Japanese-Style Marking Gauge Irons

I lied.  Or had a brain belch.  I said I would post next about the clamping system for the irons of my new double-iron marking gauge, but I am instead posting about the irons themselves before doing the clamping scheme on the next one.

After bending the twin irons to be nestled as perfectly as possible (you just knew that I would somehow merge Roubo and Japanese woodworking!) I began to fashion their cutting tips.

My first step was to saw both tips at the identical angle, a 90-degree point at 45-degrees from the axis.

I made sure to have the cutting bevel orientations in opposition to each other, with the outer iron bevel-in, and the inner iron bevel-out. 

Once the tips were cut and filed to have identical configuration and conformation I took advantage of the mild steel character of the metal to simply file the four bevels by hand, mostly with my treasured barrette files I got from Slav the last time our paths crossed.  I tuned the edges further by hand honing them with a small diamond stone and they were sharp and ready to get to work.

At some point I might try hardening the cutting tips as mentioned by reader Joe, but for now these are just fine.  The only “down side” is that I cannot lay out lines closer than 1/4″ apart.   Time will tell if this is a problem.

Next time – the iron clamping scheme.  I mean it.  Really.