how can i make a sen draw knife

[graveyard]

id like to have some pics and info how to make a sen draw knife , the measurments ground angils ive never made one ill need to know all the angils curves so on THANKS from a novist,,

[Frank Turley]

Wow! There is lots to know. I'm not hip with sending pictures. I can send you info the old fashioned way by post, if you wish to privately send me your address.

The sen is made by fagot welding a slab of high carbon steel to a like slab of low carbon steel. The high carbon is hit when welding; otherwise the mild steel may draw too much and spill over the cutting edge. They come in various widths from maybe 1/4" to 10". The sen is a push shave more than a draw shave. Once the weld is completed, two flat stock shanks with tangs are T-welded either side to receive wooden handles. The shanks are mild steel and are at right angles to the axis of the two sharpened edges. There is a slight convexity in width to both cutting edges. The side of the blade facing the steel is "hollowed", bent, concaved a little, and this can be done cold over the anvil edge after normalizing. The cutting edges are about 50º to 60º with a slight belly in cross-section on the outside. The sen is hardened in luke warm water, but no temper is drawn. When pushed in use, the blade is slightly skewed. Because of the little flat bend in the blade, The central portion does not make contact with the steel being cut. It is going to be 1/32" to 1/16" above the workpiece. Just the fore and aft cutting edges do the shaving. A photo of a large sen is shown in the book, "The Craft of the Japanese Sword."

Those of you familiar with Japanese woodworking will know the the non beveled side of a wood chisel is relieved; it has a slight depression in it almost the width of the blade. This makes less work when flattening the back before finishing the bevel on the opposite side. On fine hand made chisels, the depression is done with a sen. That is why some sen are so narrow at the cutting edges.

I claim no expertise on this subject. I spent 6 days with the premier saw maker of Japan when he visited the States in the 90's. He made tools other than saws, including a few sen that he had for us to look at. His name is Yataiki.

http://www.turleyforge.com Granddaddy of Blacksmith Schools

[fciron]

Frank,

Is that the Japanese toolmaker who came to the ABANA conference (in Wisconsin?) with some apprentices?

They did some very cool stuff. It is really interesting to see people doing almost the same work we're doing but with almost no common history (in terms of metalwork). I got to work with some Japanese smiths for a week at the Metal Museum. It was an eye opener, really made me think about how and why I was doing things.

Sorry, I know nothing about sens. (plural spelling?) Now I'm thread-jacking.

I may have a picture of the strap and wedge arrangement used to clamp the work while finishing with a sen. I just remembered I also have one of the japanese style forges which I got at the conference auction. Why do I have that? :unsure:

[John McPherson]

Go to Don Fogg's blademithing forum, and his personal website for articles and tutorials.

http://www.dfoggknives.com/photogallery/MakingSen/makingsen.htm

[son_of_bluegrass]

What I did was to start with a half-round file that was dull enough to no longer be a decent file. I forged a tang on the far end and normalized the whole file to grind the remains of the teeth off. Not knowing the best angle, I put a shallower angle on one side (around 30 degrees) than the other (around 50 degrees). At this point the bevels were just roughed in. I then heat treated with an oil quench and tempered to 325 degrees F in an oven. That will remove some of the brittleness while leaving it really hard. Then I finished the grinding. I put a file handle on each end. After playing with it a bit I tried different angles to see what worked well for me.
If you are just looking for a start to try a sen, this works.

ron

[Frank Turley]

Yes, Yataiki was at the Wisconsin conference, but I wasn't. He was the oldest of the Japanese smiths. He has also demonstrated at The Crucible in Berkeley, CA. He is truly a sensei.

http://www.turleyforge.com Granddaddy of Blacksmith Schools