That "Filed" edge

    It's pretty common knowledge that Howard Hill used a file to sharpen his famous concave edge Hill broadheads.  He'd designed the head to have minimal surface for air to contact in flight, thereby minimizing or eliminating the tendency for the head to windplane.  He tested his heads in a wind tunnel which was granted use by his friend Glenn Curtiss of aeronautic fame.  The concave edge lent itself to increased penetration in game and Hill used this type of head and it's various prototypes throughout most of his hunting career.  He figured out a way to put a hunting sharp edge on that steel, and he passed along his technique for others to emulate and from that time 'til this,  that edge has been a bugaboo in the broadhead world.

    Back before we had all the cool gizmos to hold a broadhead perfectly on plane on a sharpening device, the arrow was held in the user's hand and the user stroked a file along the edge to set a bevel and got the bevel nice and thin and sharp.  The user then went hunting and that was that.  Broadheads were homemade and the edge was the work of lots of filing and patience, but once the edge profile was there, it was just a matter of touching up the blade to keep it sharp.  Back in those days, most kids carried a pocketknife of some sort and learning how to sharpen a blade, whether it was the knife, or the scythe, or the ax, was a skill learned at a fairly young age.  Then broadheads starting becoming mass produced with a pre-ground edge bevel profile and all someone had to do was run it along a stone or some light swipes with a file and the broadhead was hunt ready.  The relatively shallow edge grind and soft steel of a lot of heads made it an easy process.  Following progression of time, replaceable blade heads became popular for the guys who didn't grow up sharpening their pocketknives and who couldn't really get the hang of sharpening steel to a finely honed edge whether by file or stone.  And now here we are, a generation or two later and lots of newcomers to the sport of hunting with arrows...and the relearning of the art of sharpening broadheads with a simple method of a file.  The sharpening gizmos help a lot of guys with a variety of broadheads, but for the Hill style of broadhead, there has remained a certain amount of difficulty due to the steel and head design to getting the head "razor sharp" for hunting.

     First things first. Hunting arrows are traveling pretty quickly to the animal with sufficient force to push a relatively sharp instrument through the hide and into the vitals for a humane kill.  Adding to the level of sharpness by making them whisker shaving sharp is up for debate as to whether it will kill an animal quicker than just an edge made with a file which may not be shaving sharp.  We'll let that debate go for now, and focus on how to get the edge on a broadhead that Hill preferred and was followed by Schulz and a whole lot of archers past and present.  That elusive sharp filed edge.

     Hill put the jagged filed sharp edge on his heads in a unique way, and was satisfied by the jagged edge cutting through the varied mediums of an animal...initial hair, then hide, bone and soft tissue, blood vessels, veins and arteries.  He wanted an edge that stayed relatively sharp in his backquiver with minimal touchups.  So he would file the broadhead edge on a relatively steep angle from rear to front until it was "razor smooth".  Not razor sharp.  Once a good smooth edge was there, he would reverse his file and drag one of the file corners downward and forward along the blade edge with considerable force to put little serrations into the smooth edge.  Then he dressed up the edge lightly with light file strokes to align the serrations a little.  That was it.  The heads didn't feel particularly sharp to anyone that was expecting a razor sharp blade.  But they worked really in the field, helped along by the concave blade geometry and 3:1 broadhead shape.

     Followers of Hill's sharpening techniques have generally conceded that although the head's don't feel necessarily all that sharp compared to a honed razor edge, the reputation of that jagged edge is that it works well doing it's job of slicing into game and causing blood loss and hemorrhage.  But how to go about getting that edge and feeling confident to hunt with that edge and then seeing it's benefits on game is lost on a lot of people.  I love this kind of edge and have used it for all my hunting since the mid-80s and following is the techniques I use which differ slightly from Hill's, but I believe will put the jagged edge on the head quicker, and be sharper.

    

     This is a close up view of a Hill blade edge and a Zwickey Eskimo blade edge that I have filed using these techniques.  A very small jagged edge, but it is thin and sharp and will actually shave hair.  It is easily touched up as necessary.  Schulz was asked multiple times, as he supposed Hill was...."how do you keep your broadheads sharp in a backquiver?"    Schulz and Hill's reply..."with a file, how do you keep yours sharp?"  Keeping heads sharp in any kind of quiver is the duty of the hunting archer, and regular touchups should be done as necessary, whether the head is slid into foam, or rubber or loose in a quiver bottom, they can get dull due to handling or moisture corrosion.  If the edge is initially set with a file, it can be touched up with a file no problem.   No need for any other sharpening tool, unless of course, the user wants a different kind of edge.

     I set the edge bevel on a Zwickey, or other straight edge heads like Grizzly broadheads with a large flat mill bastard file, usually 8" or 10" and go to town getting a flatter edge angle than the factory edge on the edge closest to me.  Then I micro bevel the off side of the edge, creating a double bevel head of sorts.  But the majority of the blade work on the near side makes it look like a single bevel broadhead.  The micro bevel makes the edge stronger than the single bevel on softer steel. I get the edge bevel nice and uniform and smooth and pretty sharp.  Following that comes the key to the whole technique.  The round chainsaw file.  Usually in the 7/32" size but 1/4" also works well and I add a wood cap on the tang end to make it more comfortable to use, as is shown.  I proceed to put a slightly steeper angle on the larger edge bevel with the round file, really digging the file into the steel and this produces a very jagged result on the steel.  I flip over the head and on the micro bevel side I also file from rear to front with only slightly lighter strokes, then flip the head over and finish with light swipes on the larger bevel to align the jagged edge...sometimes called aligning the burr. I don't want a thin wired edge, as that is a delicate thing, but a thick ragged burr is ok and aligning it makes it feel thin and sharp.

     This edge is durable in my backquiver, and deadly on game. To me, it's always seemed that I get really good bloodletting on a variety of vital hits, so I know it's doing some serious damage to arteries and veins and whatever else it is cutting.  The jagged edge doesn't allow the rubbery smooth surface of veins and arteries to slide past without getting cut. It also goes right through bone, gristle, hog shields and whatnot and remains sharp.  

     But what about the concave edge on the Hill heads and the ferrule getting in the way?  That's the complaint I hear the most about getting them sharp.  Well...I forgo the flat file and do all the filing on my Hill heads with the round file.  It follows the contours of the concave edge nicely and puts that ragged edge on quickly and easily.  I do the same technique, large flatter bevel first on the near edge and then a micro bevel on the far edge.  With the round file, I remove only a slight amount of ferrule material in setting the edge bevel, it works just wonderfully well.

    With this technique, I can get a factory edge Zwickey jagged file edge shaving sharp in two minutes total time for both edges.  Same with the Hill.  And I only need to take a round file with me in the woods for touchups.  Carried in a little sleeve inside my quiver.  Super simple, super efficient and super deadly on game.

    Try it...comment on it.  Let me know how it works for you.  It's worked for hunting archers for a very long time, you can join them as well and keep the tradition of the filed edge going...

     And remember to Shoot Straight.