My Community College Knife Making Experience

[bestgear]

Thanks for taking a peek at my adventure into knife making which I’ve had a mild interest throughout my life. My intrigue is the marriage of form and function and seeing that develop with your own hands and tools. When my local community college offered an 8 week, 32 hour class for $125 I couldn’t say no; my 1st class is Monday 6/2/25.

My hope here is to document each 4-hour class and provide the reader a glimpse into the process, the trials and the tribulations. I’ll do my best to provide some photo journalism along the way because sometimes they mean more than words.

Today I’m ordering my supplies from a list provided by my instructor. The class materials and equipment list is:

• EQUIPMENT
  Safety Glasses
  Apron
  Head Lamp
  Measuring Tape
  Scribe
  Files

• MATERIALS
  (1) 5/32" 440C bar steel 1-1/4” wide, 3-ft long
  (3) 1/8" pin stock 416-stainless, 1-ft long
  (1) 12" x 12" Black Canvas Micarta
  (2 each) 2X72 grinding belts 60, 120, 240, 400 grits
  (2 each) sheet sandpaper 60, 120, 240, 400 grits

It was recommended to order all supplies from POP’s Knife Supply https://popsknife.supplies/ who I’ve never ordered from before. The instructor of the class is Ed VanHoy who is a designer at Columbia River Knife & Tool (CRKT). Ed invented the lauded Snap Lock™ mechanism, which earned him a load of accolades, including: the A.G. Russell Most Innovative Folding Knife, Most High Tech Design-S.I.C.A.C, Best Fantasy Knife in the Ohio Valley Knife Show 2005, and Knife of the Year at the Blade Show 2004. Ed is living proof that if you love what you do, the rest comes easy. That’s been my credo my entire life.

Come along for the ride, this should be interesting!

[Steve Warden]

Sounds cool!
I'll be checking in to follow along.

[dlr110]

This sounds really good Tom. I'll be looking forward to hearing/seeing your progress, good luck...

[1967redrider]

Very cool, Tom! In addition to the $125 tuition, how much do you think the supplies will cost? That's a cool website. There used to be a knife making co-op in Arlington, which is close by. Not sure if it survived the Covid era.

[bestgear]

Very cool, Tom! In addition to the $125 tuition, how much do you think the supplies will cost?

The materials were just shy of $150.00 John and that included a $30 UPS shipping charge.

[bestgear]

Day 1

I arrived at my class about 10-minutes before the start and was greeted by 8 men and 1 woman and the instructor Ed VanHoy. Brunswick Community College recognized the expanding community of studio-based creative artisans and the role of the arts, entertainment and tourism in the economic development of North Carolina. As such, they built a new building specifically dedicated to knife making, ornamental blacksmithing, and metal sculpture complete with brand new chop saws, grinders, band saws, welders, etc. My class is the first class to use the new facility and equipment.

The vibe from the beginning was relaxed, informal and supportive. A few of my classmates had prior experience with forging, grinding and finishing but most of us were scratching an itch for the first time and simply seeking another life experience. After the business of confirming the class roster and brief introductions, we jumped right into designing the knife that each of us was planning to produce by the end of the class. The instructor explained that a balanced knife should feel comfortable and easy to handle, with the weight distribution being a key factor in ergonomics. He further explained that the size and proportions of the blade and handle should be appropriate for the tasks the knife is intended for.

STEP 1 – Design
The first lesson that Ed taught us was the “Golden Rule (2/5 and 3/5)” which establishes the blade-to-handle length. In essence, the total length of the knife can be related to the blade length using the golden rule, with the handle contributing the remaining proportion. I designed my knife to have the blade length be 1.6 times the handle length. The golden rule will also be applied to other aspects of my knife, such as the thickness of the blade, the vertical and horizontal control lines and the spacing between handle pins, to create visually appealing and balanced proportions. While the golden rule can be a helpful guide, we learned that ultimately, the handle-to-blade ratio is determined by the intended use of the knife and the desired balance of the knife.

