Knife #2

M

MammothSkullKnives

Active Member
This is my knife so far. Started as a 3/16x2x12 piece of 8670 flat stock. Cut a majority of it with an angle grinder, then spray painted the profile and removed the paper. Cleaned it up the rest of the way with the 1x30. I got the holes drilled out for the pins. Not sure if I got the wrong kind of drill bit, the blade was hardened a little from the grinding/cutting or if my drill gun isn’t strong enough but it was very difficult to make them. I got a drill jig to ensure a 90 degree hole but I’m wondering now if it was worth it. I plan to start on the bevel and handle this week. I’ll post a few more pictures of the what I have planned in the coming days. Also, wish me luck on freehand grinding my plunge lines! I’ve heard ignorance and confidence make good grinds.


https://imgur.com/a/7vjzwWH
 
CDHumiston said:
Looks like a good start!
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I’m waiting on my forge to get here as well, like you mentioned in my steel prices thread, I’ll heat treat my waste piece first to test my very noob procedure. But before that, how can I tell if my blade hardened a little during grinding? And if it did, do I have to do anything before HT?
 
Drilling is picky about speed and feed. Do it too fast and too light and insufficient pressure, the steel will work harden and the bit no longer cuts. Too much of that and you have to go to something like a carbide tipped masonry bit to bore through that hardened zone. They’re good to have around, and relatively cheap, especially for a bailout.

There are different angles on the bit end on regular drills available, too, but that’s for another time.
 
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MammothSkullKnives said:
I’m waiting on my forge to get here as well, like you mentioned in my steel prices thread, I’ll heat treat my waste piece first to test my very noob procedure. But before that, how can I tell if my blade hardened a little during grinding? And if it did, do I have to do anything before HT?
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Do the "file test". Try to cut the material with a file - if it grabs like soft steel... well - it's soft steel. If it doesn't grab, it's as hard or harder than a file. If it grabs just a little bit, it's a little softer than a file.

However, you don't have to worry about the steel hardening from grinding or whatever unless you're getting it VERY hot and then quenching it.

Buy good drill bits. These drill bits and the Bosch equivalent have worked really well for me.

A Harbor Freight 8" drill press would work well for drilling the pin holes in knives.

Adding to what Fitzo said about using carbide tipped masonry bits (which is a great trick and works well); generally masonry bits aren't really all that sharp. When you get the bit, you need to sharpen the edge. The safest way to do this is with a diamond file or a diamond sharpening stone. You can actually use a bench grinder, BUT you should not. Carbide grinding dust is very bad for your health - as in DO NOT BREATH CARBIDE DUST.

Anywho... sharpen up your carbide drill and take it slow. When the drill bit starts to come through the backside of the material, there's a good chance it's going to grab and the carbide edge is going to chip. If you can re-grind it, good. Otherwise throw it away. I consider them 1 time use.

As for what to do pre-heat treat... nothing. You can anneal the steel if it's hard and you want it soft so you can file or drill. Otherwise, don't worry about getting the metal too hot, too hard or whatever else before heat treat. As long as you aren't getting the metal so hot that it melts, you aught to be fine.
 
52 Ford said:
Do the "file test". Try to cut the material with a file - if it grabs like soft steel... well - it's soft steel. If it doesn't grab, it's as hard or harder than a file. If it grabs just a little bit, it's a little softer than a file.

However, you don't have to worry about the steel hardening from grinding or whatever unless you're getting it VERY hot and then quenching it.

Buy good drill bits. These drill bits and the Bosch equivalent have worked really well for me.

A Harbor Freight 8" drill press would work well for drilling the pin holes in knives.

Adding to what Fitzo said about using carbide tipped masonry bits (which is a great trick and works well); generally masonry bits aren't really all that sharp. When you get the bit, you need to sharpen the edge. The safest way to do this is with a diamond file or a diamond sharpening stone. You can actually use a bench grinder, BUT you should not. Carbide grinding dust is very bad for your health - as in DO NOT BREATH CARBIDE DUST.

Anywho... sharpen up your carbide drill and take it slow. When the drill bit starts to come through the backside of the material, there's a good chance it's going to grab and the carbide edge is going to chip. If you can re-grind it, good. Otherwise throw it away. I consider them 1 time use.

