F-0008 Iron-Carbon PM Steel: Properties, Applications, and Material Selection

What Is F-0008?

F-0008 is an iron-carbon sintered steel — the entry point of the PM steel grade family. Reading the MPIF designation:

• F — iron base
• 00 — no significant alloying additions (no copper, no nickel)
• 08 — nominal combined carbon content of 0.8% (working range typically 0.6–0.9%)

The material starts as plain iron powder blended with graphite. During sintering at 1,120–1,300°C, the graphite dissolves into the iron and transforms the microstructure from soft ferrite into a pearlitic/ferritic steel — without any melting, and without the cost of copper or nickel additions.

That simplicity is the point. F-0008 exists for parts that need "real steel" behavior — stiffness, moderate strength, machinability — at the lowest alloy cost in the PM system. It is the baseline against which the stronger alloyed grades (FC, FN, FL families) are measured.

Chemical Composition

Combined carbon — not admixed graphite — is what counts: graphite that fails to dissolve during sintering contributes nothing to strength and harms properties. Carbon control is the central processing issue for this grade; see Processing Notes below.

Mechanical Properties

As-Sintered (typical, density 6.4–6.8 g/cm³)

Typical industry values; actual properties depend on density, combined carbon level, and sintering practice. Higher density and full carbon dissolution push values toward the top of each range.

After Sizing or Higher-Density Processing

Sizing, coining, or higher compaction pressures raise density toward 7.0 g/cm³, with tensile strength typically reaching the 300–380 MPa range, depending on final density and carbon content.

Property character: F-0008 is a stiff, moderately strong, low-ductility steel. The pearlitic microstructure gives useful hardness and machinability, but elongation of 1–2% means it does not forgive impact or bending overloads. It is a material for parts that sit, locate, space, and carry modest steady loads — not for parts that flex or absorb shock.

Processing Notes

Compaction. Standard PM practice at 400–650 MPa covers most F-0008 parts. Without copper or nickel, the iron-graphite blend compresses well, and die life is good.

Sintering — carbon control is everything. The graphite must dissolve fully into the iron for the steel to reach its specified carbon level, but the furnace atmosphere can also remove carbon (decarburization) or add it (carburization) at the part surface. Endothermic gas or nitrogen-based atmospheres with controlled carbon potential are standard practice. Parts that run low on combined carbon come out soft and under-strength; the certificate of analysis for combined carbon is the key quality document for this grade.

Secondary operations. Sizing and coining for tolerance (IT5–IT6 class) and density; steam treatment for wear and corrosion resistance; machining for features the die cannot form. F-0008 machines cleanly in the pearlitic condition.

Heat treatment. F-0008 can be quench-hardened — its 0.8% carbon is near eutectoid — but hardenability is shallow without alloying, so through-hardening is limited to thin sections. For meaningful case depth or core hardness, an FN nickel steel is the correct starting point. See our heat treatment guide.

Typical Applications

F-0008 serves high-volume, low-stress structural parts across industries:

Appliances and consumer products

• Motor mounting brackets and spacers
• Structural washers, cams, and levers (low load)
• Latch and lock mechanism components

Automotive (non-safety-critical)

• Bearing seats and bushings carriers
• Spacers, stops, and adjustment cams
• Low-load sensor and actuator brackets

General industrial

• Guide plates and stops
• Pump and valve internal spacers
• Light-duty sprockets and timing pulleys (low torque)

The common thread: steady, modest loads; no meaningful impact; cost-sensitive volume production. For anything beyond that, see the upgrade paths below.

F-0008 vs Neighboring Grades

Material selection rarely means "Is F-0008 good?" — it means "Is F-0008 enough?" The decision table:

Rules of thumb:

• If the part is a magnetic core or must bend/rivet without cracking → FC-0000, not F-0008.
• If the part is a simple structural piece with gentle loads → F-0008 is the cost-optimal answer.
• If there is any gear tooth, spline, or meaningful cyclic load → start at FC-0205/FC-0208; the copper premium is small against the cost of a field failure.
• If heat treatment or impact resistance is specified → skip the FC family and go straight to an FN grade.

For cross-standard equivalents (MPIF / JIS / ISO), see the grade equivalents table. For the full steel family picture, see the sintered steel guide.

Design Considerations

Corrosion. F-0008 is plain carbon steel: it rusts. For humid or exposed service, specify steam treatment (which also improves wear), plating, or oil impregnation. This should be decided at quote stage, not after parts are made.

Wear surfaces. As-sintered F-0008 handles light sliding duty, and steam treatment extends it. Continuous or loaded wear surfaces belong on higher-carbon copper steels (FC-0208) or hardened FN grades.

Tolerances. IT7–IT8 as-sintered, IT5–IT6 after sizing — the same capability as the rest of our PM steel range. Because F-0008 contains no copper (which causes growth during sintering), its dimensional behavior in the furnace is predictable and shrinkage-based, which toolmakers appreciate.

Density specification. Properties track density; specify a minimum (e.g., ≥6.6 g/cm³) on the drawing rather than leaving it to assumption.

Economic note. F-0008's cost advantage over FC-0205 is the powder premium only — a few percent of part cost at typical sizes. If there is genuine uncertainty about the loads, the engineering-safe choice is usually to spend that few percent. We will say so in the DFM review if your drawing looks like it is on the boundary.

Source F-0008 Parts from SinterWorks

SinterWorks PM produces iron-carbon and alloyed PM steels on 36 presses from 6T to 400T, with controlled-atmosphere continuous sintering and combined-carbon verification on every grade. We are ISO 9001 certified and respond to drawings with DFM feedback — including an honest grade recommendation if F-0008 is on the boundary for your loads — within 24–48 hours.

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