Clevis pins are fasteners with a hinge-like form, as they're of cylindrical shape with a head on one end and some form of fastening mechanism on the other, though in some cases, securing the clevis pin isn't actually necessary.

Clevis pins are perfect for applications that often require a movable connection between linked parts and are particularly useful in situations in which the shank must rotate, such as securing a turnbuckle. There are several main types of cotter pins:

• Non-locking — Clevis pins aren't locking pins by design, but they do have a through-hole at the bottom of their shank that allows them to be secured in place via various locking pins, such as cotter pin, split pin, or a hairpin cotter.
• Self-locking — Self-locking clevis pins have a spring-loaded stainless-steel ball on the bottom instead of a perpendicular bore. This allows such pins to self-lock when in use and prevents their removal until the spring-loading mechanism gets actuated, usually via a button head.
• Threaded — Threaded clevis pins have a partially threaded body on one end and a formed head on the other. The threads on the shank also have a lip, which acts as a stop when threading the pin into the shackle. These shouldn't be confused with threaded bolts and vice versa. Normal, threaded bolts are designed to withstand tension loads and aren't intended to withstand shearing forces like clevis pins are.

It's also worth noting that clevis pins come in a variety of different sizes and materials, the former of which will be addressed in the later section of our guide. The materials used to produce standard clevis pins are usually made of zinc-plated alloy steels. Stainless steel clevis pins are also used in specific applications, but the high carbon steels are generally not used, as they're very brittle.

How to Read a Chart and Size Table for Clevis Pins

To be able to read a chart and size table for cotter pins, you must be familiar with different dimensions and measurements taken into consideration during cotter pin selection. This includes different diameters and measurements, as well as materials in some cases. But there are some things you should know before looking at the charts.

On most charts, all pin dimensions are expressed in inches unless stated otherwise, so if you're using a metric system, you might want to convert the measurement units. Under the assumption that you're using the Imperial system, head diameter and head height are average dimensions, rounded to the nearest 64th.

When it comes to hole size, the dimensions aren't in accordance with SAE or ASME standards, and these refer to the clevis pin's perpendicular bore and not the mounting hole size. Most charts will provide the appropriate cotter pin range for different clevis pin sizes.

How Do You Measure a Clevis Pin?

The best and more precise way to measure a clevis pin is by using a precision measurement tool, like a caliper.

Step 1: Measure the length — Using your caliper, measure the pin's entire length from the top of the head to the pin tip. To calculate your effective length or grip range, use a caliper to measure from the bottom of the head to the edge of the hole that is closest to the head.

Step 2: Measure the pin diameter — This can be done either by using a caliper or by using the bolt gauge. Bolt gauges have size-labeled diameter holes for measuring bolt diameter. Insert the bottom of the clevis pin's shank through the gauge's corresponding hole. Your pin should be tightly in place but be able to rotate freely in all directions, including vertically and counterclockwise.

Step 3: Measure the head — Your caliper should be slightly more open than the clevis pin head. Start tightening the prongs over the head as soon as you can. The diameter of the pinhead is the outcome. From the bottom of the head to the top, use your calipers. Your head is at this height.

Clevis Pin Chart and Size Table

Here's a standardized chart and size table for clevis pins. Please use the accompanying image for reference:

Nom-inal Size	S		D		H		C	A		P		L	T		E	K	Recom-mended Cotter Pin Nominal Size
	Shank Dia.		Head Dia.		Head Height		Head Cham-fer	Hole Dia.		Point Dia.		Pin Length	Head to Center of Hole		End to Center Ref	Head to Edge of Hole Ref
	Max	Min	Max	Min	Max	Min	±0.01	Max	Min	Max	Min	Basic	Max	Min	Basic	Min
3/16	0.186	0.181	0.320	0.300	0.070	0.050	0.020	0.088	0.073	0.150	0.140	0.580	0.504	0.484	0.090	0.440	1/16
1/4	0.248	0.243	0.380	0.360	0.100	0.080	0.030	0.088	0.073	0.210	0.200	0.770	0.692	0.672	0.090	0.628	1/16
5/16	0.311	0.306	0.440	0.42	0.100	0.080	0.030	0.119	0.104	0.260	0.25	0.94	0.832	0.812	0.12	0.752	3/32
3/8	0.373	0.368	0.510	0.490	0.130	0.110	0.030	0.119	0.104	0.330	0.320	1.060	0.958	0.938	0.120	0.878	3/32
7/16	0.436	0.431	0.570	0.550	0.160	0.140	0.040	0.119	0.104	0.390	0.380	1.190	1.082	1.062	0.120	1.002	3/32
1/2	0.496	0.491	0.630	0.610	0.160	0.140	0.040	0.151	0.136	0.440	0.430	1.360	1.223	1.203	0.150	1.127	1/8
5/8	0.621	0.616	0.820	0.800	0.210	0.190	0.060	0.151	0.136	0.560	0.550	1.610	1.473	1.453	0.150	1.377	1/8
3/4	0.746	0.741	0.940	0.920	0.260	0.240	0.070	0.182	0.167	0.680	0.670	1.910	1.739	1.719	0.180	1.628	5/32
7/8	0.871	0.866	1.040	1.020	0.320	0.300	0.090	0.182	0.167	0.800	0.790	2.160	1.989	1.969	0.180	1.878	5/32
1	0.996	0.991	1.190	1.170	0.350	0.330	0.100	1.820	0.167	0.930	0.920	2.410	2.239	2.219	0.180	2.128	5/32

 

Summary

Clevis pins come in a variety of sizes, and knowing how to read a chart and size table can help you make an informed decision during the clevis pin selection process. If you're interested, you can view clevis pins here and learn more on Reid Supply's website.

 

Our Team Can Help You Find The Right Parts. Call (800) 253-0421
or email us at sales@reidsupply.com

Need a FREE CAD Download With Data Sheets?
REGISTER HERE