Precision reciprocating parts
Custom Piston and Pin Machining
Send Weldo your drawing, material, quantity and fit requirements for a piston and pin machining review with a project-specific quote.
- Metal and engineering-plastic options
- Precision bores, grooves and sliding fits
- Prototype to repeat production
- Drawing-based inspection support
Material selection
Pistons and Pins Matched to Your Operating Conditions
We machine piston bodies, piston pins, guide parts and sliding components for combustion, compression, fluid, automation and specialty-equipment applications.
| Part type | Common materials | Best suited for |
|---|---|---|
| High-load piston | 2618, 4032 forged aluminum | High-temperature or performance engine duty. |
| Steel piston / slider | 4140, 42CrMo4, 17-4PH, 304, 316L | Compression, hydraulic, pump and corrosion-resistant duty. |
| Engineering-plastic piston | PA, POM, PEEK, PTFE | Pneumatic, sealing, chemical and low-friction systems. |
| Piston pin | 9310, 8620, 52100, H13 | Fatigue-loaded and wear-critical pin joints. |
PA, POM, PEEK and PTFE are selected for fluid, sealing, guide and automation mechanisms. They are not substitutes for aluminum engine pistons in high-temperature combustion service.
Machining capability
Machining for Functional Piston Geometry
Hurco and Haas 5-axis CNC centers, turn-milling, grinding and wire EDM support functional piston features and matched sliding fits.
Hurco and Haas 5-Axis CNC
Crowns, reliefs, pin bosses and complex features in fewer setups.
Turn-Milling and Precision Boring
Diameters, grooves, bores and concentric fits.
Grinding and Wire EDM
Pins, hard running surfaces, narrow slots and special details.
Cleaning and Protection
Deburring, treatment coordination and assembly-ready packing.
| Feature | Quotation-stage range |
|---|---|
| Piston outside diameter | Ø20–300 mm |
| Piston pin outside diameter | Ø5–80 mm |
| Piston pin length | 15–250 mm |
| Precision bore diameter | Ø5–100 mm |
| Groove width | 0.8–5 mm |
Tolerance and verification
Control Critical Fits Before Assembly
Acceptance focuses on the measured fit, roundness, concentricity, surface condition and drawing-defined inspection positions—not only general profile dimensions.
| Critical feature | Reference capability |
|---|---|
| General dimensions | ±0.02 mm |
| Piston profile / outside diameter | ±0.01 mm |
| Pin bore / critical fit bore | ±0.005–0.01 mm* |
| Piston pin outside diameter | h6 optional |
| Pin surface finish | Ra 0.2–0.4 μm* |
*Quotation-stage reference. Final acceptance limits are confirmed by material, heat treatment, size, geometry, processing allowance and the approved inspection plan.
Wear and sliding performance
Finishes for Wear and Sliding Performance
Hard Anodizing
For aluminum ring grooves, pin bores and specified wear areas.
Low-Friction Coating
For piston skirts or designated sliding surfaces.
Nitriding or Carburizing
For steel pins and wear-resistant sliding components.
Precision Grinding
For pin diameters and critical running surfaces.
DLC or Phosphate
For high-load or boundary-lubrication applications.
Cleaning and Protection
Prevents contamination, corrosion and handling damage before assembly.
Project support
Start Your Piston Project
Send your drawing, material, quantity and critical-fit requirements for a machining review and quote.
Request a Quote →