Next, we learned that the golden rule could contribute to a knife's aesthetic appeal, but ultimately, the proportions should also be pleasing to the eye. The instructor explained to us how knife makers often develop their own unique styles and preferences, and the golden rule becomes just one of many tools they can use to achieve their desired aesthetic. The instructor made the job of designing our knives easier by having a dozen or so Lucite templates of patterns which are some of the 17,000 knives that he has handcrafted over the past 50 years. We could use these template as-is to design or knives, combine the handle of one template with the blade of another to create a new pattern or design a knife pattern that wasn’t represented in the templates. I drew 6 knives and ultimately settled a sheepsfoot pattern to be used as a small kitchen chopper that was hand drawn and not taken from one of the proven templates.

Everyone settled in on their designs quickly and once approved by the instructor, the drawn templates were cut out with scissors and the overall length of our knives were known. We then proceeded to the chop saw to cut the section of bar steel that was needed for our knives. The instructor was intentionally hands-off so that each of us could not only experience the interaction of the material with the tool, but we could claim 100% of the handcrafting of our knives without assistance. Safety was paramount to every tool that we used, and briefings were held before the use of any tool and oversight provided during the use of any tool.

STEP 2 -Cut bar steel to length
We then took the cut bar steel to the grinder and using a 60-grit 2”x72” belt we de-burred both ends and debarked both sides of the bar steel. Here we learned the fine art of plunging the material into the tool and how to safely hold the material without harming your hands. When the instructor was satisfied that we had successfully accomplished both tasks, we then applied Dyken layout fluid to 1-side of the bar steel and within 30 seconds it was dried and ready to be scribed. Our templates were then placed on top of the blued steel and carefully traced using a sharp metal scribe leaving marks that stand out when the template is removed.

To conclude our day 1 class, the instructor provided us with a vision of the way forward to complete our knives. He started by saying that we weren’t blade smithing (forging) our knives but instead we would be grinding them to remove material and finishing them with either handles or covers. I came to learn that covers are the term used to describe the material that encompasses a full-tang knife (or a pocket knife) and that handles are the term used to describe material that encompasses a partial tang knife (where the tang skips into the material). The instructor said that in teaching over 200 knife making classes in the past 32 years that every knife that was started was ultimately finished and that we should anticipate the same outcomes with this class. We ended on a high note, cleaned up the shop and I left the campus with a strong sense of accomplishment and satisfaction.

[Steve Warden]

Too cool!
Thanks for taking us along!!

[1967redrider]

Awesome, Tom! Looks like a cool experience and you have all the tools necessary for success, including a great instructor.

[ScoutKnives]

Very cool !

[doglegg]

Too cool!
Thanks for taking us along!!

Agree.

[bestgear]

Day 2

STEP 3 – Profile knife by removing stock
We started the day with the goal of removing all the stock from our pieces of steel to match our drawn templates. For some of the students this could be accomplished on the two Jet grinders by removing the large wheel that was used last week for deburring and installing 2 smaller wheels and a platen. For the remainder of the students, a combination of the grinders and the band saw were needed to meet today's goal.

Since we made use of the grinders last week, they were already set up and ready to be reconfigured for today’s tasks. Re-configuring the grinders to accommodate 2 smaller wheels and a platen was quick and easy and within a few minutes the two grinders were ready for use. My knife profile necessitated the use of the grinder for the blade profile and the pommel, and the use of the band saw on the tang.

The two Jet band saws had not been used before and had to be set up for the first time. The instructor wanted to slow the speed of the 14/10 blade to around 100 rpm but struggled with the pulley system to achieve that speed. Several students stepped in and with the help of some trial and error coupled with reading the owner’s manual, the band saws were ready to be used. Since the grinders were already occupied, I jumped in on a band saw to remove the stock on the tang of my knife.

