Solid Pins

Solid Pins are straight, cylindrical, relatively inflexible press-fit pins. Available with or without a head, they are commonly used to locate components in a fixed position, to maintain alignment, or to act as axles, pivots or hinges.

SPIROL’s standard Solid Pins include Straight Pins, Knurled Pins, and Barbed Pins in diameters ranging from 2mm / .078” (5/64”) up to 6mm / .250” (1/4”). Standard materials include low carbon steel and nickel stainless steel.

straight pins
Straight Pins
Offered with or without a head, Straight Pins are distinguished by their uniformity. The chamfered ends are more consistent than tumbled edges—making installation with automatic assembly equipment more reliable. Straight Pins are retained by compressing the host, not the pin. They are suitable for use in plastics for press-fit applications limited to those cases where the host material can withstand compression in the order of 0.05mm – 0.08mm (.002” – .003”). These pins are often used to replace ground dowels in applications that do not require the tight tolerances of a ground dowel.

SPIROL offers two different types of Straight Pins: The Series DP100 Straight Pin and the Series FH100 Headed Pin.

knurled pins
Knurled Pins
Offered with or without a head, Knurled Pins are available with either straight or helical knurls. Unlike a Straight Pin where retention is provided by the uniform interference between the pin and hole, knurled pins are designed to cut into the host. The displacement of the host material into the valleys of the knurls yields more frictional contact area between the pin and hold this resulting in higher retention. With Helical Knurled Pins, a 30º knurl causes the pin to rotate as it enters the hole creating even more surface contact with the host. This results in higher frictional forces, greater engagement and improved resistance to back out.

Straight knurls have lower insertion forces than helical knurls, offer resistance to turning within the assembly, but provide limited retention when axially loaded. Therefore, straight knurls are often recommended when the pin is used to transmit torque such as when used as an axle to rotate a wheel. Helical knurls provide both resistance to torque and push out when axially loaded.

SPIROL Standard Knurled Pins include: The Series KP200 Straight Knurled Pin, Series KP300 Helical Knurled Pin, the headed Series HP200 Headed Straight Knurled Pin and the Series HP300 Headed Helical Knurled Pin.

barbed pin
Barbed Pins
Offered with a head, SPIROL’s HP400 Headed Barbed Pins were created specifically for use in flexible plastics where optimum resistance to axial force is desired. The raised barbs are angled backwards, opposite the direction of insertion. After installation, the plastic will backfill into the area around the barbs resulting in maximum retention. Barbs are not appropriate for brittle plastics or those containing high percentages of fillers. As barbs are a radial feature, they do not resist rotation of two components relative to one another. For this requirement, a straight or helical knurl should be used. All Barbed Pins are provided with a generous pilot to facilitate alignment with the hole and ease installation.

Additional Information

Read The Difference Between Cold Headed and Machined Solid Pins and other White Papers on Press Fit Solid Pins.

Review our Application Stories for how SPIROL Engineers and Products have helped provide quality and cost saving solutions for fastening and joining problems.

SPIROL designs and builds Pin Installation Equipment with fixtures for your Solid Pin applications.

Request A Quote







    Files extensions allowed: 3ds, asm, doc, docx, dwf, dwfx, dwg, dxf, gif, iges, igs, ipt, jpg, mov, mp4, mpg, pdf, png, ppt, pptx, prt, sldam, sldasm, slddrw, sldprt, step, stl, stp, tif, xls, xlsx, x_b, x_t



    Current Page Title:
    Current Page URL:

    Need help finding the right solution?

    SPIROL offers complimentary Application Engineering support. We will assist on new designs as well as help resolve issues, and recommend cost savings on existing designs.