In this article, we will look at the use of the drift and pritchel in the completing steps of the shoe punching process.
We’ll use the 5 City nail and 5/16×3/4″ barstock for the discussion. Figure 1 depicts the 5 City nail. Area A is the portion of the nail that will be projecting above the ground surface of the shoe. The forepunch displaces material for area B of the nail. Area B on a 5 City nail is 3/16″ long. After forepunching to this depth you have 1/8″ of material remaining to be punched through on a 5/16″ thick shoe.
1/8″ is a lot of material for a pritchel to remove efficiently. In order to get the most life out of your pritchel you should move 1/16″ of the remaining material with a drift. The drift is used to displace enough material for the area marked C in figure 1. This 1/16″ doesn’t seem like much but the relief that this gives is just enough to make pritcheling easier and more efficient. The drift has two important areas, the shank and the tip. The tip should be the exact size of the nail shank (area C, figure 1) and should be flat, not pyramid shaped like the forepunch. The dimension of the drift’s shank must be smaller than the forepunch to allow the drifting without making contact with the forepunch area. On smaller nails and on City nails this dimension is quite small, making this tool vulnerable to abuse and breakage. You should be very careful in the use and maintenance of the drift to get the proper results and reasonable lifespan for the tool.
The drift should only take one or two quick, light blows to move the 1/16″ of material. Do not bottom out or drive the drift into the anvil. To avoid excessive heat buildup in the tool do not stay in the hole any longer than absolutely necessary. You now have the shoe set up for pritcheling, the final step.
The pritchel’s sole purpose is to slug out a rectangular hole the exact size of the shank of the desired nail. The measurement of the shank area just below the head is the dimension the pritchel should be set for. In order to properly and precisely punch to the desired dimension you need to understand a few techniques.
1. The pritchel should work like a mini punch press.
It must shear the slug from the stock. In order to do this efficiently the stock must be relatively cold. This would be a black heat approximately 400-500 degrees. The blow must be sharp and straight. If the heat is higher (if you detect a red coloration in the steel) the material is too elastic and will not allow a clean shear. Instead it will drag material down with the tip leaving a burr on the backside. Numerous blows to the pritchel will also cause the same result. You need to make a single sharp straight blow to get maximum shearing effect.
2. The tip of the pritchel should be prepped to achieve the best results.
All pritchels come with a straight taper. As the pritchel is driven in the material, the taper forces the hole to expand. The farther you go in the bigger the hole becomes. The tip of the pritchel should be backed up to produce a tip the exact size of the desired nail, leaving a slight recess behind it. By setting your pritchel in this manner, the tip will shear out the slug and the pritchel will end up in the recessed area. The pritchel will not enlarge the hole and will now also be loose in the hole.
Backing It Up
Heat the tip of your pritchel and then draw the end out until it is smaller at the tip than the dimension of the nail you will be using. Place it back in the fire and take a short heat at the tip only. Do not heat it too much, a dull red is fine. Now start tapping (upsetting) the tip with the flat of your hammer. Continue to take short heats and work the tip until a small amount of the material is upset. Keep the pritchel tip going straight, don’t let it get crooked or bent. Take another short heat, set the upset area on the anvil edge and tap down on it, producing small flats. Check the size now with the nail shank. Another tap or two on the end should finish it for you. It should match the nail shank exactly. Set it aside and let it air cool.
With practice and attention to the details of the nail shank and pritchel you will learn how much to back up and how much to flatten to get the desired result. Setting and using your pritchel in this manner (along with using a good drift) will allow you to use your pritchel for more shoes with less need for adjustment.
This Tool Corner is from The Natural Angle Volume 1, Issue 3 – written by Roy Bloom, APF CJF. For more Natural Angle articles and tips, click here.
Roy Bloom, APF CJF
Roy Bloom has been shoeing horses since 1973. He has been a member of the American Farrier’s Team on two different occasions and for many years served as the manager of the team. Roy has always been willing to share the extensive knowledge he’s gained over the years with members of the farrier industry. In addition to his farrier background, he developed a strong interest in blacksmithing and tool making and for many years has been manufacturing a broad range of farrier and blacksmith tools. He also has a fully equipped shop and the ability to do a wide variety of ornamental and artistic work. Roy’s work as a clinician has earned him the Educator of the Year Award from the AFA and a position in the Horseshoer’s Hall of Fame.