The instructor worked one-on-one with me to teach me about how slowing down the saw speed can help prevent the blade from catching and drifting off the line. He told me to avoid twisting and not to twist my steel while cutting as this can cause the blade to bind or break. The instructor told me not to make relief cuts for tight curves but instead to use the back edge of the blade to pivot through wide curves. I was taught to focus on the path of the steel entering the blade rather than the blade itself and that it’s ok to correct cuts that drift off the line by turning the saw off, backing the material out, and restarting the cut. I had to remember that the band saw wasn’t producing the finished profile but instead was used to remove bulk stock to make more efficient use of the grinder for areas of my knife like the choil.

During the time that the band saws were being prepared for their maiden voyage, the only machines that were available were the two grinders. The students were very cordial to each other and rotated out after about 5 minutes so another student could step-in. This process generated some impatience, and a few students made use of a handheld grinding wheel. The instructor was knee-deep in band saw pulleys and belts and didn’t immediately hear the grinding wheels. When he did, he ceased that activity and used it as a learning experience for the entire class rather than reprimand the enthusiastic students. The instructor told us that grinding wheels are dangerous primarily due to the high speeds at which they operate and their ability to cut through hard materials. This can lead to severe injuries if proper safety precautions aren't taken, including the potential for wheel breakage and projectiles flying at high speeds. The instructor told us how grinding wheels are prone to breakage, especially if they are not properly mounted, stored, or used. When a wheel breaks, fragments can fly off at high speeds, causing severe injuries to the operator or those nearby. It was the best takeaway of the day!

When all the students had finished the goal of removing all the stock from their pieces of steel to match their drawn templates, the instructor pulled us together to give us some insight into what we’d be working on next week. The instructor complemented us for having the profiles of our finished knives done after week 2 of 8 but reminded us that much more stock was going to be removed before our steel bars became a knife. Our instructor went on to say that the removal of stock would be done using “control lines" or "plunge lines". These refer to the lines where our blade's bevel meets the ricasso (the blunt part of the blade near the handle). He said that they can be straight, curved, or have varying textures and that these lines play a role in the knife's aesthetics and function, potentially providing a grip or a transition point.

Once again, we ended up on a high note, cleaned up the shop and I left the campus with a strong sense of accomplishment and satisfaction knowing that piece of steel bar matched the paper template of a knife that I drew a week ago.

[1967redrider]

Nice progress, Tom.

[Steve Warden]

[Jeepergeo]

Following.
Sounds like a fun class.

[doglegg]

Thanks for sharing and for making it so interesting.

[bestgear]

DAY 3

Today was a fun day for me because the instruction was highly technical with enough variance to allow my inner artistry to be satisfied. Today we would learn how to remove steel stock using “control lines" or "plunge lines". These refer to the lines where our blade's bevel meets the ricasso (the blunt part of the blade near the handle and they play a role in the knife's aesthetics and function and in some cases providing a grip or a transition point from the handle. Today we would also get to use the drill press for the first time.

STEP 4 – Scribe layout lines
To get started we had to scribe layout lines that we would use when grinding the shape of our knives. These lines consist of a primary bevel line, horizonal control lines and vertical control lines. I have put forth my best effort to document each of these layout lines, but my notes were taken in a fast a furious manner and I did my best to capture the exact technical specifications and details.

STEP 4A – Primary Bevel – The 2 primary bevel control lines are used during the initial grind to establish an approximate 30° bevel. To create these layout lines, the width of the steel was measured at the blade edge with digital calipers, 0.030” was subtracted from the blade width and that result was divided by 2 to yield the amount of steel that would be taken off each side of the steel. For my knife, the calculation looked like this: (( 0.170 - 0.030 ) / 2 ) = 0.070” from the blade edge. The image below shows the 2 primary bevel control lines with a 0.030” gap between them.

STEP4B – Horizontal Control Lines – Two (2) horizontal control lines are used in both the initial grind and subsequent grinds to build on the primary bevel. These layout lines need to be scribed now before starting the primary bevel grind so that enough steel is present to accurately mark the 60-grit grind line and the top horizonal grind line. The 60-grit grind line was scribed at 0.375” and the top horizonal grind line was scribed at 0.500” as depicted in the image below. These measurements were provided by our instructor.

