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Main Boards => PowWow => Topic started by: StanM on February 01, 2010, 04:14:00 PM

Title: Optimum angle of single bevel?
Post by: StanM on February 01, 2010, 04:14:00 PM
I'm sure the answer to this is in one of Dr. Ashby's reports, but I can't seem to find it.  What is the optimum angle for a single bevel (or even double bevel) broadhead?  Thanks,

Stan
Title: Re: Optimum angle of single bevel?
Post by: Orion on February 01, 2010, 04:23:00 PM
Single and double bevels are a lot different.  25 degrees is the most common single bevel angle.  22 1/2 degrees per side, which yields a 45 degree cutting edge, is fairly common on two-blade double bevel broadheads.
Title: Re: Optimum angle of single bevel?
Post by: Dr. Ed Ashby on February 01, 2010, 04:41:00 PM
What Jerry said. 25 degrees for a single-bevel. You need good steel for that to hold it's edge during penetration.

Ed
Title: Re: Optimum angle of single bevel?
Post by: razorback on February 01, 2010, 05:39:00 PM
Don't want to hijack this thread, but i have a question related to this. I saw on another thread how someone had a jig for sharpening single blades. It was real simple with a 4*2 cut to 25 degree angle and a hinge used to clamp the head. Then put on a sander. Anyone remember this or have a photo.
Title: Re: Optimum angle of single bevel?
Post by: razorback on February 01, 2010, 05:53:00 PM
Found it. the search engine is a wonderful thing, LOL.
Dr. Ashby, how fine a grit do you use on the sanding disk to get acceptable sharp.
Title: Re: Optimum angle of single bevel?
Post by: StanM on February 01, 2010, 06:08:00 PM
Thanks Jerry and Dr. Ashby!  Razorback, I got what I need hijack away   :thumbsup:
Title: Re: Optimum angle of single bevel?
Post by: Dr. Ed Ashby on February 01, 2010, 09:11:00 PM
Tony, I don't use a sanding disk. I do use a belt sander of the type used by knife makers. On it I start with a course grit and end with a 400 grit ... but then I move to the fine stones and on to a true razor strop. I've also used the paper polishing wheels with fine adrasive with good results.

In the bush I now do all the finishing with the KME knife sharpener (you want the knife model for single bevel broadheads, and I use the KME broadhead sharpener when doing double-bevel broadheads and, especially, for the replacable blades - few of which are anywhere near being 'truly sharp' right from the package).

Ed
Title: Re: Optimum angle of single bevel?
Post by: Dr. Ed Ashby on February 01, 2010, 09:12:00 PM
Tony, I don't use a sanding disk. I do use a belt sander of the type used by knife makers. On it I start with a course grit and end with a 400 grit ... but then I move to the fine stones and on to a true razor strop. I've also used the paper polishing wheels with fine adrasive with good results.

In the bush I now do all the finishing with the KME knife sharpener (you want the knife model for single bevel broadheads, and I use the KME broadhead sharpener when doing double-bevel broadheads and, especially, for the replacable blades - few of which are anywhere near being 'truly sharp' right from the package).

Ed
Title: Re: Optimum angle of single bevel?
Post by: Dr. Ed Ashby on February 01, 2010, 09:15:00 PM
Tony, I don't use a sanding disk. I do use a belt sander of the type used by knife makers. On it I start with a course grit and end with a 400 grit ... but then I move to the fine stones and on to a true razor strop. I've also used the paper polishing wheels with fine adrasive with good results.

In the bush I now do all the finishing with the KME knife sharpener (you want the knife model for single bevel broadheads, and I use the KME broadhead sharpener when doing double-bevel broadheads and, especially, for the replacable blades - few of which are anywhere near being 'truly sharp' right from the package).

Ed
Title: Re: Optimum angle of single bevel?
Post by: Dr. Ed Ashby on February 01, 2010, 09:17:00 PM
Sorry for the multiple postings. The web must be wobbling!

Ed
Title: Re: Optimum angle of single bevel?
Post by: varmint101 on February 01, 2010, 09:31:00 PM
Maybe this should be a different post, but does a single bevel hold it's edge longer?  

I've got some Steel Force 200gr LW single bevel heads and I've shot one thru cans, in the ground, and into a target butt many many many times and the dang thing is still pretty sharp.  My other heads would have been dull a long time ago.
Title: Re: Optimum angle of single bevel?
Post by: Dr. Ed Ashby on February 01, 2010, 11:24:00 PM
Lower sharpening angle = thinner edge = higher mechancial advantage to the edge = "feels sharper" ... and it would, indeed, cut more efficiently than an 'equally dulled' double bevel (simply because of the edge's higher MA) ... but it should be 'truly sharp' before you use it on game.

MOST (not all) of the single-bevel BH's on the market have much harder steel in them than MOST of the double-bevel BH's, because it takes a harder steel to hold the thinner single-bevel edge during penetration. That higher quality, harder steel also means they will retain their sharpness far better than most double bevel BH's (though there is at least one double bevel with excellent, high quality steel; the Silver Flame).

Ed
Title: Re: Optimum angle of single bevel?
Post by: varmint101 on February 02, 2010, 09:02:00 AM
Okay, thanks, that makes sense.  I was just really surprised at how sharp it still is to the touch.  Don't worry, it will be truly sharp before it goes into real duty.
Title: Re: Optimum angle of single bevel?
Post by: Bill Carlsen on February 02, 2010, 09:17:00 AM
Here's the link to the "hinge jig".

http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=060487
Title: Re: Optimum angle of single bevel?
Post by: outbackbowhunter on February 03, 2010, 06:50:00 AM
Personally I like a 30 degree single bevel, a good compromise for a strong edge thats still very sharp.