How to create a bevel on a broadhead?

[JDP12]

I'm interested in creating my own broadheads, and have read a few articles on it, especially Ashby's article on single bevels.

I know how to temper a head and braze it to a ferrule and all, but I still would like to know the best way to create a single bevel on a broadhead.  

Does anyone have any tips for me?

Should I just use a bastard file or something?

I have some ideas but I would just like some input.  

Thanks

[JDP12]

Should I grind a bevel on with a grinding stone?

Could that be an option as welL?

[Soilarch]

Never made a broadhead...but I think I understand the question.

It doesn't really matter how you remove the metal at first. (file, stone, angle grinder, bench grinder)  Just devise some way of keeping the exact same angle every time. If you can do that with a file by hand or need to come up with some sort of jig for the file/stone/grinder you're good to go.

THEN you can worry about actually sharpening them.  Soom like files some like stones.  To each their own on that one.  If you use the search feature I'm sure you'll get all kinds of threads dealing with how to sharpen broadheads...anything that mentions Grizzly's will be about single bevel.

[BobCo 1965]

You may want to consider something like this. I'm thinking of getting one myself.

 http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95236

[Sharpster]

JDP,

I'm no metalurgist but, I think grinding the primary bevels before heat treating would make the process and particularly the final sharpening far less labor intensive. (if it can be done like that).

Either way, you will save yourself a bit of sweat and aggrevation by making some type of fixture to hold the heads at a constant angle during the grinding process. This will also insure uniformity from bevel to bevel and broadhead to broadhead.

I'd like to point out that using a grinding wheel of any kind will produce a hollow-ground bevel geometry which, the good Doctor has found to be far less desirable/durable than a true flat grind. You could get a flat grind using the side of the wheel or a disc sander but, be aware that there are potential problems with this too.

On circular wheels/discs, the outer perimiter of the wheel is moving much faster than the center is. This will result in the end of the blade near the outside edge of the wheel being ground faster than the end near the center. You can overcome this problem by moving the broadhead across the wheel as you grind, you just don't want the head to climb onto, or drop off of the edge of the wheel. (instant divit)

I like belt sanders because they eliminate all the above difficulties. You'll still need a jig or fixture of some kind to hold the correct angle but using waterproof coarse grit silicon carbide or better yet zirconia belts (Mcmaster-Carr)allows you to set the bevel quickly without worry of overheating the blades because you can quench them frequently and not ruin the belts. I have found that aluminum oxide belts are pretty poor for metal stock removal.

Also whenever using power tools to sharpen any blade, be sure the tool's rotation is away from you so if the blade ever grabs, it will be thrown away from you not into your body. Hope this helps,

Ron

[Jeremy]

Ron nailed it.
You can almost completely grind the bevel before heat treating.  Just leave enough metal to be sure you don't burn the carbon out of it by overheating.

[JDP12]

ok sounds good.

Then I have a question on how exactly a single bevel works.  It may seem stupid but..

It seems like in pictures of single bevel broadheads only one side of the broadhead is sharpened, but I think that doesn't make sense.

So is a single bevel just a normal broadhead, only without a double bevel on each edge?  

I guess I would just like a little more explanation on creating a single bevel edge..

Sorry if it seems like a newbie question but I just don't quite understand it, please be patient

[Sharpster]

JDP,

No problem, that's why we're all here.

Yes, you are correct, a single bevel broadhead (or knife) has an inclined bevel gound on one side of the cutting edge and the other side is left completely flat. Go look in your kitchen knife drawer. Look at a serrated knife blade. You'll see that that only one side is beveled. The same applies to broadheads except that there are two individual blades.

Here's a side view of a Steelforce LH single bevel:
 

Another view of the same head.
 

[Sharpster]

Single bevels are ground either "left hand" or "right hand". The broadhead in the pics above is a LH.

You can tell one from the other by holding the broadhead horizontally, with the tip pointed away from you. In this position if the bevel you can see is on the left blade, it's a LH single... If the bevel you can see is on the right blade, then it's a RH single.

If you're going to make the broadheads yourself you should match the bevel to your fletching: Left wing fletch= LH bevel on the broadhead... when the arrow is fleched with right wing feathers, a RH single bevel is the optimum combination.

Be sure to post us some pics of your broadheads when they're done!

Ron

[JDP12]

so on that broadhead, the bevel on the left side is only a single bevel?

How should I determine the best angle for the bevel?

Should the single bevel go all the way down to the opposite side of the blade? So it covers the whole "depth" of the blade?

Thanks

[Sharpster]

JDP,

Q: "so on that broadhead, the bevel on the left side is only a single bevel"?

A: Yes, that is correct.    

Q: How should I determine the best angle for the bevel"?

A: After extensive testing, Dr. Ashby has determined that 25 degrees is the optimum angle for a single bevel broadhead. Lower angles weaken the cutting edge and though higher angles actually strengthen the cutting edge, they also reduce the surface area of the bevel. It's the dramatic difference in surface area between the beveled and unbeveled sides of the blade that cause the head to rotate through tissue rather than just penetrating straight through like a double bevel does. The heart of this is: shoot for 25 degrees, a bit higher will still work and be strong but, less than 25 degrees will produce a weak edge which will be prone to rapid failure (dulling).  

 Q: "Should the single bevel go all the way down to the opposite side of the blade? So it covers the whole "depth" of the blade"?

A: Yes, that is exactly what makes it a single bevel.  

Keep us posted, can't wait to see the fruits of your labor!

Ron

[JDP12]

OK cool thanks for all the help!