STEP4C – Vertical Control Lines – The vertical control line is used in all the blade grinds and establishes a clean and crisp transition between the ground bevel and the unground portion of the blade. For my knife, I measure 0.250” (¼”) from the tip of my choil towards the tip of the blade and scribed that line 90° from the blade edge to the top horizontal grind line that was already laid out. This measurement was provided by our instructor.

STEP4D – Handle Pin Holes = The instructor asked that each of us use at least six pins to attach our covers to the knife. To lay out the handle pin holes, the rule of thumb that our instructor follows is to locate pins no more than 3-times and no less than 2-times the thickness of the pin. In our case we are using 1/8" (0.125”) pin stock of 416-stainless which would make the rule-of-thumb layout lines no more than 0.375” (( 0.125” x 3 ) = 0.375” ) and no less than 0.250” (( 0.125” x 2 ) = 0.250” ). For my knife I measured 2.5 times the thickness of the pins for my handle pin holes, set the digital calipers to 0.3125” and scribed a line on 1 side from the edge of the steel. I then measured the distance from the choil to the end of the handle (4.00”) and evenly divided that by 3 and scribed 3 tick-marks on the blade edge handle hole pin line. I then used a straight edge to mark the corresponding 3 tick-marks on the spine edge handle hole pin line. The image below depicts the layout of both the vertical control line and the handle pinholes.

STEP 5 – Grind to the 30° primary bevel
I learned quickly that beveling is by far the hardest part of crafting a blade so far. Creating a perfect bevel is a skill that requires many hours of practice to master and watching our instructor show us how it’s done proved that point. Bevel grinding entails applying pressure to your knife at an angle to create an angled blade edge. Ensuring the grind lines are crisp and clean when beveling would be impossible without layout lines. We were taught that one of the many tricks to beveling is to ensure you’re grinding smoothly from one side of the blade to the other. If you hesitate or try to correct a grind as you’re moving from side to side, you’ll likely dig into the material and create a wobble in the grind line. It’s better to commit and keep your movement steady as you grind from one side to the other. Smooth movements equate to a smooth blade.

STEP 6 – Grind to the 60-grit horizontal control line
The next thing I learned when beveling is ensure you’re grinding from the edge towards the spine of the blade and not the other way around. It’s best to slowly move the workpiece towards the belt and allow the edge of the metal to lightly kiss the belt before applying your angle and pressure. If you press too hard initially, you could cut the cutting edge too far. Again, I was reminded that slow and steady is the key.

The plunge line for my bevel could either be crisp and sharp or softer and more rounded in appearance by modified by adjusting the belt tracking. I found that if the belt edge matches up with the edge of the platen then it leaves a crisp plunge line but if I adjusted the tracking so the belt hangs off the edge of the platen that it creates a smoother transition between where the belt is cutting hard and where it’s not cutting at all, which I used to attempt a soft rounded plunge line.

STEP 7 – Drill and countersink the handle pin holes
To keep the steel from wandering when the drill bit touches the steel, each of the 6 handle pin holes was center punched to create a small, conical depression that served as a guide for the 1/8” drill bit and ensured greater accuracy in the placement of the holes. Our instructor said that the key to success with the drill press is to lower the drill bit gently into the steel and apply consistent pressure. We were taught to avoid excessive pressure and not force the drill but instead let the bit do the cutting and that excessive pressure can cause the bit to overheat, dull, or break and even change the temper of our steel. When drilling my 6 holes I periodically lifted the drill bit out of the hole to clear out chips to prevent clogging. I reduced pressure as the drill bit approached the end of the steel to avoid sudden breakthroughs and potential damage to my knife.

Since the countersinks are simply an aid to installing the pins and are concealed by the covers, they didn’t need to be at a precise depth. I mounted a ¼” (0.250”) drill bit and while loosely holding the steel I slowly lowered the drill press just enough for the drill bit to center on the 1/8” hole and I countersunk all 12 holes (both sides of the knife). The image below shows one side of the knife with 6 holes countersunk.

