Sintered structural part vs machined structural part vs die-cast structural part

The three most common manufacturing routes for a structural metal part. Pick by accuracy, strength, volume and part size.

Four powder metallurgy structural part families we make

Each cluster below groups the part geometries we run most often. Click through to the part card for typical dimensions, materials and tolerances.

Brackets, Housings & Flanges – The Mounting and Alignment Parts

Brackets, housings and flanges are the default PM structural parts. A bracket locates and mounts a component; a housing encloses a mechanism or a bearing; a flange connects two assemblies end-to-end. They share the same near-net-shape economics – press to shape, size the critical bores, ship. The value of PM here is the multiple bosses, steps and bores that would each be a separate machining operation if cut from bar stock.

From our quoting desk: the most common reason a bracket or housing RFQ gets returned is a thin wall at a bore. Below 1.5 mm the part cracks on ejection. We flag it in the DFM note and either thicken the wall or add a sizing step – either way, the customer knows before tooling, not after first article.

Part 01 Sintered bracket Fe-Cu, density 6.4-6.8 g/cm³, tensile 250-450 MPa. Two or three bosses with sized bores. Mounting plate for motors, pumps, sensors.

Part 02 Sintered housing Fe-Cu or Fe-Cu-Ni-Mo, density 6.6-7.0 g/cm³. Encloses a bearing or gear. Bearing bore sized to IT6. Common in power-tool and pump housings.

Part 03 Sintered flange and plate Fe-Cu, density 6.4-6.8 g/cm³. Flat flange with a bolt circle, or a plain sintered plate. Pressed flat, sized bolt holes. Connects pipe, shaft and motor assemblies.

Rings, Hubs & Counterweights – The Rotational and Balance Parts

Rings, hubs and counterweights are the simplest PM structural parts to make – mostly single-level pressings, so the tooling is the cheapest and the cycle is the fastest. A ring is a flat circular part with a bore; a hub carries a shaft or gear on a spline or keyway; a counterweight provides balance mass on a rotating assembly. Because they are flat or near-flat, they are also the highest-volume PM parts – the economics scale hard.

On material choice: for a counterweight, material cost is the whole game – we default to plain Fe-Cu at 6.6 g/cm³ because the customer is buying mass, not strength. For a hub that carries torque, we move to Fe-Cu-Ni-Mo at 7.0-7.2 g/cm³ and size the spline. The same geometry, two different materials, two different prices – that is where the DFM conversation saves money.

Part 04 Sintered ring Fe-Cu, density 6.4-6.8 g/cm³. Flat ring, OD 20-120 mm, bore sized to IT7. Spacer rings, thrust rings, retaining rings. Cheapest PM part to tool.

Part 05 Sintered hub Fe-Cu-Ni-Mo, density 6.8-7.2 g/cm³. Carries a shaft or gear on a spline, keyway or press bore. Sized spline to IT6. Gearbox and pulley hubs.

Part 06 Sintered counterweight Fe-Cu, density 6.4-6.8 g/cm³. Eccentric mass for motor balance, flywheel balance, washing-machine drum. Material cost is the driver – plain Fe-Cu.

Transmission & Drivetrain Parts – Synchronizer Rings, Clutch Hubs, Shift Forks, Ratchets

This cluster is the high-strength end of PM structural parts – automotive transmission and gearbox duty, where the part sees torque, impact and repeated engagement. The materials are low-alloy steel (Fe-Cu-Ni-Mo), the density is pushed to 6.8-7.2 g/cm³, and the surface is case-hardened to HRC 55-62. These are IATF 16949 programs with full PPAP.

Real failure mode we see: a shift fork fails at the fork-rail interface when the part is not case-hardened there. The shift fork slides on the rail thousands of times, so the sliding surface needs HRC 55-62 while the fork arms stay tough at HRC 25-35. We carbonitride selectively on the rail interface. Customers who skip this save 8% on the part and pay for it in warranty returns.

Part 07 Sintered synchronizer ring Fe-Cu-Ni-Mo, density 6.8-7.2 g/cm³, cone sized to IT6. Conical friction ring for gear engagement. Friction coating applied after sintering by a certified partner.

Part 08 Sintered clutch hub Fe-Cu-Ni-Mo, density 6.8-7.2 g/cm³, spline sized to IT6. Splined centre that clutch friction plates ride on. Case-hardened spline to HRC 55-62.

Part 09 Sintered shift fork Fe-Cu-Ni-Mo, density 6.8-7.2 g/cm³. Sliding fork for manual transmission. Rail interface case-hardened to HRC 55-62, arms stay HRC 25-35.

Part 10 Sintered ratchet and pawl Low-alloy steel, case-hardened teeth to HRC 55-62. Ratchet wheel + spring-loaded sintered pawl. Impact and wear duty – hand tools, winches, tensioners.

Levers, Latches, Valve Seats & Sintered Bushings – The Mechanism Parts

This cluster covers the mechanism parts – levers and latches for locks, appliances and small mechanisms, valve seats for engines, and the self-lubricating sintered bushings that get co-pressed into a structural part. These are smaller, high-cycle parts where wear resistance and dimensional stability matter more than raw tensile strength.

Part 11 Sintered lever Fe-Cu or Fe-Cu-Ni-Mo, density 6.4-7.0 g/cm³. Actuating arm with a pivot bore. Door handles, brake levers, appliance controls.

Part 12 Sintered latch Fe-Cu or 316L stainless, density 6.4-6.8 g/cm³. Locking catch with a strike face. Case-hardened strike face. Door locks, appliance latches.

Part 13 Sintered valve seat High-alloy sintered steel with copper infiltration, density 6.8-7.2 g/cm³. Engine valve seat insert. Heat and wear resistant. IATF 16949 program.

Part 14 Sintered bushing and bearing Oil-impregnated Cu-Sn 90/10, density 6.0-6.8 g/cm³, oil 12-18% vol. Co-pressed into a structural part or supplied loose. One MTC covers the assembly.

Capabilities for sintered structural parts

What you can ask for in your RFQ. All numbers are in-house, not subcontracted.

What we see in real RFQs: the most common reason a structural part drawing gets re-quoted is a feature that PM cannot press – an undercut, a reverse taper, or a thread. PM pressing only makes features in the direction of the press stroke, so undercuts and side holes need a secondary machining step. We flag every such feature in the DFM note with the added cost, so the customer can decide whether to redesign or pay for the secondary op.

Common HS code: 7326 (other articles of iron/steel) / 8483 (transmission parts) / 8708 (parts of motor vehicles). Confirm the exact line with your broker before the commercial invoice.

How a sintered structural part is made at JH PM

Six steps from your drawing to a sized, lot-level structural part. Same process we use for our automotive transmission parts and power-tool brackets – just a different die and a different secondary treatment.

On density targets: higher density costs more in press tonnage and cycle time, so we only push density where the part needs it. A bracket at 6.6 g/cm³ costs noticeably less than a clutch hub at 7.2 g/cm³, and both are correct for their duty. If your drawing calls for maximum density everywhere, expect to pay for it – we will tell you where you can drop the density without losing function.