Slotted tension pins, also known as spring pins, are multi-purpose, non-threaded, versatile, and economical fasteners. These hollow cylinders have a unique, self-locking quality that simplifies design and reduces assembly and production costs, particularly since they can be installed in a single operation.
The benefits of slotted pins are myriad. They regularly function as fasteners, hinge pins, stop pins, assembly pins and in many other roles. They can be used in stampings, castings, forgings, sintered metals, hard rubber and plastics.
These are some of the reasons they are trusted worldwide in industries from agricultural to off-road, wind power, automotive, mining, railway, hydraulic, and material handling to name just a few.
They’re easy to install.
Slotted pins are designed to be compressed into a hole, using spring steel pressure to hold it in place. This puts less pressure on an application than solid pins, requiring lower installation force. They also do not require special tooling to install. They can be manually installed with a hammer and drift all the way up to using high-speed automatic feeds.
They’re reusable.
Slotted pins can be knocked out during disassembly, such as for maintenance or cleaning, then easily reinserted. Chamfered edges facilitate insertion without disrupting the hole diameter or tolerance in any way. Their longitudinal slit permits compression during insertion, giving them a unique, self-locking quality.
They’re economical.
In addition to being reusable, slotted pins also afford great “in place” cost savings, reducing the total cost of assembling a product. Since these pins don’t need to have an exacting tolerance, holes do not need to be reamed, which means hole prep time is reduced.
They can be installed in a single operation, further reducing assembly and production costs. Once installed, the pin applies continuous pressure on the sides of the hole wall. This allows them to accommodate wider hole tolerances, which results in reduced manufacturing costs of components.
They resist shock and vibration.
The pressure that these pins put on the inside of the hole also provides radial tension to prevent loosening created by vibration or shock.
In a hinge, joint, or pivot point, in applications ranging from small arms to agricultural equipment, solar power, and more, tension pins resist sliding when exposed to shock or vibrations. Once installed tension pins will stay in place naturally and won’t fall out.
They’re universally accepted.
Slotted pins are found in multiple applications across multiple industries, used in settings as diverse as airplanes and cosmetic cases. They can replace a wide variety of other, more costly products, including coil pins, taper pins and more.
If you need to increase shear strength, most sizes can be double pinned. They are easily designed into many applications.
They accept a variety of platings well.
Unlike a coil pin, which cannot be coated on the inside of the coil, slotted tension pins can be plated both inside and outside. This gives them more corrosion resistance in demanding applications.
They’re available with many customizations.
Tension pins are most commonly found in high carbon spring steel that is heat treated to achieve optimum shear strength in all standard parts. They are also available in work hardened 18-8 nickel chromium steel, 420 hardened stainless steel, and can be made with exotic alloys like 316 steel on request. Large diameter pins are available up to M50 (metric) and up to 7 inches long.
They can be manufactured with unique features, including flared or headed pins, circumferential bevels with slot edges or wave tips below the surrounding diameter, special slot designs, specially closed gaps, and designs created specifically for use in automatic feeds.
Vogelsang offers the largest selection of metric slotted pins, with pins ranging from M1 to M50 outer diameter, all the way up to 250mm in length.
These thru-hardened fasteners simplify product design, increase product reliability, and reduce production costs and rejection losses. Slotted pins are an extremely cost effective option to displace more expensive coil pins and can be designed to fulfill the most demanding applications.
If you’re interested in slotted tension pins for your application, Vogelsang has thousands of standard products in stock and ready for same day shipment. If you know the part you need, it’s easy to request a quote online. Or call us at (800) 526-2376 to speak to a product specialist.