Parallel Dowel Pins
ISO 2338
Precision Alignment & Location Pins for Engineering Assemblies
Manufacturer & Exporter: Super Industries India
1. Introduction to ISO 2338

ISO 2338 specifies parallel dowel pins used primarily for:
- Accurate positioning
- Repeatable alignment
- Shear load transmission
Unlike bolts or screws, dowel pins are not fastening elements; they are precision locating components used to maintain exact positional relationships between parts.
Super Industries
Global Manufacturer of Heavy & Custom Engineered Fasteners & Flanges
2. Role of Dowel Pins in Engineering Design
ISO 2338 dowel pins ensure:
- Exact component alignment
- Repeatable assembly & disassembly
- Reduced reliance on fasteners for positioning
They are critical in:
- Tooling
- Molds & dies
- Machine assemblies
- Automotive fixtures
3. ISO 2338 vs Fastening Pins
| Feature | ISO 2338 Dowel Pin | Bolt / Screw |
|---|---|---|
| Function | Alignment | Clamping |
| Thread | None | Present |
| Tolerance | Very tight | Moderate |
| Load type | Shear & location | Tension |
4. Dimensional Characteristics
- Diameter range: 1 mm to 50 mm
- Length range: 4 mm to 200 mm
- Cylindrical, straight profile
- Chamfered or rounded ends (depending on type)
5. Tolerance Classes

ISO 2338 typically uses:
- m6 tolerance (interference fit)
- h8 tolerance (sliding fit)
Selection depends on:
- Assembly method
- Load conditions
- Frequency of disassembly
6. Fit Types Explained
Interference Fit (Press Fit)
- Permanent positioning
- High vibration resistance
Transition Fit
- Semi-permanent assemblies
Sliding Fit
- Easy removal
- Temporary alignment
7. Materials Used
Super Industries India supplies ISO 2338 pins in:
- Carbon steel
- Alloy steel
- Stainless steel (AISI 304 / 316)
- Hardened & ground steel
8. Heat Treatment & Hardness
Typical hardness:
- 58–62 HRC (hardened dowel pins)
Benefits:
- Wear resistance
- Dimensional stability
- Long service life
9. Surface Finish Options
- Ground finish (standard)
- Black oxide
- Zinc plated
- Stainless natural
Ground finish ensures:
- Tight tolerances
- Smooth insertion
- Accurate alignment
10. Manufacturing Process

- Cold drawing / turning
- Precision grinding
- Heat treatment
- Surface finishing
- Final inspection
11. Inspection & Quality Control
- Diameter measurement (micron-level)
- Straightness testing
- Hardness testing
- Surface roughness checks
12. Engineering Applications
ISO 2338 dowel pins are used in:
- Injection molds
- Press tools
- Gear housings
- Engine blocks
- CNC fixtures
- Robotic arms
13. Advantages of ISO 2338 Pins
✔ High positional accuracy
✔ Excellent shear strength
✔ Reusability
✔ Minimal wear
14. Design Guidelines for Engineers
- Drill hole tolerance must match pin tolerance
- Avoid hammering hardened pins
- Use extraction holes for maintenance
- Combine with bolts for clamping
15. Common Design Mistakes
❌ Using dowel pins for tensile load
❌ Improper hole tolerance
❌ Misalignment during insertion
16. ISO 2338 vs DIN 7 / DIN 6325
| Standard | Status | Notes |
|---|---|---|
| DIN 7 | Legacy | Replaced |
| DIN 6325 | Similar | Common equivalent |
| ISO 2338 | International | Preferred |
17. Export & OEM Supply

Super Industries India provides:
- Bulk dowel pin supply
- OEM-custom lengths
- Export-grade packaging
- Batch traceability
18. Custom Manufacturing Capabilities
- Special lengths
- Non-standard tolerances
- Corrosion-resistant materials
- Application-specific hardness
19. Industries Served
- Automotive
- Heavy engineering
- Machine tools
- Power plants
- Aerospace fixtures
20. Conclusion
ISO 2338 dowel pins are critical precision components that ensure mechanical accuracy, alignment, and repeatability in complex assemblies.
Super Industries India manufactures ISO 2338 dowel pins meeting international quality expectations for global OEMs.