STEP 8 – Saw jimping lines on the spine
Jimping is small notches that are cut into the spine of the blade in the area between the sharpened edge and the handle. Its primary purpose is to enhance grip, especially in wet or slippery conditions, and provide a more secure hold by increasing friction between my fingers and the knife. This wasn’t something that everyone in the class was doing but I felt that it would allow for better finger placement and leverage for delicate tasks like carving or detailed cutting with my knife. I also felt that my sheep foot style blade could be used with greater precision thereby leading to cleaner cuts and finer results. Beyond functionality, I also felt that jimping on my knife would add a touch of visual appeal and that the geometric pattern created by the grooves would complement the overall design of my knife, making it a pleasing combination of form and function. The image below shows my knife at the end of day 3.

To conclude our day 3 class, the instructor provided us with a vision of the way forward to complete our knives. Next week we will be completing our 60-grit grinds to the top horizontal grind line and transitioning to 120-grit to complete the pre-heat-treating grinds. We will then be heat treating our blades in preparation for final finishing. We once again ended the class in fine fashion, cleaned up the shop and I left the campus with a piece of steel that was starting to look like a knife.

[doglegg]

Tom, you are good at sharing your experience. You undoubtedly understand your instructor to be able to share with us. Thank you.

[bestgear]

Tom, you are good at sharing your experience. You undoubtedly understand your instructor to be able to share with us. Thank you.

my pleasure Floyd, I worked my whole life exercising the muscle between my ears, it feels good to create something with my hands and tools.

[bestgear]

Day 4

I arrived at my class about 10 minutes before the start ready to complete our 60-grit grinds to the top horizontal grind line and transitioning to 120-grit to complete the pre-heat-treating grinds. I was a bit concerned about the weather being over 90° F today at 8:30AM and heat treating our blades in preparation for final finishing at about 2,000° F but as soon as our instructor arrived, we were told that we wouldn’t be heat-treating today because of the extreme weather. I think this was a good call given the average age of the class is at least 60 years of age, possibly more. The instructor looked at my top horizontal grind line and felt that my blade was ground enough for heat treating which he would be doing on our behalf this coming week at his home studio so I didn’t get to spend any time at the grinder today.

STEP 9 – Finish jimping lines on the spine with a file
I used a file to finish the rough-cut saw jimping that I started last week. Filing my jimping involved using a triangular file which for those that don’t know is a hand tool with abrasive teeth, to shape, smooth, and remove material from steel. I believe it’s a fundamental metalworking skill that could be used for a whole bunch of tasks like creating straight edges, shaping curves, and refining surfaces like my jimping. The instructor taught me the fundamentals of filing which include:

• Choosing the Right File: Files come in various shapes (flat, half-round, round, triangular, square, etc.) and sizes, each suited for specific tasks. Flat files are good for general shaping and smoothing, while half-round files are useful for concave surfaces.

• Securing the Workpiece: The workpiece should be securely held in a vise or with a clamp to prevent movement during filing with the work area outbound of the vice.

• Proper Filing Motion: The files that I was using only cut effectively on the forward stroke, so I was taught to apply pressure while moving the file forward and lift it off the workpiece on the return stroke to avoid dulling the file.

• Using Two Hands: I watched my instructor use both hands to control the file, applying even pressure to ensure a consistent cut and a smooth surface, I simply copied what he was doing masterfully.

I came to learn that long, slow strokes help create a smoother surface and prevent the file from overheating. I also found that too much pressure could damage the file and lead to uneven filing and consistent movement prevents the file from digging into one spot on the steel and creating a ditch. Just like on the grinder, I used my body weight to push the file, rather than relying solely on my arms to maintain consistent pressure.

STEP 10 – Create a heat-treating pouch
Creating a single-use heat-treating pouch (also known as a tool wrap or heat treat foil) is a common technique for protecting metal parts, especially tool steel and blades, from oxidation and decarburization during heat treatment. Our instructor taught us that this helps to minimize scaling and maintain the integrity of the material's surface properties. To get started we used a specialized foil that the instructor provided that is made of 0.002” thick Alloy #321 which is a titanium-stabilized austenitic stainless steel known for its excellent corrosion resistance and high-temperature strength that can withstand the high temperatures required for heat treating our 440C bar steel which calls for 1950° F for 45-minutes.

