Creating a center line

[klammer]

Hope this is not asked to often but I could not find much in my searching. I am curious as to how / what folks use to draw the centerline on on a blank before grinding. Do you use just 1 line or do you use 2 to dictate thickness of edge before HT? Any info would be great aqs I have been struggling to come up with a simple and effective method.
Thanks!
Klammer

 

[Jason Fry]

Simplest way: Use a drill bit the same thickness as your blade stock. Lay the bit and the blank flat, and use the point of the bit to scribe your line. Flip the blade over and do it from the other side, just in case you bobbled a bit. You'll end up with either one center line or two lines close together, either of which will be the guide you need.

 

[Ilovetoolsteel]

Hope this is not asked to often but I could not find much in my searching. I am curious as to how / what folks use to draw the centerline on on a blank before grinding. Do you use just 1 line or do you use 2 to dictate thickness of edge before HT? Any info would be great aqs I have been struggling to come up with a simple and effective method.
Thanks!
Klammer

I scribe 2 parallel lines using a veriner height gauge. They sell a simple scribing tool at some of the knifemaking websites.

 

[VaughnT]

I use a tungsten scribe I bought from one of the knife suppliers. Cost me $50 and is built like a tank. But certainly not worth the money when you consider that it is soooooo incredibly overbuilt and a drill bit on a flat surface will do the same thing.

 

[blindhogg]

I also use a height gage and a granite plate to scribe my lines. I used to scribe one line but have found it to be much more accurate to scribe two lines now about .020 or less apart.

 

[silver_pilate]

I scribe two lines usually using a height guage with carbide tip and occasionally using one of JT's guages that he sold on here a while back. Both work well on my granite plate.

--nathan

 

[Wandering Thinker]

If you have a hard time seeing your line(s) once you've chosen you preferred method, try running a felt tip pen (Sharpie) across the edge first. I saw a you tube video where a guy had Dycem (Dycum, Diecem, Diecum, no clue on the spelling) put on his knives to help with grinding as well. Its a blue dye and the video is "Making A Camp Knife - Adm Knives" on YouTube. My dad (who is teaching me) just uses something that looks like an adjustable square and sets it to 1/16 (half the thickness), and then free-hands it.

 

[Darrin Sanders]

The blue stuff is Dykem. It is machinist's layout dye. Heat has little to no effect on it so you don't lose your lines once they are marked. I mark 2 lines, the distance between the two is determined by steel type and what the blade will be used for. After the lines are marked I use an old belt to put a 45 degree bevel on each side, then I put on a fresh belt and start grinding my bevels. Putting a 45 on first helps to keep from shearing a lot of the abrasive off of the new belt. Hope this helps.

 

[LRB]

Mr. Sanders has it down correctly. The 45° angles insure that your edge is set with no worries that the lines will disappear to rust, heat, or any other reason.

 

[Bruce Culberson]

On 1/8" or thinner stock I just eyeball it as I'm grinding it. On forged stuff it's the same. When I'm doing stock removal on 5/32" or thicker then I scribe lines with my stainless steel calipers. On 3/16" (0.1875") steel I set the calipers at 0.08" scribe each side and leaves ~0.0275" for the edge.
Bruce

 

[p moore]

I simple use my dial calipers. Find your thickness, divide in half, add about 10 thou, and let one leg ride the side of the blade, and the other on the edge. Repeat this on the other side of the blade. The steel in the calipers is plenty hard to scribe blade stock. If they do dull up after years of this simply dress the ends on a 400 grit and start again. I have used the same pair for about 10 years. Best to finish the edge profile in a 220 grit running across the edge. the lines will just jump out at you.

Paul

 

[Robert Mayo]

I use this easy to make edge scribe.

Bob

 

[tedinatl]

Bob, what did you use for the tip?

 

[silver_pilate]

My guess is it's a carbide point that can be readily purchased at any industrial supply.

--nathan

 

[Robert Mayo]

My guess is it's a carbide point that can be readily purchased at any industrial supply.

--nathan

Just what he said:thumbup:

Bob

 

[jll346]

Here is one I use with good results. http://www.texasknife.com/vcom/product_info.php?cPath=884_810&products_id=1074

 

[klammer]

Came up with one tonight that worked well. Coat the eadge in red sharpie, and then use the drill bit to scribe the line. Makes a very visible line. it does wipe off but easy to redo....

Thank you all for your input!

 

[mostho]

I made this scriber thingy with a block of alluminium and using some old drill bits.
It's easy.
I can do everything in micrometric steps. Just set up the height, lying all on a glass plate, scribing is easy and effective.

By the way the use of drill bit alon of the same thickness or slightly smaller is the trick that cannot fail. I use it a lot before.

Cheers

 

[Fletch Helical]

I use my Mitutoyo vernier height gauge I picked up from a guy for 5 bucks. I actually paid $10 for that and a Starrett caliper combined so 5 bucks a piece . Measure the height on a granite plate, mark center then measure off equally depending on what I want the thickness to be, i.e. if I want it 40 thousandths then I'll got 20 and 20 off that line.