Steel SUM32
JIS SUM32
SUM32 is a resulfurized carbon free-machining steel comparable to AISI 1117, combining manganese sulfide chip control with enough carbon and manganese for case hardening.
Reference datasheet — SUM32 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 CD condition
SUM32 tempers and conditions
SUM32 is supplied in 6 conditions, soft to hard. CD is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled | Cheapest form for large-section parts that will be fully machined or subsequently heat treated. | 235 | 425 | 33 | 121 HB | — |
Solution annealed | Softest condition for heavy cold heading, deep boring or before carburizing. | 285 | 430 | 33 | 121 HB | 10.8 % IACS |
Normalized | Uniform fine grain and better toughness/consistency before machining or case hardening. | 303 | 467 | 33.5 | 121 HB | 10.5 % IACS |
Cold Drawn + Stress Relieved | Choose when parts must stay straight after asymmetric machining of cold-drawn bar. | 395 | 470 | 18 | 143 HB | 10.5 % IACS |
CDDefault Cold drawn | Standard stocked condition for screw-machine work: good size tolerance, straightness and chip control. | 415 | 485 | 15 | 143 HB | — |
Carburized, Quenched & Tempered | Use when the machined part needs a wear-resistant case (~0.3–1.0 mm) over a tough low-carbon core. | 420 | 640 | 15 | 60 HRC | — |
Supply forms, finishes and certifications
Ways SUM32 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
TGP | Turned, Ground & Polished bar | Surface finish |
What is SUM32?
SUM32 is a resulfurized carbon free-machining steel comparable to AISI 1117, combining manganese sulfide chip control with enough carbon and manganese for case hardening. It is used for gears, shafts and bushings that are carburized after turning, and is available cold-drawn, hot-rolled, annealed, normalized, stress-relieved, as TGP bar and carburized-and-quenched. Cold-drawn bar runs about 415 MPa yield, 485 MPa tensile, 15 % elongation and 143 HB, with a machinability rating of 85 (roughly 90 % of 1212). Weldability is marginal and there is no corrosion resistance; SUM31 (1108) is the softer option, SUM41 (1137) the stronger one. SUM32 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). SUM32 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 485 MPa (70.3 ksi) — weaker than 56% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi).
What is SUM32 used for?
- Gears
- Shafts
- Bushings
Advantages
- Easy to machine — 85/100, better than 98% of steel grades
- Conducts heat well — 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- High electrical conductivity — 10.5 % IACS, better than 89% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
SUM32 properties
Typical room-temperature values for SUM32-CD; bars are the position among steel grades.
Physical3
SUM32 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).
Mechanical13
SUM32 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 485 MPa (70.3 ksi) — weaker than 56% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SUM32 is rated for continuous service to 350°C (662 °F). It conducts heat at 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
SUM32 conducts electricity at 10.5 % IACS, better than 89% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of SUM32 takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
SUM32's machinability is excellent (85/100, better than 98% of steel grades); weldability fair (40/100); formability fair (40/100).
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. SUM32 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SUM32
Is SUM32 easy to machine?
Excellent — ~90 % of 1212; MnS breaks chips and lubricates the cutting edge, allowing high feeds on CNC lathes with standard carbide.
Can SUM32 be welded?
Marginal — high sulfur invites hot cracking and porosity; if unavoidable use low-hydrogen filler, preheat 100–150 °C and low heat input, and avoid highly restrained joints.
Can SUM32 be formed, bent or molded?
Only light cold bending/heading; sulfide stringers cut transverse ductility, so hot form above 900 °C for severe shapes.
SUM32 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 |
|---|---|---|
| CJIS G4804 free-cutting steel | 0.12 – 0.2 | 0.16 |
| MnAISI 1117 counterpart runs 1.00–1.30 | 0.6 – 1.1 | 0.9 |
| P | ≤ 0.04 | 0.03 |
| SMnS inclusions give the free-cutting behaviour | 0.1 – 0.2 | 0.15 |
| Sinot normally specified; usually low (rimmed/semi-killed practice) | ≤ 0.1 | 0.05 |
| Fe | balance |
What surface finishes work on SUM32?
No anodizing; protect with black oxide, zinc phosphate, zinc or electroless nickel plating — inclusions can leave micro-pits after polishing or plating.
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 SUM32 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- 1117
How much does SUM32 cost?
SUM32 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.
SUM32 — frequently asked
What is SUM32 used for?
SUM32 is typically used for gears, shafts and bushings. In short: case-hardenable free-cutting steel; about 90 % of 1212; better formability than SUM41.
What is the yield strength of SUM32?
SUM32 has a typical yield strength of 415 MPa (60.2 ksi) and a tensile strength of 485 MPa (70.3 ksi) — weaker than 56% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is SUM32 easy to machine?
Yes — machinability is rated excellent (85/100, better than 98% of steel grades). Excellent — ~90 % of 1212; MnS breaks chips and lubricates the cutting edge, allowing high feeds on CNC lathes with standard carbide.
Can SUM32 be welded?
With care — weldability is rated fair (40/100). Marginal — high sulfur invites hot cracking and porosity; if unavoidable use low-hydrogen filler, preheat 100–150 °C and low heat input, and avoid highly restrained joints.
What surface finishes work on SUM32?
No anodizing; protect with black oxide, zinc phosphate, zinc or electroless nickel plating — inclusions can leave micro-pits after polishing or plating.
Can SUM32 be formed, bent or molded?
Only light cold bending/heading; sulfide stringers cut transverse ductility, so hot form above 900 °C for severe shapes.
What is the maximum service temperature of SUM32?
SUM32 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.
What is the difference between SUM32-CD and SUM32-HR?
CD is the default condition — standard stocked condition for screw-machine work: good size tolerance, straightness and chip control. HR: cheapest form for large-section parts that will be fully machined or subsequently heat treated. Yield strength is 415 MPa in CD versus 235 MPa in HR.
How much does SUM32 cost?
SUM32 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
- JIS G 4804 Sulfur and sulfur-composite free-cutting steels — JSA (2019)
- ASTM A29/A29M Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
- SAE/AISI machinability ratings for carbon steels — SAE International (2017)
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.