White Papers

Since 1948, SPIROL has been providing technical expertise in fastening, joining and assembly to the world's leading manufacturers. Browse through these examples of our Solution Engineering White Papers.

WHITE PAPERS

Coiled Spring Pins: Coiled Spring Pins Offer a Unique Balance of Strength and Flexibility [+] [--]

Easily recognized by its unique 2¼ coil cross section, Coiled Pins are retained by radial tension when installed into the host component, and they are the only pins with uniform strength and flexibility after insertion.

To read more, click here.; How to Design Assemblies That Use Coiled Pins for Locating and Alignment [+] [--]

To achieve optimal alignment when using Coiled Pins, two primary design elements must be adhered to:
1) The hole diameters in the host and mating component must be correctly sized to achieve the desired interference and accuracy of alignment.
2) The engagement length of the Coiled Pin in the component providing primary retention must be no less than 60% of the pin’s overall length.

To read more, click here.; How to Design the Optimum Hinge [+] [--]

There are two primary types of hinges: 1) a free fit hinge has little to no friction or drag when the latch or handle is rotated. Hinge components are “free” to rotate independent of one another, and 2) a friction fit hinge requires interference to prevent free rotation of components relative to one another. Depending on design intent, resistance can vary from a slight drag to a value sufficient to maintain the fixed position of components anywhere in their full range of rotation. This White Paper provides essential design guidelines for Engineers to achieve optimum long-term performance of both types of hinges.

To read more, click here.; How to Properly Pin a Gear and Shaft Assembly [+] [--]

This informative White Paper provides essential design guidelines to achieve the maximum strength of a pinned system and prevent damage to the assembly. Design guidelines are provided for both 1) the shaft and hub, and 2) the pin.

To read more, click here.; How to Select the Proper Diameter and Duty of a Coiled Spring Pin [+] [--]

This White Paper provides the fundamental guidelines for determining the optimum balance between strength and flexibility of the Coiled Spring Pin that will result in the prolonged net life of the assembly.

Read the complete White Paper about selecting the proper diameter and duty of a Coiled Spring Pin.; The Impact of Clearance on the Shear Properties of Coiled Spring Pins [+] [--]

SPIROL has identified common design/manufacturing errors which reduce the strength of pinned joints. These features include, but are not limited to, counterbores, countersinks, and gaps between mating components. This White Paper quantifies the effects that clearance between the shear plane has on the strength of a pinned joint.

Read the complete White Paper here.; Why Pins Walk and How to Ensure that Doesn't Happen [+] [--]

Lateral movement of installed pins, commonly referred to as 'walking’, can occur with any pin in a dynamic application if proper design guidelines are not followed. This includes rigid Solid Pins as well as Slotted and Coiled Spring Pins. Although any kind of pin can walk, the causes may be different for each style. This White Paper will address common causes for lateral movement and offer design guidelines to avoid the condition.

Read more about Why Pins Walk and How to Ensure that Doesn't Happen.
Compression Limiters: How to Ensure Bolted Joint Integrity When Using a Compression Limiter in a Plastic Assembly [+] [--]

Compression Limiters are used to protect plastic components in bolted joints and maintain a threaded fastener’s clamp load by eliminating plastic creep. To function properly, bearing surface beneath the bolt’s head must extend over the Compression Limiter to contact the plastic component. This White Paper explores several methods to ensure sufficient bearing surface under the bolt’s head while considering the individual component cost, ease or complexity of assembly, and the overall cost of each configuration to determine which method is best suited for each particular application.

Read the complete White Paper on how to ensure bolted joint integrity when using a Compression Limiter in a plastic assembly.
Compression Limiters and Threaded Inserts: How To Properly Mate Compression Limiters and Threaded Inserts in Plastic Assemblies [+] [--]

In applications where the mating component is also plastic, a Compression Limiter is necessary to avoid the creep or stress relaxation in the mating component from reducing the frictional load in the threaded joint. This White Paper provides design guidelines on how to properly mate Compression Limiters and Threaded Inserts to ensure the desired joint integrity over the life of the product.

