Machining-Friendly Steel · Free-Machining Steel
Steel SUM24L
Steel SUM24L is a machining-friendly steel steel — leaded free-machining bar. Typical values: 420 MPa yield, 7.85 g/cm³, rated to 400 °C. Available for CNC machining at FabDigit.
Properties
Typical room-temperature values in the HR (hot Rolled) condition. Metric first, imperial in gray. The bars show where SUM24L sits against the other 317 steel grades in the catalog.
Datasheet
| Yield strength | 420 MPa61 ksi |
|---|---|
| Tensile strength | 540 MPa78 ksi |
| Hardness | 160 HB |
| Density | 7.85 g/cm³0.284 lb/in³ |
| Specific strength (yield ÷ density) | 54 |
| Min service temp | -50 °C-58 °F |
| Max service temp | 400 °C752 °F |
| Electrical conductivity | 11 % IACS6.4 MS/m |
| Machinability | Excellent92 / 100 |
| Weldability | Poor20 / 100 |
| Formability | Fair40 / 100 |
| ISO 513 machining group | P |
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Against other steel grades
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. SUM24L is highlighted; hover a dot for its name, or open the interactive family chart.
Manufacturability
The process limits FabDigit's quote engine applies to SUM24L. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Excellent92 / 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 |
Conditions and tempers
How SUM24L is supplied and what each state is for. The default is what FabDigit quotes unless your drawing says otherwise.
| Condition | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
HRDefault Hot Rolled (HR) | Cheapest steel, looser tolerance — welded frames, base plates | — | — | — | — |
CR Cold Rolled (CR) | Smoother and more precise than hot rolled — brackets, enclosures | — | — | — | — |
CD Cold Drawn (CD) | Precision bar with finished OD — shafts, pins, less machining | — | — | — | — |
Annealed Temper | Softest supply state — for forming, or when you heat-treat after machining | — | — | — | — |
Heat treatment and post-processing
Operations FabDigit's suppliers routinely run on SUM24L, ranked by how often they make sense for this grade.
Heat treatment
| Quench & Temperrecommended | Achieve target hardness with controlled toughness28–55 HRC |
|---|---|
| Full Anneal | Restore ductility; relieve residual stress; coarsen grain |
| Stress Relief | Reduce residual stress without changing structure |
| Normalize | Refine grain; reset prior cold-work |
| Induction Hardening | Local surface hardening via induction50–62 HRC |
| Process Anneal | Reduce stress between cold-work steps |
| Flame Hardening | Local surface hardening via direct flame50–60 HRC |
| Case Harden (Carburize) | Diffuse C into surface; harden case to 60+ HRC58–64 HRC |
Post-processing
| Manual Deburr | Deburrstandard |
|---|---|
| Edge Break (0.5mm) | Deburr |
| Shot Peen | Blast |
| Glass Bead Blast | Blast |
| Laser Mark | Marking |
| CMM Inspection | Inspection |
| FAI Report | Inspection |
| Individual Bag | Packaging |
Surface finishes for SUM24L
Coatings and treatments compatible with steel on the processes SUM24L runs on. Pick them in the quote configurator or call them out on the drawing.
Plating
- Chrome Plating
- Copper Plating
- Electroless Nickel (EN)
- Gold Plating
- Hard Chrome Plating
- Hot-Dip Galvanizing
- Nickel Plating
- Silver Plating
- Tin Plating
- Zinc Plating
- Zinc-Flake (Dip-Spin) Coating
- Zinc-Nickel Plating
PVD Coating
- AlCrN
- AlTiN
- CrN
- DLC
- MoS2
- TiAlN
- TiB2
- TiCN
- TiN
- WC/C
- ZrN
Organic Coating
- Cerakote
- E-Coating
- Epoxy Coating
- Painting
- Powder Coating
- PTFE Coating
CVD Coating
- CVD Al2O3
- CVD TiCN
- CVD TiN
- Multilayer CVD
Marking / Decoration
- Chemical Etching
- Dot Peen Marking
- Electro-chemical Etching
- Ink Stamping
- Laser Marking
- Mechanical Engraving
- Steel Stamping
- Vibro Engraving / Scribing
Black / Phosphate
- Black Oxide
- Manganese Phosphate
- Zinc Phosphate
Thermal Spray
- HVOF Coating
- Plasma Spray
Equivalent designations
Standards and trade names that resolve to Steel SUM24L in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Other
- 12L14 equivalent (SUM24L)
Stock forms
Raw-material forms FabDigit sources SUM24L in.
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.