Lathe Parting Tool From Old Circular Saw Blade

I'm just getting into doing some wood turning with my Shopsmith, and inherited a few random chisels from one of my mentors. Among the set was a really wide parting tool that is just not working for some of the items that I would like to make - most notably, some tree ornaments for the holidays.

I looked into buying one of the smaller parting chisels/knives, but the decent ones are more than I want to spend. I thought it would be just as easy (and much quicker) than waiting for a cheap one to ship - plus I absolutely love reusing items for different purposes than they were intended! Why buy something when you can make it just as well out of reused materials for far cheaper? I also find it rewarding as I'm learning a new skill to make some of the tools to support that endeavor.

I'll walk you through how to make a parting tool for wood turning using nothing but an old circular saw blade, some wood for the handle, and some round metal stock for the pins. My total cost on this project was about 50 cents, and this is really easy to do if you have some scraps and a basic set of hand and power tools!

Supplies:

• You'll need an old saw blade to make the knife part of the parting tool
• Some hardwood for the handle is necessary
• Some round metal stock about 3/16" or 5mm in diameter - I used a stainless steel roller off of an old printer that I'd disassembled in the spirit of reuse
• Sandpaper for both wood and metal
• Tung oil or boiled linseed oil for finishing
• Epoxy

Tools: (here's what I use, you can do this with far fewer tools than listed)

• Bench grinder
• Angle grinder with metal cutoff wheel
• File
• Drill bit the same size as your pins
• Hacksaw
• Belt or disc sander
• Hand saw or table saw
• Bandsaw
• Vice grips

First you will need to scare up an old circular saw blade - it is important to use this material rather than any old piece of scrap steel. Why, do you ask? Well, saw blades are made from high-speed steel (HSS), which is specifically meant to be used in tools for wood turning, cutting, etc. If you use a very soft, mild steel like from a bed frame it might bend easily or heat up too much. An old saw blade is easy to find, for sure - check garage sales.

It can't be too old as I hear older blades aren't made of HSS - often they are labeled as such, if the label hasn't worn off. Pick one with a thickness (kerf) that matches what you want for your parting tool - mine was pretty thin, like 1/16", which is perfect for what I wanted to accomplish.

I'm lucky to have a home supplies reuse center - Home Resource - that I frequent a lot. The blade and black walnut hardwood scrap came from there with a bunch of other stuff so I'm estimating my total cost at around 50 cents for these items. I tore apart an old printer years ago and the rollers had nice stainless steel rods in them so I kept those - it was perfect to use as the pins for this knife. Brass rod from the hardware store is not terribly expensive, I've used this for other knife handle pins before and it's a good substitute.

I don't have one of these tools and have never used one. So I googled images of what I might buy and came across this one - seemed easy enough to draw. I just drew two parallel lines about an inch apart with a straight edge and then eyeballed the shape of the front.

I clamped the blade securely to my bench - you are going to be using an angle grinder on a sharp object with pointy teeth, use safety glasses, gloves and ear protection and triple check it is clamped! Use good judgement here, please - if things are wobbling or not acting right, stop and assess before hurting yourself.

An angle grinder with cutoff wheel makes quick work of this. Whenever you are cutting metal that you intend to use as a tool like this, it helps to stop often to avoid heating up the metal too much - this can make the cutting edge not as hard for actual use. I just traced along the line with the cutoff wheel and got it in one go - if you mess up there is enough saw blade left to try again!

You have the rough cut out of your parting tool now, but it needs refinement. Nibbling away at it with a grinder works great - go slow and don't take off too much at a time. You can check if the edges are flat by placing against your workbench (if that is flat, a straightedge or file if not). If there is light in between the metal and the bench, it needs a bit more shaping. This part can just as easily be done with a file instead of a grinder.

It's time to put a finer edge on the parting tool, and clean up the face. I love the 3-packs of metal sandpaper at Ace, they come in 50, 80, and 120 grits and are useful for projects like this - and last a long time! I found a few pieces of glass at that home reuse store, they are perfectly sized to wrap the paper around. Clamp to the workbench and put something grippy underneath to have a good surface to work against.

I sanded all the edges smooth (you can file them down as well), then did the face. I tried not to remove all of the circular saw marks - it is great with hand-made tools like this to leave a bit of evidence of their provenance.

When you are done with this step you can harden and temper the blade if desired - given how little I will likely be using this tool and that it doesn't need to hold an edge like a regular blade, I chose not to - HSS steel is pretty hard as it is from my understanding, so I didn't think it necessary for this tool.

My piece of scrap was the perfect thickness for this project. I used one of my favorite 3d printed woodworking tools - this tracing guide - to mark the center of the scrap. I then traced out the knife part onto it, leaving about an inch past the end of the tang for the handle - you don't want to cut a slot all the way back if you want a longer handle enough to make it usable. I rounded the back of the blade tang, which you shouldn't do if you don't want a little gap where it fits in the slot - it doesn't impact performance, just leaves a bit of a gap.

I used my bandsaw to cut the slot for the blade, then cut around the shape of the handle. A coping saw could also work for this, it will just take a lot longer, especially with a hardwood.

EDIT: In the comments below, Instructables user ctubbs recommends a longer handle for better control. After using this tool I can see the benefits of this and would recommend adding an additional 2 to 3" to the handle, for a total length of around 6-7". One may need to add a third pin to compensate for the additional leverage exerted on the tang from this modification.

When making other knives or handles, I've found it helpful to drill out the holes for the pins or rivets before doing all of the sanding. Mark two (or three if your tang is long enough) spots to drill out the holes for the pins or rivets. I use a center punch to ensure the drill bit doesn't drift. Clamp in a vise on your drill press - this is very critical for safety reasons as well as accuracy. I like to drill one of the holes, then slide a bolt through it before drilling the other to prevent the tang from sliding out of place and the holes becoming misaligned. It's important to pick a drill bit that's basically the same size as your pins - if in doubt, go slightly under size. You want these to fit really tight without any gap, and can always widen the hole but not shrink it.

I used a disc sander for shaping with 60 grit paper, then touched up on my belt sander with 80 grit and finished with some hand sanding at 220 and 320 grit after inserting the pins in the next step. I always like to finish off hardwood handles like this with a bit of steel wool - it really polishes them up!

Now it's time to insert the pins or rivets. I measured the thickness of the handle with my calipers and transferred over to the stainless rod clamped in the vise. I added a little bit - about a millimeter or so - to grind down to a bit of chamfer on one end. This helps a lot when forcing through the wood and the hole in the metal. I cut it with a hacksaw, then ground down a bit on the bench grinder. To get it pretty exact in length, I placed behind the handle and sighted over it until I couldn't see the pin anymore. Since the handle I made is tapered, the pins are slightly different lengths so I measured with the calipers and did the same for the second instead of making an exact replica.

Add a bit of epoxy - you don't really need to much - to the tang before finally inserting to push the pins through.

To force the pins through the handle and tang, just hammer them through. I use pliers or vise grips to hold the pin straight for hammering in situations like this - it makes it much easier to get it in straight. Since my hole was just slightly smaller than the pin, I had to widen slightly using the side of the drill bit and ended up also using my deburring tool to get a really good fit.

My pins were just the right length so I did some slight sanding to make the wood meet them perfectly - if they are a bit long you can just sand them down flush without much difficulty. Buff with some steel wool, then tung oil or boiled linseed oil to protect and give your tool a nice shine! I also like to add Johnson's Paste Wax to metal tools to prevent rusting.

Making stuff is fun and making your own tools to make stuff out of random, reused items is almost equally as enjoyable in my opinion - I hope this inspires you to try something similar!