To read more, click here.
Cosmetic Pins: Measurement Techniques for the Inspection of Series 550 Coiled Pins for Cosmetic Cases [+] [--]

SPIROL® Series 550 Cosmetic Coiled Pins were designed specifically to be used as hinge pins in cosmetic cases. Considering the configuration of the pin and the fact that it is a functional spring, care must be taken when measuring the pins so as not to skew the measurement results. This White Paper will walk you through how to measure the key characteristics of a Series 550 Cosmetic Coiled Pin as well as recommend the proper measurement equipment.

To read more, click here.
Disc Springs: How Deflection Range Affects the Performance of Disc Springs [+] [--]

Deflection of Disc Springs has a major impact on the performance and life of Disc Springs in both static and dynamic applications. Designers need to consider factors affecting performance and life of the Disc Spring to maximize the potential of a Disc Spring in their design.

Read more about Disc Spring deflection.; How to Calculate the Estimated Fatigue Life of Disc Springs [+] [--]

Disc Springs are conically-shaped washers designed to be axially loaded. They can be used individually or assembled into stacks to achieve the desired force-deflection characteristic required for the application. Since deflection of a Disc Spring at a given load is predictable, it is possible to calculate force and stress levels within the Disc. This paper focuses on the use of Disc Springs and how to estimate fatigue life in dynamic situations.

Read more on How to Calculate the Estimated Fatigue Life of Disc Springs
Finishes and Coatings: Features and Benefits of ArmorGalv ® Thermal Zinc Diffusion [+] [--]

SPIROL is pleased to offer ArmorGalv®, a Thermal Zinc Diffusion coating, as a standard finish option for their engineered fasteners. This uniform deposition coating is poised to revolutionize the industrial fastener market with 1,000+ hours of corrosion resistance, no risk of hydrogen embrittlement, and no insignificant surfaces!

Download the ArmorGalv® White Paper.
Inserts for Plastics: How to Maintain Joint Integrity When Converting from Metal to Plastic [+] [--]

Inserts for Plastics allow designers to replace machined and cast metal components with plastic to achieve significant cost and weight savings without any loss of joint strength - even in demanding applications. Threaded Inserts can be installed with heat or ultrasonics, they can be molded-in, pressed-in, or tapped into the hole. The challenge is for Engineers to choose an Insert that meets the performance and assembly requirements of the application. This article describes how Inserts for Plastics work, and provides design guidelines for the plastic host components to ensure that the completed assembly meets the desired expectations.

To read more, click here.
Installation Equipment: Heat Versus Ultrasonic Installation [+] [--]

This informative document analyzes the differences between heat and ultrasonic installation of Threaded Inserts into plastic assemblies. In addition to detailing the advantages and disadvantages of each installation method, this White Paper also provides essential information as to how one can be sure that the Threaded Insert was installed properly into the assembly.

To access the White Paper, click here.; Vibratory Feeder Noise Reduction [+] [--]

The effects of noise can have damaging consequences and efforts should be made to minimize noise exposure. Reduction of noise produced by vibratory feeders is one area that can significantly reduce noise exposure in the workplace.

The SPIROL Series 2000 Vibratory Feeder is quieter than conventional vibratory feeders. Empirical data to support this claim was gathered by conducting comparison testing between a conventional square drive and a SPIROL Series 2000 drive. Measurements and analyses were performed by Noise Control Engineering (NCE) of Billerica, Massachusetts. The same bowl was used for testing on each drive. Noise readings were taken with an empty bowl, plastic bottle caps and metal coiled pins. Consistent feed rates were maintained between the Series 2000 and the square drive for both the caps and the pins.

Four measurements around each vibratory feeder were taken and averaged in order to compare the square drive to the Series 2000.

To read more, click here.
Shims: How to Control Shim Tooling Costs [+] [--]

SPIROL has several manufacturing methods that eliminate or greatly reduce your tooling expenditure.

