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I Forge Iron

Length of hammer drifts


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High alloy drifts designed for use with powerhammers tend to be short say 3-4" (or even shorter!)  Drifts made from less expensive materials, (Spring stock or even axle material), and designed to be held in the hand or tongs tend to be longer say up to a foot long.  The size of stock to start with will of course depend on the size needed at the finish so anything from 3/8" to 2"+  in diameter.

So are you drifting for a 2 oz ballpeen or a 32 pound sledge?  (I have a number of commercial "micro" ballpeens; unfortunately I have not sourced a 32# sledge yet I think mine top out around 20 pounds right now and it's not handled as I bought it to use as an anvil...)

There are also punch/drifts and slitter/drifts which may be longer with the other tool section included as well as drop through drifts which tend to be shorter in my experience.

(can you narrow down your question a bit?)

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Ahh.  That is why I am seeing so many lengths. Making a drift for a 2# hammer to try and straighten the factory hole to begin with.  Then make my own hammer soon.

The factory cheap-o hammer is not aligned properly.  It has about a 5 degree twist which is making it frustrating to use.

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If you don't want to get too crazy with forging out a drift, you can readily reprpose an ironworkers bull pin. The round taper and length is already there for you. The ones ive owned were a 41xx alloy. Somewhere in the ballpark of 4140. All you need to do is forge it out oval and if you chose, put a handle/struck end taper on it. Should do the trick nice and easy for a 2 lb hammer. 

Otherwise, I use h13 bar stock for my drifts.A 1.25" x7/8" oval or square taper is where you want your finished depth to end up at generally. My drifts are 14" long give or take. I don't measure the length. As long as your hand isn't burning up while drifting, you're good. As Thomas said, power hammer and press drifts are much shorter from 2"-4" commonly. 

H13 is ideal IMO

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It seems like I read about a guy who forged viking style axe heads who make a long drift then cut it into 3" long sections that were used sequentially.  The shorter drifts were easier to drive because the striking surface was closer to the anvil height.  Once the hole is punched, the short drifts didn't want to wander much and they're much lighter when you're holding the head with tongs. 

I once tried to make a continuous tool that went from a slot punch to a drift.  I quickly ran into trouble trying to find some kind of bolster plate to keep from scarring up the hammer head while I was trying to pound the drift in.  Not being able to strike the point of the tool to drive it out was a disadvantage. I've seen some videos where there's a striker available to whack the sides or ends of the head.  Working alone, it's not so easy to do that with precision. 

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  • 2 weeks later...

I have heard that an  1 1/2 in. axle Is good for a drift. forge a long taper on the end, and than flatten it a bit to make  a oval shape, cut it of about 5 inches from where the forging starts and forge the end octagonal (optional)  if you want a smaller eye than just don't drive it in all the way.

                                                                                                                 Littleblacksmith

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as you look at what other hammer makers use you style drift will have to fit the handle you are using. Weight is critical for the size of the eye. some standard handle you you can get at the hardware store will work. handles have weight rating like a blacksmith handle the will work on a 2-4 Pound hammer. I cut out a piece of steel or aluminium. that my handle will slide on. and use that as a temple for making the drift   

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On 19 April 2016 at 11:22 PM, rockstar.esq said:

I once tried to make a continuous tool that went from a slot punch to a drift.  I quickly ran into trouble trying to find some kind of bolster plate to keep from scarring up the hammer head while I was trying to pound the drift in.  Not being able to strike the point of the tool to drive it out was a disadvantage. 

For the last 30 odd years I have generally used punch-and-drift tools. The few times I have had to resort to slot and drift were on Ø150mm (Ø6") holes through 80mm (3.25") square. My general rule of thumb is that the one piece punch-and-drift works structurally and aesthetically provided you don't make a hole larger in diameter than the parent bar width. The big advantage of punch-and-drift is that the bar alters very little in length...in some cases the dynamic is such that it does not alter at all.

I have solved the sides of the hole dragging into the bolster issue in two ways over the years.

My first solution was when I was punching and drifting under the power hammer. I made up a heavy base bolster from a couple of discs of 20mm (3/4") plate and a heavy wall tube. The discs were in fact washers with Ø60mm (Ø2.5") or so holes through. I then punched a series of holes through similar-width-to-the-workpiece 12mm (1/2") flats. Two or three of these intermediate bolsters per punch diameter. They progressed from just over the punch slot size to just over full diameter. By punching them from the same width material as the workpiece, I could readily align the swellings of intermediate bolster and workpiece so that the punch did not foul the bolster when it went through. The base bolster hole was large enough that the workpiece could be turned over and the punch knocked into the void. I got slick at dragging the base bolster off the bottom pallet so that when the punch fell out I caught it in a saucepan full of water.

When I developed the punching system under the hydraulic press in the early nineties, I made a sliding bolster which slides open as the punch-and-drift  goes through, thus continually supporting the sides of the workpiece hole. The initially punching is done onto a solid bar in the slide-ways which is replaced by the front slider for the slug removal and the drifting. In this system the hydraulic press is double acting so a stripper plate holds the work down as the punch is withdrawn.

Alan

ps Ooops almost forgot! the above is just for general round hole punching.

The last hammer heads I made were slot punched under the hydraulic press with the appropriate sized punch-and-drift and then opened out with a drift I had forged from Progen which was tapered over about 300mm (12") and had a parallel handle area of 100mm (4") or so. I drifted by hand over the power hammer base bolster system.

Just noticed the Op's initial problem is to straighten an existing rotated eye. I have to say drifting is not the way I would go about that at all. Unless you are very confident about moving metal you would be far better off truing it up by cutting it away with a die grinder and carbide bit. No messing about with re heat treatment either.

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