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Sean McWilliams

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Posts posted by Sean McWilliams

  1. These are all S35VN cut from the same bar, and were differentially tempered. There were three blades sent to the lab, where they prepped and mounted them for photography. I next made three blades for the edge holding and toughness tests. All blades were heat treated in identical ways and bent each to the breaking point. BTW great comment about the New Improved Plow steel.

  2. Jerrod, Thanks for jumping into the fray. You're right, the ferrite is being displaced as the carbide crystals are being packed more tightly together. This happens just above a black heat, maybe 1000F, (for the alloys I forge) but above the dreaded "blue-black brittle" range. Since this is a high alloy stainless, work hardening would crack the steel in a few blows. Work hardening does go away with higher heat, but the packing remains and is still there after hardening and tempering. Packing happens on the level of carbide crystals, in this case, chromium carbides. So, we need to be talking carbides, not atoms. The atoms are tiny, tiny and locked into the molecular structure, then, many, many molecules together form the crystals.

    Alan, if I can post a .jpg file as large as 860 KB I'll be glad to post all the photos full size, when viewed on a large screen  (mine is a 21") the edge packing is truly visible. Otherwise, for those interested, I can email the hi-res photos to your email.

    Zeb and Doug,  Skepticism about  Packing has been around longer than all of us put together. First I read of Packing was in a 1895 book by John Deere Co. describing the sharpening of plow shares, and how much "wing bearing" to put on a walking plow so it doesn't fall over in the furrow. So in those horse drawn days, "..the Blacksmith who didn't pack the plowshare was a thief and a charlitan..." who cost his customer 20 more acres of plowed field.

  3. Thanks, Mike

    This winter I taught a week long bladesmithing course at a private high school, Colo. Rocky Mtn. School, where they have a complete forging shop. 10 students, 9 of them never-evers, completed 5 layer damascus knives. The knives were as different as the personalities. It was a little scary in the current atmosphere around knives and schools in general, but well received. At the end we did a presentation and one student commented "If they only have to confiscate two or three knives, we'll probably do it again.

  4. Hi Joshua,

    Thanks for the comment. I remember those days. I went to Catholic grade school 50's, we had pocket knives, played  'strech' on the lawn. I got in trouble once over my pocket knife, well not the knife exactly. I didn't want to wait in line at the pencil sharpener, so I pulled out my pocket  knife and whittled a point on my pencil, letting the shavings fall under my desk. Sister Helen Brimstone was furious, made me sweep it all up and stand in the cloak room for the rest of the afternoon. It was winter, and there was no heat in there, so I borrowed some coats. Back then, the nuns confiscated a lot of yo-yo's, but not knives.

  5. Steven,

    The answer would be None of the Above. I didn't know I was sending it as a personal message, I reposted as a comment, subsequently. I was using the corn flake analogy as an analogy to describe what packing does. There is no empty space. I am actually hammering the bevels near the edge of the knife and on the anvil. I'm not shaking the knife or tapping the bevels.

    • Temperatures above and below critical cannot exist simultaneously.
    • Normalization and forging are separate processes. Forging is forging, normalization is heating the steel to critical and letting it cool in still air.
    • Forging below critical does indeed refine the grain, heating much above critical does indeed cause grain growth.
    • My intent on posting this information is to inform and educate in pursuit of better blades.  So I can recommend some additional reading: TOOL STEELS for ENGINEERS; Pendelton, Luersson, and Palmer. The Mystery Within Steel; Leon Borgman Univ. of Wyoming. THE ART OF BLACKSMITHING; Alex Bealer.
  6. Forged means shaping, tapering, drawing and thinning the edge. Packing occurs at the last heat level before austenite formation, above the point where "work hardening" occurs. This temperature is different for different alloys. I pack my edge with a lighter hammer (1 1/2 lb.)  use 2 1/2 lb- to 5 lb. for forging. Light, quick blows along the edge turning side to side evenly. Gotta move right along before the blade is too cool. At that heat, carbide structures have formed, but not cemented, so I'm just jiggling the carbides into a tighter configuration. This is a final step, as further forging upsets the packing. It does make a difference- I can tell.

  7. You don't have to be older than dirt, but at least have some years on 'ya to remember when folding knives were just called "Pocket Knives." In the new age of retronyms the term is "slip-joint." I have fond memories of those knives, especially the ones I couldn't afford when my only income was from shoveling snow, mowing lawns, and my paper route. Thirty some years ago, I found some prime Sambar stag scales , just before the stag ban, and some red jigged bone scales like the old Case "Muskrat" that my father gave me when I was about 9. I lost that fishing when I fell in the swollen spring stream and my waders filled and started to drag me under. That knife saved my life, I hung on to my rod and reel, but lost the knife. My father never found out though, he passed away that summer. My passion for those old Pocket Knives never dragged under, just put off till now. I dug out those Sambar and bone scales, and patterns of slip-joint folders I made about thirty years ago, and the passion roared into flames! Here are a small 2-blade and large Muskrat in Sambar stag. I have enough stag to make only five more small and 1 or 2 more large single blade folders. I wish I could give one to my father, but I'll just have keep at least one for myself. Shall it be stag or red jigged bone, maybe one of each. See and hear that large Muskrat  walk and talk on my Twitter page @Bladesmith111



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  8. Have you ever had doubts about the value edge packing. Just an old blacksmith's tale? What is it, does it work, how does it work? I set about researching this subject in 1988, publishing the results in Knives Illustrated Magazine in the 1989/Winter issue. The article, titled "Microphotographing Steel" featured 400X photographs of cross sections of forged blade steels. The photos reveal considerable grain refinement due to forging, but the proof of "edge packing" was inconclusive. And there remained questions. Particle Metallurgy (CPM) steels were new on the market, and the question raised was "Does forging refine the grain in finer grain CPM steels?"

    I conducted a similar study recently and published the results, the microphotographs, edge holding tests, and toughness tests. With higher magnification, 500X, and higher resolution photography, the answer is undeniably YES! Even in fine grained Particle alloys. I didn't really see it in the packed edge until I enlarged the photograph full screen on a 21" screen. Wow! something definitely different happened at the edge. Carbide particles were not just randomly finer and finer, but arranged like tightly stacked stones of a defensive wall. To further prove what this does for a forged blade, I did edge holding tests on stock removal, just forged, and forged and packed samples. Forging improved edge holding by a factor of 2.63, over stock removal, and edge packing improved edge holding 1.37 X over the forged blade. Bending tests proved significant improvements in toughness. I published the full story on my web site https://seanmcwilliamsforge.com/scientific-knife-testing-proves-performance-and-durability-of-sean-mcwilliams-knives/ Photos attached here are not full size, so if you want to see them on a big screen, I can email them info@seanmcwilliamsforge.com



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