Shear Pin Replacement

I discovered after breaking a pin how difficult it is to get a prompt replacement. I have a BushHog brand post hole digger that requires an odd tapered shear pin that is threaded on the tapper end. You don't walk into your standard hardware store and find that pin. In fact I called all of the tractor dealer and farm supply companies within 50 miles to find out that none of them stock shear pins (what a surprise and disappointment).

In the end I found out that not only did I have to order them through a tractor dealer but the shear pins would cost about $12 (a piece!!!!) not including shipping. Also, it would take a week to get them delivered (what a crock!!!). In the end I did order three pins just in case I ran into this problem again.

Since I didn't want to wait a week I decided that temporarily I would "manufacture" my own shear pin. I went down to HomeDepot and pick up a standard #2 steel bolt (#2 is the correct hardness) and with a grinder tapered the end as appropriate (to get it to go into the hole on the post hole digger). Since I didn't have threads to put a nut on it I just used electrial tape to wrap around it to keep it in place.

One year later my "manufactured" pin is still in the post hole digger and my spare "real" shear pins are sitting in the garage in a little plastic baggie.

Just so you know here are some of the most popular bolt grades (you want #2 so that it can "shear" if needed).

Steel grade 2
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Zinc plated low carbon steel. Best for general hardware use where high strength is not required.

Steel grade 5
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Made from medium carbon steel, tempered and zinc plated. Best for automotive use and other areas where higher strength is desired. Steel grade 8
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Made from medium carbon alloy steel, tempered and yellow zinc plated. Best suited for applications where high strength and hardness is required.