Step10A - The lengthwise fold - The flat specialized foil was cut to a length 4” longer than our knives and folded in half creating a joined end. The foil was then folded 90° at the joined end and when uniformed across the length of the foil, folded flat the remaining 90°. The foil was again folded 90° at the folded joined end and when uniformed across the length of the foil, folded flat the remaining 90° creating a double fold the length of the foil. This double seam was tightly sealed with the light tap of an ordinary carpenter’s hammer.

Step10B - The first width-wise fold - The foil was then folded 90° at one of the open ends and when uniformed across the width of the foil, folded flat the remaining 90°. The foil was again folded 90° at same open end and when uniformed across the width of the foil, folded flat the remaining 90° creating a double fold the width of the foil. This double seam was tightly sealed with the light tap of an ordinary carpenter’s hammer and a pouch is formed to accept the knife steel.

Step10C – The second width-wise fold - The knife steel is then inserted into the pouch so that the end of the knife steel is touching the double seam on the width of the pouch. Starting from the closed end of the pouch and working towards the open end, air is evacuated by lightly forming the foil around the profile of the blade. Once evacuated, the foil was then folded 90° at the only open end and when uniformed across the width of the foil, folded flat the remaining 90°. The foil was again folded 90° at same end and when uniformed across the width of the foil, folded flat the remaining 90° creating a double fold the width of the foil. This final double seam was tightly sealed with the light tap of an ordinary carpenter’s hammer and the heat-treating pouch is finished.

Our instructor told us to handle the specialized foil carefully as the edges are very sharp. I would suggest wearing gloves if they are available when handling this specialized foil; it’s razor blade sharp. The goal is to create a sealed pouch to minimize oxygen exposure during heat treatment and make the pouch snug but not so tight that it's difficult to remove the part, especially for oil quenching. I guess we’ll see next week how well we did towards meeting that goal.

STEP 11 – Prepare covers
STEP11A – Generate 2 book-matched covers - I chose black canvas micarta for my knife covers which simplified the process of generating 2 book-matched covers. Book-matching is a technique used in where two adjacent surfaces are arranged to create a mirror image, resembling an open book. This is achieved by cutting a single piece of material into two slabs, then flipping one slab to create a symmetrical pattern. With natural materials like wood, this is important because the finished knife will show the same grain lines at the same place along the knife tang on both covers when finished. With synthetic material like Micarta, this is not as important because the material has no grain to match.

To generate my 2 covers I drew a horizontal line 1-1/4” wide along a 12" side of the black canvas Micarta and drew a vertical line at the 6” mark creating 2 covers that are 1-1/4” wide., and 6” long. The covers were cut on the band saw.

STEP 11B – Layout master side cover - One of the covers was hand aligned to the knife steel so it extended ½” beyond the ricasso and completely covering the cover side of the knife steel. Once hand aligned, the two pieces were clamped together using Vice Grips with multiple reminders from the instructor that ONCE IN THE VICE GRIPS DO NOT TAKE THEM APART UNTIL TOLD TO DO SO. Our instructor said that this is critical to ensure proper book-matching of the covers which is a hallmark of any custom-made knife. Once clamped, the outside of the cover is scribed with an “X” to identify it as the “Master” cover.

STEP11C – Drill pin holes in clamped master side cover - Using an 1/8” drill bit, I lowered the drill press through the countersunk hole in the knife steel and through the canvas Micarta. Once all 6 holes were drilled, I ran the clamped cover and knife steel combination up and down a stationary drill bit to clear the hole to a full 1/8”.

STEP11D – Scribe master side cover to the blade profile - The blade profile is scribed in the cover material to create a rough-cut line. We were now told to remove the Vice Grips that were clamping the master side cover to the knife steel. More than one student asked a second time to be sure THAT WE WERE BEING TOLD TO TAKE THE VICE GRIPS APART.

