stupid chisel question

[Brad Wood]

Hi,

I've been looking at mortising chisels and I've got a question for you Neanders....

what is a registered mortise chisel Vs. a regular mortise chisel?

thanks guys

[Graham Hughes (CA)]

Registered means the sides are perfectly 90 degrees to the belly. A lot of mortising chisels, like the Ray Isles, have sides that are deliberately ground a couple degrees off a perfect right angle, for clearance. I'm not entirely sure why you would want it, honestly.

[Richard Niemiec]

I really haven't looked into Ray Isles distinction, but in my experience I see "registered" more in connection with sash mortise chisels, rather than in your robust pigsticker varieties. But then again I've lead a sheltered life.....

RN

[Brian Kent]

Registered means the sides are perfectly 90 degrees to the belly. A lot of mortising chisels, like the Ray Isles, have sides that are deliberately ground a couple degrees off a perfect right angle, for clearance. I'm not entirely sure why you would want it, honestly.

The slight clearance helps keep the chisel from getting wedged into the mortise after pounding it in.

[george wilson]

A registered chisel can make cutting mortises faster. You can make cuts with them,and force them over at an angle to "plane" the sides of the mortise free of stacks of chips. There was an article on doing it in FWW a few months ago. Not sure if I explained it so anyone can understand it.

I used to cut mortises by hand pretty quickly,not even drilling holes first. that was when I worked in public with 18th.C. tools. Now,I mill them out on my vertical mill,and just chisel the corners square. A milling machine (for metal) is a great wood working machine,too.

[Bruce Haugen]

George,
when milling mortises, do you use a router bit in the mill or a regular milling bit? I have access to a good Bridgeport at work that gets tempting at times, especially the idea of using the sliding table.

Bruce

[george wilson]

I just use 2 flute regular spiral milling cutters like you would use for aluminum. 2 flutes gives best chip clearance. I only cut about 1 diameter deep per pass so as not to clog the endmill with chips. That could possibly break the endmill,or score he insides of the mortise.

[Brad Wood]

thanks guys