Steel 35#
GB 35#
35# is a medium-carbon steel of about 0.36 % C, supplied hot rolled, annealed, normalized, cold drawn or quenched and tempered, including a 28–32 HRC condition.
Values for the HR condition
35# tempers and conditions
35# is supplied in 7 conditions, soft to hard. HR is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Pick the fully annealed state (~860 °C, furnace cooled) for the lowest hardness and most uniform structure — best suited to heavy cutting, cold forming or softening before further heat treatment. | 300 | 520 | 27 | 150 HB | — |
HRDefault Hot rolled | Take as-rolled bar or plate as the standard stock for machining, forging blanks or low-to-medium load structural parts at 330 MPa yield and 160 HB. | 330 | 560 | 22 | 160 HB | — |
Normalized | Choose normalizing at 850–880 °C with air cooling to refine grain and remove forging or hot-rolling banding; this is the GB/T 699 property sampling state and the usual delivery state for welded structures. | 345 | 580 | 23 | 170 HB | — |
Quenched and tempered | Pick the general-purpose water quench from 850 °C with 550–650 °C temper for balanced strength and toughness in medium-load shafts, connecting rods and flange bolts; sections over ~40 mm will not harden through. | 470 | 700 | 19 | 18 HRC | — |
Induction / flame surface hardened and tempered | Use induction or flame hardening over a quenched-and-tempered core to obtain a 45–55 HRC wear layer on journals, guide faces and pin bores; machining and welding after hardening are impractical. | 470 | 700 | 16 | 50 HRC | 9.5 % IACS |
Cold drawn | Use cold drawn bar for tight dimensional accuracy, good surface finish and raised strength in no-machining shafts, pins and screw-machine parts; ductility and residual stress are the limits. | 520 | 640 | 13 | 190 HB | — |
quenched and medium tempered (~480–540 °C) | Choose the ~480–540 °C medium temper at 28–32 HRC for small-section shafts, pins and gear blanks needing wear resistance and higher fatigue strength; control quench cracking and accept lower machinability. | 760 | 950 | 14 | 30 HRC | — |
What is 35#?
35# is a medium-carbon steel of about 0.36 % C, supplied hot rolled, annealed, normalized, cold drawn or quenched and tempered, including a 28–32 HRC condition. It is used for general shafting, fasteners and machined structural parts where the default 330 MPa yield and 560 MPa tensile are sufficient and cost matters. Weldability is restricted by the carbon level, corrosion resistance is that of plain carbon steel and formability is moderate (cold bend radii ≥2t). It is comparable to AISI 1035; use a 0.45 % C grade for higher strength, or a low-carbon steel where welding dominates. 35# 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). 35# has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 78% of steel grades. Elongation at break is 22% and the elastic modulus is 207 GPa (30 Msi).
What is 35# used for?
- Shafts
- Industrial bolts
- Crankshafts
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Conducts heat well — 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
Limitations
- Low fracture toughness — 55 MPa·√m (50.1 ksi·√in), worse than 82% of steel grades
- Low strength — 330 MPa (47.9 ksi), worse than 78% of steel grades
35# properties
Typical room-temperature values for 35#-HR; bars are the position among steel grades.
Physical3
35# 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
35# has a yield strength of 330 MPa (47.9 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 78% of steel grades. Elongation at break is 22% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
35# is rated for continuous service to 400°C (752 °F). It conducts heat at 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades. Thermal expansion is 11.6 µm/m·K (6.44 µin/in·°F).
Electrical3
35# conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of 35# takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability8
35#'s machinability is good (60/100, better than 83% of steel grades); weldability good (55/100); formability fair (45/100).
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. 35# is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 35#
Is 35# easy to machine?
Machinability is best in the normalized or quenched-and-tempered condition, at 60–70 % of AISI 1212; annealed material tends to smear and burr. Work in the 170–210 HB range with generous coolant.
Can 35# be welded?
At C ≈ 0.36 % weldability is restricted: preheat heavy sections to 100–200 °C, use low-hydrogen electrodes or ER70S-6 wire, and stress relieve at 600–650 °C after welding to prevent cold cracking.
Can 35# be formed, bent or molded?
Hot forge at 1150–850 °C and normalize after forging. Cold bend radii should be at least 2t, and cold-drawn stock is best stress-relief annealed before bending.
Manufacturability
The process limits FabDigit applies to 35#. Every 35# part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better60 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Better45 / 100 |
|---|---|
| Weldability | Better55 / 100 |
35# 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 |
|---|---|---|
| CGB/T 699 35 | 0.32 – 0.4 | 0.36 |
| Si | 0.17 – 0.37 | 0.27 |
| Mn | 0.5 – 0.8 | 0.65 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Crresidual element | ≤ 0.25 | 0.1 |
| Niresidual element | ≤ 0.3 | 0.1 |
| Curesidual element | ≤ 0.25 | 0.1 |
| Fe | balance |
What surface finishes work on 35#?
Not anodizable. Use black oxide, phosphating, zinc or hard chrome plating, or paint; oil machined parts before shipment to prevent rust.
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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
How much does 35# cost?
35# 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.
35# — frequently asked
What is 35# used for?
35# is typically used for shafts, industrial bolts and crankshafts. In short: medium-carbon Chinese plate.
What is the yield strength of 35#?
35# has a typical yield strength of 330 MPa (47.9 ksi) and a tensile strength of 560 MPa (81.2 ksi) — weaker than 78% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 35# easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machinability is best in the normalized or quenched-and-tempered condition, at 60–70 % of AISI 1212; annealed material tends to smear and burr. Work in the 170–210 HB range with generous coolant.
Can 35# be welded?
Yes — weldability is rated good (55/100). At C ≈ 0.36 % weldability is restricted: preheat heavy sections to 100–200 °C, use low-hydrogen electrodes or ER70S-6 wire, and stress relieve at 600–650 °C after welding to prevent cold cracking.
What surface finishes work on 35#?
Not anodizable. Use black oxide, phosphating, zinc or hard chrome plating, or paint; oil machined parts before shipment to prevent rust.
Can 35# be formed, bent or molded?
Hot forge at 1150–850 °C and normalize after forging. Cold bend radii should be at least 2t, and cold-drawn stock is best stress-relief annealed before bending.
What is the maximum service temperature of 35#?
35# 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 35#-HR and 35#-CD?
HR is the default condition — take as-rolled bar or plate as the standard stock for machining, forging blanks or low-to-medium load structural parts at 330 MPa yield and 160 HB. CD: use cold drawn bar for tight dimensional accuracy, good surface finish and raised strength in no-machining shafts, pins and screw-machine parts; ductility and residual stress are the limits. Yield strength is 330 MPa in HR versus 520 MPa in CD.
How much does 35# cost?
35# 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.
Can FabDigit make parts in 35#?
Yes — 35# is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASM Handbook Vol.1: Properties and Selection: Irons, Steels (1035/1035H) — ASM International (1990)
- Machinery's Handbook, 31st ed. (machinability ratings) — Industrial Press (2020)
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.