Forged Rocker Arms
A rocker arm transfers cam motion to the valve, reversing direction and multiplying force. It cycles thousands of times a minute for the engine's whole life.
Forged rocker arms transfer cam motion to engine valves, cycling thousands of times per minute. Forging delivers the stiffness-to-weight ratio needed to avoid adding valve train inertia, with hardened contact pads up to 58 HRC and pivot bores machined to ±0.02 mm.
- Materials
- EN8, EN19, 20MnCr5
- Pad hardness
- Up to 58 HRC
- Bore tolerance
- ±0.02 mm
- Weight range
- 0.1 kg – 3 kg
- Applications
- Diesel engines, industrial machinery
Forged Rocker Arms at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Pad hardness up to 58 HRC
- Pivot bores machined to ±0.02 mm
- Weight range 0.1 kg to 3 kg
- Forged for stiffness at low mass
High Cycle Count, Low Mass
The rocker arm must be stiff enough not to flex under valve spring load, yet light enough not to add inertia at high engine speed. Forging achieves that stiffness-to-weight ratio in a section that casting would need to make heavier.
- Stiffness without added mass
- Thousands of cycles per minute
- Hardened contact pad
- Bore concentricity to pivot
Contact Pad and Pivot Bore
The pad contacting the valve stem is hardened against wear; the pivot bore must stay round and concentric or the geometry shifts. Both are machined and verified rather than left as forged.
People also ask
What causes rocker arm failure?
Wear on the valve contact pad from inadequate hardness or lubrication, and fatigue cracking at the pivot boss where bending stress concentrates.
Why does rocker arm mass matter?
Valve train inertia limits engine speed and increases valve spring loads. A lighter rocker arm allows higher speeds and reduces wear throughout the valve train.
What weight range do you produce?
0.1 kg to 3 kg finished, covering diesel engine and industrial machinery applications.
Topics covered on this page
- rocker arm
- valve train
- cam follower
- pivot bore
- valve stem
- inertia
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
Why are rocker arms forged?
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They need high stiffness at low mass to avoid adding valve train inertia, which forging achieves in a lighter section than casting.
Is the contact pad hardened?
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Yes, typically up to 58 HRC against valve stem wear, while the body stays tough.
Do you machine pivot bores?
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Yes, to ±0.02 mm with concentricity verified against the drawing.