.
33B2 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 |
|---|---|---|
| Cgrade-defining carbon level | 0.3 – 0.36 | 0.33 |
| Sikept low for cold heading | ≤ 0.3 | 0.15 |
| Mn | 0.5 – 0.8 | 0.65 |
| P | ≤ 0.03 | 0.02 |
| Smax; low-S for cold formability | ≤ 0.03 | 0.01 |
| Beffective (soluble) boron gives the hardenability boost | 8×10⁻⁴ – 0.01 | 0 |
| Altotal Al (or Ti) to fix nitrogen and protect the boron effect | ≥ 0.02 | 0.03 |
| Curesidual, max | ≤ 0.25 | 0.1 |
| Crresidual, max | ≤ 0.3 | 0.1 |
| Niresidual, max | ≤ 0.3 | 0.08 |
| Fe | balance |
What surface finishes work on 33B2?
No inherent corrosion resistance: zinc electroplate (with 190–220 °C bake within 4 h for ≥1000 MPa parts), zinc-flake (Dacromet/Geomet), zinc-nickel or manganese phosphate + oil are the usual protective systems.
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 33B2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.5514
How much does 33B2 cost?
33B2 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
33B2 — frequently asked
What is 33B2 used for?
33B2 is typically used for bolts, cold-headed fasteners and automotive hardware. In short: low-cost boron hardenability; cold-heading fastener steel; cheaper than 41Cr4.
What is the yield strength of 33B2?
33B2 has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 67% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 33B2 easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines like 1035 in the +AC/+AC+C states (≈65 % of 1212); it is low-sulphur so use sharp positive tooling and good chip control, and expect a drop to ~40–50 % after quench-tempering.
Can 33B2 be welded?
With care — weldability is rated fair (45/100). Weldable with care but boron plus 0.33 %C gives a hard, crack-prone HAZ — use low-hydrogen consumables, 150–250 °C preheat and post-weld temper; welding after Q&T destroys the fastener properties.
What surface finishes work on 33B2?
No inherent corrosion resistance: zinc electroplate (with 190–220 °C bake within 4 h for ≥1000 MPa parts), zinc-flake (Dacromet/Geomet), zinc-nickel or manganese phosphate + oil are the usual protective systems.
Can 33B2 be formed, bent or molded?
Designed for cold heading and cold extrusion in the spheroidize-annealed condition with phosphate+soap or polymer lubricant; upset ratios of 2.5–3 diameters are routine, and inter-stage annealing is rarely needed.
What is the maximum service temperature of 33B2?
33B2 is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 33B2 cost?
33B2 is a budget-cost steel ($), 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
- EN 10263-4 — Steel rod, bars and wire for cold heading and cold extrusion: steels for quenching and tempering — CEN (2017)
- EN 10263-1 — General technical delivery conditions (delivery states +A, +AC, +C, +AC+C, +H) — CEN (2018)
- ISO 898-1 — Mechanical properties of fasteners, property classes 8.8 / 9.8 / 10.9 — ISO (2013)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys (boron steels, carbon steel physical data) — ASM International (1990)
- ASM Handbook Vol. 4 — Heat Treating (hardenability of boron steels, Jominy behaviour) — ASM International (1991)
- Cold-heading quality boron steel wire rod datasheets (ovako / Saarstahl / Ø CHQ wire producers) — various steel producers (2022)
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.