STEP11E - Drill pin holes in the clamped matched side cover - The master side cover and the matched side cover were then clamped together using Vice Grips and the pin holes in the master side cover are used as a template to drill the matching side cover pin holes. The ends of both covers are now marked with an “X” using a Sharpie to maintain proper bookmarking. Once all 6 pin holes were drilled in the matched side cover, I ran the clamped covers up and down a stationary drill bit to clear the hole to a full 1/8”. We were now told to remove the Vice Grips that were clamping the master side cover to the matching side cover.

STEP11F – Cutout scribed master side cover - The master side cover was cut on the band saw up to be leaving the scribe line.

STEP11G - Scribe matching side cover to the master side cover - The master side cover is now used as a template to scribe the profile of the covers.

STEP11H – Cutout scribed matching side cover - The matching side cover was cut on the band saw up to be leaving the scribe line.

STEP11I – Connect master and matched side covers with pins - The master side cover and the match side cover were aligned using the “X” created in Step 11E to maintain proper bookmarking and 2 pins were inserted to connect the two covers.

STEP11J – Scribe, cut, and finish sand the ricasso end of both covers - The ricasso end of both covers was scribed to mark the end of the covers on the knife steel. The mark could be domed, cupped, straight, or flowing to accentuate the profile of the blade and/or covers. I chose to keep my vertical cover line straight to meet the spine of my knife at a 90° angle.

To conclude our day 4 class, the instructor told us that next week we’d be installing our covers with pins through the knife steel and start to shape the covers. Additionally, the finish grinding will commence and any fine bench work like jimping or file-work. We once again ended the class in fine fashion, cleaned up the shop and I left the campus without my piece steel but with a pinned set of covers that looked like they belong on a knife.

[Jeepergeo]

Great report. I'm looking forward to the report on Class 5.

[doglegg]

What a wonderfully interesting and informative post. Thanks again.

[bestgear]

Day 5
I unfortunately didn’t photograph my knife blade before I started grinding but two students were absent this week, so I used their knife blades to show a fully heat treated and tempered knife blade.

STEP 12 – Hardening the blade
Even though our instructor performed the hardening of our blades back in his studio between 4 and day 5, he reminded us about these important considerations that he took while performing the heat-treating and tempering of our blades:
• Precise temperature control is crucial throughout the process.
• Avoid tempering between 800°F and 1100°F, as it can reduce impact strength and corrosion resistance.
• Ensure the blade is clean and free of contaminants before heat treating.
• Always wear appropriate personal protective equipment and work in a well-ventilated area. Water in quenching oil can cause an explosion.
• Overheating during hardening can lead to excessive grain growth, which reduces toughness.

STEP 12A – Soak the blade for 20-minutes at 1950° in the heat-treating pouch
• Preheat: Preheat the blade in a furnace to 1250°F
• Equalize: Raise the temperature to 1450°F and allow the blade to equalize which lets stresses relax and the steel convert to harden
• Harden: Raise the temperature to 1950°F and hold for a 20-minute soak

STEP 12B – Tear open the pouch

STEP 12C - Quench in a 50/50 mix of Coal Iron Works #50 and hydraulic oil - Quenching is the process of taking our fully soaked blades and submerging them in a bath of quenching oil. The oil absorbs the heat from the metal, causing it to cool down quickly, allowing for the creation of our knives with increased durability. The slower cooling rate compared to water quenching allows for better control over the process, minimizing the risk of cracking and distortion, especially in complex shapes or parts with varying thicknesses like our knives. The controlled cooling can also result in a smoother surface finish compared to other quenching methods.

Our instructor’s choice of oil used for quenching offers cooling rates and properties specific to the 440C bar steel that was being treated.

STEP 12D – Normalize the blade by cooling it down to room temperature - Our normalized blades were hardened to 59-61C Rockwell.

