Several times lately I have wished I had a marking knife especially when working with dark wood where a pencil mark doesn't show up very well. The other day I thought

about buying a marking knife but after doing a little Googling I decided I could make one. I chose a 1/2" butterfly bit as the sacrificial lamb. I think it came out pretty good.

I wanted to be able to hang it up over my workbench so I added the paracord thing-a-ma-jig.

I like that!

Excellent Bubba. Making one has been on my round2it list for some time. Never thought about repurposing an old spade bit especially for a quick win. Thanks for the idea.

1 hour ago, Grandpadave52 said:

Excellent Bubba. Making one has been on my round2it list for some time. Never thought about repurposing an old spade bit especially for a quick win. Thanks for the idea.

@Grandpadave52 I can't take credit for the idea of using a spade bit (my dad always called them a butterfly bit) because the idea came from a Google search "DIY marking knife".

I'm a big fan of Paul Sellers and bought the same knife he uses. Love it!

On 1/30/2026 at 11:59 AM, Bubba said:

I think it came out pretty good.

That came out spectacular Bubba! Wonderful work and design, love this very much.

That's a term you don't hear much anymore. A butterfly drill bit is more often called a spade drill bit.

Nice work!

I keep trying all kinds of marking knives; I keep going back to the Sheepsfoot blade on a Stockman pattern pocket knife.

Nice job, I like double edged knives. Lets you mark right and left handed. A hundred years from now someone is going to find it and figure there must have been 3/4 and 1 inch models as well. Or they’ll think it was part of a set 1 of 2. Congratulations on keeping the mystery alive through the ages.