Primary process: Impression-die Forging. The full route, materials, tolerances and design tips for a connecting rod, with an indicative cost.
Impression-die ForgingPrimary process
Bulk formingFamily
8Route steps
+/-0.3mmTypical tol.
A connecting rod is primarily made by Impression-die Forging. Impression-die (closed-die) forging squeezes hot metal into a shaped die cavity so the grain follows the form. It gives high strength and good repeatability. Below is the full route to make a connecting rod, the materials it suits, the tolerances to expect and the main design points. The route is free, from the finder.
Step by step
How a connecting rod is made
The usual route, raw material to finished part. The amber step is where the connecting rod gets its basic shape.
Material
Cut billet or bar stock to size for the connecting rod.
Heating
Heat the billet to forging temperature so the metal flows.
Impression-die Forging
Force the metal to shape between the dies: the grain follows the form and gives the connecting rod its strength.
Tooling High (dies) Tolerance ±0.25 to 1mm Lead 8 to 20 weeks
Trimming
Trim the flash and pierce any webs the dies leave behind.
Heat treatment
Normalise, quench and temper to the final mechanical properties.
Tooling n/a Tolerance can distort Lead days
Machining
Machine the bearing surfaces, threads and precise features to tolerance.
Tooling None Tolerance ±0.125mm, to ±0.025mm Lead 1 to 10 days
Shot peening
Peen the fatigue-critical areas to raise service life.
Tooling Low Tolerance minimal Lead days
Inspection
Dimensional check plus crack detection on safety-critical parts.
Need the real cost for a connecting rod? The free route above is yours. Unlock the full dossier to quote and source it.
Where this process typically lands. Tighter is possible with extra operations like grinding, at higher cost.
Materials
Materials for a connecting rod
Grade
Why it suits this
AISI 4140
Good strength + toughness, easy to heat treat
AISI 4340
Higher strength + fatigue, deeper hardenability
36MnVS4 (microalloyed)
Air-cooled, skips separate quench+temper
Design
Design tips
General pointers. The full design-for-manufacturing list for a connecting rod is in the dossier.
Big-end bore held tighter than the bearing needs.Open to the real fit class.
Sharp fillet at the shank-to-end transition.Add a generous radius.
Cost
What a connecting rod should cost
Example ranges for a ~0.4kg automotive-type rod. Die cost TRY/USD 6k to 20k is spread across volume; it is why part one is expensive.
PER-PART COST vs VOLUME
Per-part cost drops as volume spreads tooling and setup over more parts. The exact figures for a connecting rod at your volume, in your currency, are in the dossier.
MODEL EST.
$180 to 420per part at 1 off
A rough ballpark only. The dossier gives should-cost at your exact volume and currency, with the full breakdown.
GET THE FULL DOSSIER
Everything you need to quote and source it
The free route above is yours. To actually put a number on a connecting rod and buy it well:
Should-cost at your exact volume in 12 currencies, with the material, processing, tooling and overhead breakdown
Who to source from, typical MOQ and lead time, and the exact RFQ checklist to send
A quote checker that tells you if a supplier quote is fair, and the red flags to watch
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A connecting rod is primarily made by impression-die forging. The route is: Material; Heating; Impression-die Forging; Trimming; Heat treatment; Machining; Shot peening; Inspection.
What does a connecting rod cost?
It depends on size, tolerance and volume. As a rough ballpark it starts around $180 to 420 per part at 1 off and falls with quantity. The dossier gives should-cost at your exact volume and currency. A model estimate, not a quote.
What material is a connecting rod made from?
Common choices are AISI 4140; AISI 4340; 36MnVS4 (microalloyed).
What is the main process for a connecting rod?
Impression-die Forging. Safety- and fatigue-critical parts in volume, such as connecting rods, crankshafts and hand tools.
See the exact route and should-cost for your part
The free finder maps your part to its process and full route. Pro adds should-cost at your volume, sourcing and an RFQ draft.