STEP 13 – Tempering the blade - Tempering is a crucial heat treatment process for 440C stainless steel blades, as it reduces the brittleness resulting from hardening and improves toughness and ductility. Here's a general overview of the steps involved as told to the class even though they were performed by our instructor between day 4 and day 5:

STEP 13A - Soak the knife blades for 120 minutes at 350°

STEP 13B - Quench the knife blades in a 50/50 mix of Coal Iron Works #50 and hydraulic oil

STEP 13C - Normalize the knife blades by cooling them down to room temperature

STEP 13D - Wash the knife blades in an alcohol wash to remove any residual quenching oil

Steps 13A to 13D are repeated to a total of three cycles to ensure better dimensional stability and to convert any retained austenite into martensite, which further improves our knife blade properties.

STEP 14 – Flat Grind Blade
These flat grinds were done with no flat platen or jig and 100% by hand. I have quickly come to learn that grinding knife blades well requires practice, patience, and attention to detail. The key lessons that I have learned so far include:
• The importance of consistent angles and even pressure.
• Focusing on the plunge lines, using appropriate abrasives, and understanding the impact of grinding direction on the knife blade.
• Maintaining a consistent angle when grinding the flat surfaces of the knife blade is essential for achieving a symmetrical grind. It’s not as easy as one might think to apply even pressure across the flat of the blade and avoid uneven grinding and potential heat buildup.
• The higher grit belts are needed for finer finishing, while lower grits are suitable for stock removal. Using high-quality belts with good tracking is crucial for consistent results. I was quickly taught that the higher grit belts produce much more heat buildup on the knife blade than the lower grits which removed more stock.
• Knife grinding is a skill that requires practice. It's important to embrace imperfections and learn from mistakes.
• Excessive heat during grinding can damage the blade's temper. Using a coolant or taking breaks to allow the blade to cool down is important, especially when using high speeds or pressure.
• Use Dykem Layout Fluid to provide a contrasting background for grind lines, making them more visible. When Dykem is applied and dries, it can highlight these existing grind lines or surface imperfections.

STEP 14A – 60-grit grind, Dykem when complete

STEP 14B – 80-grit grind, Dykem when complete

STEP 14C – 120-grit grind, Dykem when complete

STEP 14D – 240-grit grind, Dykem when complete

STEP 14E – 400-grit grind, Dykem when complete

With 10 students in the class and only 2 grinders available for use it took most of the class to cycle through the five different grit belts that had to be changed for every student (5 grits x 10 students) = 50 belt changes or 25/grinder. The class worked together to make it happen in an orderly and efficient manner.

Our instructor wanted to inspect each of our pieces after each grind to make sure that as we went from a coarser grit to a finer grit that we were achieving the desired smoothness. This process is known as grit progression where you start with a coarse grit that allows you to quickly remove significant imperfections, old finishes, and shapes the knife blade. Our instructor taught us that:
• Progressing to finer grits helps to smooth out the scratches left by the previous, coarser grit, gradually refining the surface.
• Skipping grits can result in leaving deep scratches from the coarser grits that the finer grits can't effectively remove, leading to over-sanding, an uneven finish, and potentially blotchy or visible sanding marks.

In summary, to achieve smoothness and even finishes on our knife blades, it is essential to follow a proper grit progression, starting with a coarser grit and gradually moving to finer grits, and avoid skipping any grits.

STEP 15 - Scribe layout lines

STEP 15A – Horizontal Control Lines
Just as in Step 4B, 2 horizontal control lines were scribed for both the initial grind and subsequent grinds to build on the primary bevel. These layout lines need to be scribed now before starting the primary bevel grind so that enough steel is present to accurately mark the 60-grit grind line and the top horizontal grind line. The 60-grit grind line was scribed at 0.375” and the top horizontal grind line was scribed at 0.500” as depicted in the image below. These measurements were provided by our instructor.

STEP 15B – Vertical Control Lines
Just as in step 4C, a vertical control line is needed to establish a clean and crisp transition between the ground bevel and the flat portion of the knife blade. For my knife, I measured 0.250” (¼”) from the tip of my choil towards the tip of the blade and scribed that line 90° from the blade edge to the top horizontal grind line that was already laid out. This measurement was provided by our instructor.

[doglegg]

Love your detailed explanation Tom. Thank you.