Join Date: May 2009
Location: Indiana/ Michigan line at the Lake
The #4 brass are usually more consistent at .026" (after lightly deburring) and
that's what I have mic'ed many of them at. Also, these were from the same
company bought in semi-bulk. (Used to get 'em at the foundry, and the maintenance
dudes dropped them often enough that I always hadda few laying around my toolbox.
I don't have a mic,but we did at work, and I check more than a few over the years.
Washers WILL vary from different suppliers. Unless it's a precision washer, the rolls
they are made from will vary in thickness as the tolerance variance is at least a few
thousanths over or under standard and still be in spec.
The SS take a harder punch to knock out the center and will deform a little
more during manufacture. Those should be tapped flat with a mallet or hammer
besides light sanding or rubbing them on a file on the punchout side (bottom).
If you have a micrometer use it. A caliper can be used too. Get the tips to touch,
then check it on a spark plug gauge.
Thank you for the heads up for those of us going with the X-needle. Good info.