Hardened Carbon Steel Dowel Pin Cylindrical Parallel Pin (DIN 6325 / ISO 8734)

The Hardened Carbon Steel Dowel Pin (commonly referred to as a parallel pin, cylindrical locating pin, steel alignment pin, precision ground dowel, or DIN 6325 / ISO 8734 fastener) is a solid, unthreaded cylindrical mechanical fastener engineered to hold machine components in precise alignment under heavy shear loads. Featuring chamfered lead-in ends at both extremities to facilitate smooth insertion into reamed holes, dowel pins absorb side-to-side shear forces and keep mating machine housings, die sets, and gearboxes perfectly registered. Manufactured from carbon and alloy steel (45# / GCr15 / 50CrV4), case-hardened to HRC 58–62, and precision centerless ground to m6 or h6 tolerances, our parallel dowel pins comply fully with global ISO standards.

Technical Specifications of Carbon Steel Dowel Pins

We supply both hardened parallel dowel pins (DIN 6325 / ISO 8734) and unhardened parallel pins (DIN 7 / ISO 2338). Precision centerless grinding delivers smooth surface roughness (Ra ≤ 0.8 µm) that prevents galling during press-fit mounting.

Precision Manufacturing, Heat Treatment, and Centerless Grinding Process

At our specialized manufacturing plant in Handan, China, parallel dowel pins undergo automated precision machining, heat treatment, centerless grinding, and anti-rust treatment:

• Precision Lathe Cutting & Chamfering: High-speed automatic CNC lathes shear carbon steel wire rods into exact lengths, forming smooth 15-to-20-degree lead-in chamfers on both ends.
• Controlled Atmosphere Quenching & Tempering: Continuous mesh-belt carburizing furnaces heat the pins to 850°C followed by oil quenching, establishing high surface and core hardness (HRC 58-62) to resist shear deformation.
• Multi-Pass Centerless Grinding: High-precision centerless grinders finish the outer cylindrical surface in multiple passes, achieving micron-level diameter tolerances (m6/h6) and super-finish mirror smoothness (Ra ≤ 0.8 µm).
• Anti-Corrosion Dip & Demagnetization: Ground dowel pins pass through demagnetization coils and anti-rust oil immersion baths to prevent oxidation during transit.

Key Engineering and Industrial Applications of Dowel Pins

Hardened parallel dowel pins are indispensable positioning elements across high-precision engineering sectors:

• Press Tools, Stamping Dies & Injection Molds: Aligning upper and lower die plates, core inserts, and stripper plates to prevent punch misalignment.
• Gearboxes, Motors & Industrial Reducers: Registering split cast-iron gear housing covers and bearing seats against internal shaft vibration.
• Automotive Engine & Transmission Assembly: Positioning engine blocks, cylinder heads, crankshaft main caps, and transmission cases.

Quality Control and Export Packaging for Parallel Dowel Pins

Handan YiHao Fastener enforces strict Quality Assurance (QA) standards for all overseas export orders. Testing procedures include 100% laser micrometer diameter inspection (micron accuracy), Rockwell hardness testing (HRC), surface roughness profilometer measurement, and salt spray validation.

All export items are packed in heavy-duty anti-rust oiled inner bags, placed in 25kg inner cartons, neatly stacked on ISPM 15 compliant fumigated wooden pallets, and wrapped in protective stretch film for safe ocean freight.