How to Select the Perfect Dowel Pins
Sizing Your Dowel Pins
Dowel pin dimensions are determined by two key metrics: outer diameter (O.D.) and length.
Outer Diameter (O.D.): Ranges from 0.04 to 0.47 inches (1 to 12 mm)
Length: Available from 0.24 to 3.14 inches (6 to 80 mm)
*Tailor Made is available
Fit and Tolerance
Decide on the O.D. based on the fit required for your application:
Press Fit: These pins are slightly oversized for a tight fit, ideal for precision assemblies where alignment is critical.
Slip Fit: Designed for easy installation and removal without tools, perfect for self-locating assemblies.
End Styles
We provide two distinct end styles for our dowel pins:
Chamfered End: A slight taper that aids in guiding the pin into the hole.
Radius End: Available for metric sizes, this rounded end prevents damage during installation.
Standards Compliance (HEADWAY dowel pins adhere to several standards)
① American dowel pin standards, defined by the American National Standards Institute (ANSI) under B18.8.2, consist of two diameter series:
- Standard Series: The diameter is +0.0002 inches above the nominal diameter, intended for initial installations.
- Oversize Series: The diameter is +0.001 inches above the nominal diameter, designed for replacement applications.
The lengths of ANSI dowel pins have a tolerance of ±0.010 inches and are available in the following increments:
- 1/16-inch increments up to 3/8 inches
- 1/8-inch increments from 3/8 inches to 1 inch
- 1/4-inch increments from 1 inch to 2 inches
- 1/2-inch increments for lengths greater than 2 1/2 inches
- The length tolerance remains ±0.010 inches.
② European dowel pin standards set by the International Organization for Standardization (ISO) outline the specifications for steel dowel pins ranging from 1 mm to 20 mm, inclusive.
The ISO 8734 standard for dowel pins is currently aligned with DIN EN 28734, a standard established by the German Institute for Standardization.
Both ANSI and DIN are part of the ISO, which is a global non-governmental organization.
③ Military dowel pin standards are defined by Mil. Spec. NASM16555 (formerly MS16555), which specifies straight, headless pins with a diameter that is +0.0002 inches over the nominal size.
Additionally, Mil-P-21143/2 outlines undersize dowel pins with a basic diameter of -0.0002 inches under nominal size for straight, headless pins made from CRES 303.These military specifications are implemented for components used in applications within U.S. Military Departments and Defense Agencies to streamline the inventory of items in the military supply system.
④ Japan dowel pin standards are implemented in accordance with the relevant provisions of the Industrial Standardization Law and the standards set forth by the Japan Die & Mold Industry Association (JDMA) / Japan Standards Association (JSA).
※Dowel pins are produced according to various national and international standards, each featuring minor variations in chamfer shapes, tolerances, and the materials offered.
- DIN 6325—Full Hardened to Hrc 58-62 & Ground to m6 tolerance Steel.
- ISO 2338 (1998)— Mild Steel, Stainless Steel 303 or Stainless Steel 316 in m6 or h8 tolerance.
- ISO 8734—Type A is full hardened steel, ground to m6 tolerance. Type B is case hardened steel, ground to m6 tolerance. Type C is hardened, martensitic stainless steel. This standard looks identical to ISO 2338.
- The ISO 8734 standard for dowel pins is now equivalent to DIN EN 28734, a standard set by the German Institute for Standardization.
- DIN 7—Mild Steel, Stainless Steel 303 or Stainless Steel 316 in m6 or h8 tolerance.
- DIN 7979D—Extractable Dowel, full Hardened to Hrc 58-62 & Ground to m6 tolerance.
- BS 1804 Part 1—Imperial solid dowels in steel, unhardened or case-hardened depending on diameter.
- BS 1804 Part 2—Metric solid dowels, available to order
- BS 1804 Part 3, Type B—Extractable Dowels and Taper Pins
- BS 7055—Equivalent to ISO 8734
- IS0 8733—Equivalent to DIN 7979A (unhardened)
- ISO 8735—Equivalent to DIN 7979D (hardened)
Material Choices
Our dowel pins come in three types of materials:
- 304 Stainless Steel: Strong and corrosion-resistant, suitable for applications where contamination is a concern.
- 440 Stainless Steel: Hardened for enhanced durability, ideal for demanding applications.
- Carbon Steel: Hardened for high resistance to deformation, making it perfect for rigorous environments.
Hardened vs. Soft Steel
Hardened steel dowel pins are designed to resist deformation more effectively. This is particularly crucial in the following situations:
- When your application requires slightly oversized dowel pins, as the installation process might deform non-hardened steel.
- When your assembly incorporates various types of fasteners, since hardened steel dowel pins enhance the strength of the assembly when used as pivot points or for aligning other components.
- Hard dowel pins are manufactured from 400 series stainless steel, which allows for hardening. In contrast, soft dowel pins are made from 300 series stainless steel, which cannot undergo heat treatment to achieve greater hardness.
Non-hardened steel dowel pins provide enhanced corrosion resistance, making them ideal for use in environments that are prone to corrosion, such as:
- Coastal or marine outdoor areas exposed to salt, humidity, rainfall, and atmospheric pollutants.
- Factories or plants that deal with airborne contaminants like industrial gases and dust.
- Agricultural or rural outdoor environments where there is exposure to nitrates, ammonia, and diesel fuel.
- Industries such as mining, mineral processing, and oil and gas, where equipment is often underground or in contact with soil.
- Water and wastewater treatment facilities, desalination plants, and the food and beverage sector, where equipment comes into contact with water.
Explore Our Dowel Pins
Discover our extensive range of dowel pins, filterable by style, material, and diameter. Contact Us!
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