What Grind is best?

[xspook2158]

How do I know or find out what type of grind is best for a certian type of knife (Examples Hollow vs Angle or Flat Grind)?

Tac, utillity, sportsman, hunter, etc

Is it a matter of personal opinion or functionality?

Jeff

[Eli Jensen]

Hollow grinds are good for slicing but are the weakest grind.

Convex grinds are good for chopping and are the strongest, but too bulky to slice well.

Flat grinds are a compromise between the two.

[Doug Lester]

Those are the basic grinds but there are others like the scandi grind where there is one bevel from the sharp edge back at least most of the width of the blade. It would be a real slicer, not a chopper.

You can have a saber grind where the bevel is only ground about 1/3-1/2 of the width of the blade. It results in a less acute angle to the edge and has more steel behind it for strength. It also allows the back of the blade to be thicker and stronger. Sometimes seen in knives like large bowies or tactical blades where more strength is wanted.

There is also a hollow grind that was used on swords to make them lighter. The grind was not take down to a fine edge or nearly a fine edge. It was left just a little thick and the secondary bevel was cut into the edge. It removed weight from the blade but left enough steel behind the edge for strength. This form of a hollow grind can be seen in some knives but it's usually seen as a sign of a poor design as in to lighten blades made overly thick to counteract the brittleness of the steel used.

There are some other variations on the basic grinds but those are what I could come up with now.

Doug

[xspook2158]

I guess what confusses me is, that I see so many so called TAC or MIL knives that are Hollow ground and boasting about their strength for prying and ability to hold an edge. These knives do not just have a blood grove ( Yeah I know its called a fuller ) they are completly hollow ground. I also understand that the RC hardness comes into play at some point.

Guys, I know I may be thinking out loud.

I also ask a lot of questions, Thank you for ther replies and for your patience.

Jeff

[Ray Rogers]

I think you already know what grind is most appropriate (notice I didn't say 'best') for a particular application from what you said about TAC or MIL knives. You can fudge the design and make something, say, a hollow grind, able to perform where it normally might fail. For instance, a hollow grind which can also be used as a pry bar - you just make it from very thick steel and leave part of the blade at full thickness. Does this knife do anything particularly well? Probably not. Each grind has its strengths and weaknesses and those are varied further by the heat treatment. Ultimately, the choice of grind comes down to what you want the knife to do best. When you look at it that way, it becomes pretty clear why each grind exists and I think you see that already and just want someone to verify what you're thinking. OK, I think you're right ....

[Eli Jensen]

Thanks Doug for finishing up the basics for me. Was going to but the wife was getting naggy to use the computer.

Do those hollow ground knives, does the grind go all the way up to the spine? If i does not then there is a portion that is very thick near the top. This is what imparts the strength for prying. As opposed to a full flat grind, which would bend much easier. Not sure though compared to a non-full flat grind.

In my opinion, a lot of it is marketing as well.

[Doug Lester]

Yes, you will see knives that have a hollow grind that doesn't go all the way to the edge. This allows a more acute secondary bevel to the edge which will slice better than a less acute edge. The thickness at the tip is avoided by taking the grind around the curve of the tip of the blade. Much the same has to be done with other grinds that do not go all the way to the spine. It is even better to follow the curve of the blade when applying the secondary bevel to a blade to avoid widening of the edge at the tip.

You are correct, it's a lot of marketing. This whole tactical knive thing is a lot of marketing hype with the "tanto" blade and saw backs that are next to useless. I've handled a "saw back" blade where the teeth had not offset and were actually thinner that the thickest part of the blade. I saw a picture of one of those saw back German Pioneer's bayonettes from WWI. They had real saw teeth; they were offset which made the cut wider than the thickness of the blade. These things you see now day are mostly jokes made for consumers who want to prove their manhood with the "weapons" they possess.

It is also worth noting that in WWI German soldiers caught with saw back bayonettes were often sumarily exicuted as war criminals.

Doug

[Eli Jensen]

"It is also worth noting that in WWI German soldiers caught with saw back bayonettes were often sumarily exicuted as war criminals.
"

Ever read All Quiet on the Western Front? Great illustration of that point. Similar to English longbowmen captured by the French.

Saw teeth that are THINNER than a blade? That certainly is going to be a frustrating task.

[Doug Lester]

I owned the blade, The spine was slightly beveled and the teeth, with no offset what so ever, were cut into it so that the blade flaired from the tip of the teeth to about half way down the blade where it was the thickest. Some on was obviously going for visual effect and not use. It was a so called survival knife. It was too heavy, too thick, poorly made (the handle eventually came off the blade), but I did have a nice hollow handle for storing matches. I don't know where it eventually got to after I reglued the handle but I don't miss it.

Wars are not good for fostering humanity as much as forstering inhumanity.

Doug

[xspook2158]

Thanks for taking the time to reply.

In a round about way I knew the answer.

Its like some of the tyers, I know advertise a certian Fly as the Ultimate Fly.

What they dont tell you it may be the ultimate fly in some states, sometimes depending upon the general area, depending on the weather and also depending on what hatch is out and what stage the hatch is in at the exact time. Whew!!!

As always, I thank all of you for the help and information.

Jeff

[GreenhornMining]

Of course different blades are usefull in different situations, but swedish mora knives have won me over to flat ground blades. In fact I am considering buying some mora knives ($8 each) cutting the handles off, and making some custom hidden tang bush knives.