The most frequently asked questions about SLIC pins-Design Engineering

2021-12-08 09:03:26 By : Ms. Anny Yu

Pivot Point answers common questions about self-locking implanted split pins, from custom sizes to unit costs.

"SLIC" is the abbreviation of "Self-Locking Implanted Cotter". As the name suggests, the SLIC pin has a spring-loaded plunger and acts as an independent split pin.

Since being introduced to the market 15 years ago, millions of SLIC pins have been implemented in thousands of applications in various industries. When it comes to technical issues, we have all seen them. We have compiled a list of the most frequently asked questions about SLIC pins:

What are the common sizes? SLIC pins can be customized to any length, with common diameters ranging from 3/16 to 3/4 inches, including 6, 8, 10, and 12 mm.

Material? The SLIC plunger itself is made of 316 stainless steel, and the bottom spring is 302 stainless steel. The main body of the SLIC pin can be made of almost any material whose hardness does not exceed Rockwell 40C, including carbon steel, grade 5 and grade 8 equivalent materials, stainless steel, alloy steel, aluminum, etc. SLIC pins usually use cold-formed bodies, but more complex designs sometimes use machined bodies with threads, flats, taps, grooves, through holes, multiple plungers, and other features. Before the plunger is installed, almost any surface treatment can be applied to the SLIC pin at the pivot point.

What is the standard? The SLIC pin is not subject to any international standards. However, you can refer to most clevis pin standards (ASME B18.8.1, ISO2341, DIN 1444, SAE J493, etc...) to develop SLIC pins with industry standard clevis pin sizes/materials/surface treatments, but use The SLIC plunger replaces the hole for the split pin or the groove for the e-clip or retaining ring.

Isn't this like a spherical positioning pin? Although SLIC pins and spherical positioning pins look similar, there are many differences. Exhibit A shows the similarities and differences between these two labor-saving solutions:

How strong is the plunger? As with any fastening solution, the answer to this question depends on the specific application and the fastener itself. In a hole of the right size, the retention strength of the SLIC plunger is comparable to the corresponding opening or clamp of the pin of this size. Remember that the SLIC plunger, like many split pins and clamps, is not intended to be a load-bearing part of the assembly. These designs are only used to fix the pins themselves. We strongly encourage collaboration during the design phase so that we can help guide the design of your mating parts to maximize the performance and life of the SLIC plunger. In addition, Pivot Point encourages our customers to test SLIC pins in their applications. We are happy to customize samples for testing or find some similar sizes for quick fit check.

Can you make the plunger higher? Each SLIC plunger is designed to maximize the capture height of its designated pin diameter. When the SLIC plunger is depressed for flushing, no space is wasted in the pin to accommodate the higher plunger.

How to delete it? Many pins and fasteners are used in semi-permanent applications and only need to be removed for repairs or major product failures. In other applications, the pins may not need to be removed at all. Sometimes, pins need to be easily removed throughout the life of the product. The SLIC pin is usually suitable for any of the above situations. The spring-loaded plunger in the SLIC pin can be easily pressed with a finger or tool, and the pin can be removed. In applications where the plunger may be sandwiched between layers of material during removal, our "removable" plunger series has a rounded tip to help bridge small gaps (Figure B). The size of the gap that can be bridged depends on the size of the pin and the corresponding SLIC plunger.

Applications with large gaps/grooves may require pressing the plunger multiple times to pass through each layer during the entire removal process. Multi-diameter SLIC pins can simplify the disassembly of applications where the mating hole size can be offset-see Exhibit C.

Is there a removal tool? The bottom spring of the SLIC pin is customized to provide a strong holding force, but can be easily depressed with your fingers. Although tools are of course not necessary, in cases where a large number of pins need to be removed, tools can be used to depress the plunger for quick removal. Pivot Point is happy to design removal tools for your high-volume applications.

Cool product, but how expensive is it? The purchase price difference between the SLIC Pin and the clevis (or other solution) is not as large as most people expect. The automation of Pivot Point allows us to manufacture SLIC Pins at an amazingly affordable price. In addition, in most applications, the labor savings due to increased efficiency exceeds the initial cost difference. Actual tests show that SLIC Pin is at least 2-1/2 times faster than Hair Pin Cotters, which is relatively easy to install. (See Appendix D-Clock relationship between SLIC Pin installation and U-clip/hairpin installation). When converting to SLIC pins, more cumbersome assembly methods (such as nuts/bolts, extended cotter pins, and electronic clamps/retaining rings) can save more costs. When comparing SLIC with other assembly methods, the cost of incorrect installation of clips and openings is often overlooked. They may fall off later and cause problems throughout the life of the product. SLIC Pins eliminates this risk and creates more value through slower and less elegant methods.

Can you add a button to the SLIC Pin for easy removal? Although this concept is not impossible, adding an internal spindle reduces the amount of space inside the pin, so the plunger height needs to be greatly reduced to fully retract into the pin. Therefore, the pin will eventually have a catch height similar to a button ball lock pin. Balls are easier to use in this type of design because they roll along the internal main axis, which is why they are popular designs for this type of function in the industry. Compared with the button ball lock pin, the SLIC plunger button pin has almost no advantage.

How can I get some samples? Feel free to ask-Pivot Point is happy to provide samples for testing. We often make samples according to your specifications, or we can find similar sizes for quick sampling. Visit for more information.

Your email address will not be published. Required places have been marked *

Save my name, email, and website in this browser for the next time you comment.

View DE's November/December 2021 digital edition

Sponsored post