As for what to do pre-heat treat... nothing. You can anneal the steel if it's hard and you want it soft so you can file or drill. Otherwise, don't worry about getting the metal too hot, too hard or whatever else before heat treat. As long as you aren't getting the metal so hot that it melts, you aught to be fine.
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When put like that, it makes sense lol. I’m also in the market for a used drill press but their either too old or overpriced on market place. I’ll look into those drill bits you linked, thank you for the recommendations.
 
it’s real easy to work harden a drill hole. That’s a textbook sign that you’re not using enough pressure or you’re running the bit too fast, or the drill bit has gone dull.

This is where a propane torch comes in really handy. Heat that spot up to a red color and let it cool down. That will anneal the steel and make it soft again.
 
John Wilson said:
it’s real easy to work harden a drill hole. That’s a textbook sign that you’re not using enough pressure or you’re running the bit too fast, or the drill bit has gone dull.

This is where a propane torch comes in really handy. Heat that spot up to a red color and let it cool down. That will anneal the steel and make it soft again.
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I think I work hardened the hole by not using the right type of bit and not enough pressure. I am currently pricing out presses and am going that route. I’d even go for a used one in good condition. The tip with the torch is very good, I’ll definitely keep that in mind for the future.
 
I run my 1/4” and larger bits at 300 rpm. That’s about as fast as you turn a screwdriver by hand. Even though an electric hand drill will go that slow, it can’t make enough torque at that speed to keep going once the bit bites in, and if you’ve got one that does have enough power it will try to wrap you up in a knot around itself LOL. Many years ago I was up on a ladder with an absolute hoss of a drill making 1/2” holes. That thing grabbed and spun me and threw me off the ladder- which is a good thing because my arm made a complete circumnavigation around the drill motor before I could let go.
 
John Wilson said:
I run my 1/4” and larger bits at 300 rpm. That’s about as fast as you turn a screwdriver by hand. Even though an electric hand drill will go that slow, it can’t make enough torque at that speed to keep going once the bit bites in, and if you’ve got one that does have enough power it will try to wrap you up in a knot around itself LOL. Many years ago I was up on a ladder with an absolute hoss of a drill making 1/2” holes. That thing grabbed and spun me and threw me off the ladder- which is a good thing because my arm made a complete circumnavigation around the drill motor before I could let go.
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Haha bet that hurt. Hope I don’t send my knife flying across the garage with it.
 
fitzo said:
When using a drill press, you'll find it works best to clamp stuff when you drill. You'll understand the first time you helicopter a blade blank. Be careful: things get dangerous quickly.
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Take heed of this advice! I had ONE helicopter blade and thankfully it was not sharpened! Put a real nice bruise on my hand before I could hit the kill switch! After that I use my little drill press vise every time!
 
I tend to put a bolt in one of the table slots so it sticks up and I can brace the work against it. Quicker than using a vise - for me, anyway.

Otherwise I put vise grips on the work so they hit the column and keep the work from spinning.

Helicopter-o-death on the drill press is no fun.
 
MammothSkullKnives said:
When put like that, it makes sense lol. I’m also in the market for a used drill press but their either too old or overpriced on market place. I’ll look into those drill bits you linked, thank you for the recommendations.
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Don't be put off buying older equipment.

Honestly, a lot of the older equipment is really nice.

You can get a 10" drill press in good condition for around $100. There's a 10" Craftsman in good shape for $50 on Craigslist about an hour from me.

Heck, I'd take a drill press from the 1800s in a heartbeat.
 
Keep an eye out on craigslist not only in the tool-machinery section but under yard sales too.
this drill I actually found during my work day just driving down the road at a yard sale, he wanted $100, i offered $75 and and picked it up after my shift. with a $30 chuck from Amazon it runs and operates like new.
a lot of the older machines are better than the junk their putting out today except in high end machines.
Ka5eLE1.jpg
 
52 Ford said:
I tend to put a bolt in one of the table slots so it sticks up and I can brace the work against it. Quicker than using a vise - for me, anyway.

Otherwise I put vise grips on the work so they hit the column and keep the work from spinning.

Helicopter-o-death on the drill press is no fun.
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that is exactly what i do, too.
 
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