Shim tooling costs are one of the quickest ways to drive a prototype or short-run production project over budget. SPIROL has several manufacturing methods that eliminate or greatly reduce your tooling expenditure. Whether your project is for prototype, short run or long term requirements, SPIROL has a solution to minimize your installed component costs by controlling tooling costs. This article describes some of SPIROL’s production technologies to help you determine which method is best for you.

To read more, click here.; The Advantages of Using Edge Bonded Shims [+] [--]

Laminated Shims have peelable layers of metal which are removed until the Shim has the proper thickness. They are built up from layers of precision gauge metal foil. Layers are bonded into a rigid structure that appear and function as a solid sheet or plate. In this document you will read about two types of Laminated Shims: Surface Bonded and Edge Bonded Shims, and how Edge Bonded Shims provide solutions to reducing assembly times, minimizing costs, and improving safety.

Read more on the use of Edge Bonded Shims.
Solid Pins: The Difference Between Cold Headed and Machined Solid Pins [+] [--]

The objective of this paper is to educate designers about the differences between cold heading and machining so that they understand how to design a Solid Pin that optimizes performance and reduces total manufactured cost of the assembly.

Read more about cold headed vs machined solid pins.
Solid Pins, Slotted Pins and Coiled Pins: How to Choose Fasteners that Maximize Assembly Life [+] [--]

An assembly can be held together many different ways. The challenge for the Design Engineer is to choose a method that provides the highest quality joint with integrity over time at the lowest manufacturing cost. For many applications, a self-retaining pin is the winning solution. The difficulty is selecting the proper pin with the appropriate strength and flexibility for the application. This Technical White Paper reviews the advantages and disadvantages of common types of pins, as well as provides guidelines as to when to use each type in certain applications.

To read more, click here.
Solid Pins, Slotted Pins, Coiled Pins and Spacers: Fastening Solutions for Medical Devices [+] [--]

Even though the application requirements do not justify it, fasteners used in medical devices are usually specified as extremely tightly toleranced parts. In addition, due to the unfamiliarity of the various fastener industry standards and associated manufacturing processes, Engineers frequently tie the hands of the fastener manufacturer into using high-cost manufacturing processes to meet the specifications.

This White Paper focuses entirely on what designers and manufacturers need to know, avoid and do when it comes to pinning and spacing requirements in medical devices.

To read more, click here.
Spring Pins: How to Maximize Retention of Spring Pins [+] [--]

When proper design guidelines are followed, companies can take advantage of the many benefits that Spring Pins offer. They significantly reduce the total cost of the assembly, lower insertion forces and improve the life of an assembly by absorbing shock and vibration. This White Paper walks through a handful of simple – but essential - design guidelines for Engineers to ensure assemblies have reliable robust joints with excellent retention.

To read more, click here.; Which Austenitic Stainless Steel Spring Pin is Best for Dynamic Loading? [+] [--]

Although there are many advantages to using Spring Pins, it is important to understand the design features between Slotted and Coiled Spring Pins - particularly for critical applications and those subjected to dynamic loading. This White Paper details the specific design differences between both Slotted Spring Pins and Coiled Spring Pins and explains which Spring Pin is best for dynamic loading.

Read more about Which Austenitic Stainless Steel Spring Pin is Best for Dynamic Loading.
Stainless Steel: Comparative Analysis of Stainless Steel and Carbon Steel Fasteners [+] [--]

Corrosion of stainless and carbon steel are very different. This paper will provide information regarding general attack or surface corrosion as this is often a primary consideration when selecting fastener material.

To read more, click here.; Type 316 Stainless Steel Comparison [+] [--]

The versatility of Coiled Spring Pins often times makes them the ideal fastener to meet the specific engineering and economic objectives of pinning applications. They are available in a wide variety of sizes, duties, finishes, and materials. Amongst the materials used to manufacture Coiled Spring Pins, stainless steel is often required for its high corrosion resistance. Coiled Spring Pins are most often manufactured from Type 302/304 and Type 420 stainless steel, but Type 316 is also available and is typically selected for its superior corrosion resistance. This paper takes a closer look at how Type 316 compares to Type 302/304, and discusses various applications and environments where it offers an advantage.

To read more, click here.