PA12 Rod — Diameters, Lengths & Tolerances
PA12 rod is a round extruded stock form produced from Polyamide 12 (Nylon 12). PA12's low moisture absorption and excellent dimensional stability set it apart from PA6 and PA66 rod — components maintain tighter tolerances in humid environments and do not require the moisture conditioning steps that other nylon grades often need. PA12 rod is selected for precision gears, fittings, bushings, and mechanical components where consistent dimensional behavior is essential.
At a glance:
- Diameter range: 0.25" to 6.0"
- Standard lengths: 4 ft and 8 ft
- OD tolerance: +0.000" / −0.015" (typical); tighter on request
- Material: Polyamide 12 (PA12, Nylon 12) — extruded
- Color: Natural (off-white/ivory or translucent)
Standard Diameter Table
PA12 rod is stocked in the following standard diameters:
| Diameter | Standard Lengths | Notes |
|---|---|---|
| 0.25" | 4 ft & 8 ft | Small precision components |
| 0.50" | 4 ft & 8 ft | Fittings, wear pins |
| 0.75" | 4 ft & 8 ft | Lightweight bearings |
| 1.00" | 4 ft & 8 ft | General machining stock |
| 1.50" | 4 ft & 8 ft | Structural and precision parts |
| 2.00" | 4 ft & 8 ft | Fluid system and automotive components |
| 3.00" | 4 ft | Larger precision machined parts |
| 4.00" | 4 ft | Heavy-section structural components |
Contact Ready Plastics for custom diameters or cut-to-length service.
Mechanical Properties
PA12's key differentiator is low moisture absorption, which underpins its dimensional stability advantage:
| Property | Notes |
|---|---|
| Moisture absorption | Low — maintains dimensions in humid environments better than PA6 or PA66 |
| Mechanical strength | Good — suitable for load-bearing machined components |
| Impact resistance | Good flexibility and impact energy absorption |
| Chemical resistance | Good resistance to fuels, oils, and many solvents |
| Dimensional stability | Excellent — maintains tight tolerances over time |
| Density | Slightly lower than PA6/PA66 |
| Flammability (UL 94) | HB |
Numeric property values are available in the PA12 material datasheet. Refer to current datasheet for engineering calculations.
PA12 is an extruded grade. Compare it to PA6 rod for cost-sensitive applications or PA66 rod for higher-temperature requirements.
Typical Applications
PA12 rod is specified for:
- Precision gears and bushings — stable dimensions support close running fits
- Fittings and fluid connectors — chemical and fuel resistance supports fluid system components
- Automotive under-hood components — good thermal performance and fuel/oil resistance
- Equipment housings and structural parts — consistent mechanical behavior over service life
- Precision machined components — preferred over PA6 where moisture-induced dimensional change is a concern
Machining PA12 Rod
PA12 machines cleanly and produces fine surface finishes with standard carbide tooling. Its lower moisture absorption means dimensional changes from humidity are minimal, reducing the need for stabilization conditioning that PA6 components often require. Use moderate cutting speeds, sharp tools, and light coolant if needed. PA12 produces consistent chip formation and is well-suited to high-precision turning and milling operations.
Related
- PA12 Material Line Card
- PA12 Sheet — flat plate for precision panels and structural parts
- PA12 Tube — hollow stock for precision sleeve applications