Type A is an old idea that is still used on gun holsters - the image should be self explanatory.
The thing is this one is best used on the spine of the blade so it really only works on either
a blade only sheath or semi-pouch sheath. The idea behind this style is the welt can be
pushed in against the spine and then locked in place as the sheath wears in.

Type B works good on any style sheath, but the welt needs to be wider than
normal - works well on an extra wide welt/double seam sheath. It should be
placed on the edge side just below the ricasso. The idea here is that by tightening
down on the chicago screw you can tighten or loosen the pressure on the blade
via compression.
On both types the Chicago screw heads must be turned down so that they are
smaller than normal for space sake. I just chuck them in my drill and file them
to size and then polish.

Now with all that said the best retention device is proper fit of the blade.
My method of doing this is to make the welt along the spine and the ricasso
(if there is one) 3/4 the thickness of the blade. HUNH! - well leather is compressible so....

Then - you may want to take a seat for this one - I skive the thickness of rest
of the welt, along the edge and the clip (if one) to about 3/32"! And yes you
read that right. In other words shape the welt to the shape of the blade.
But Chuck the blade will cut through the welt!
Well after at least 2000 or so sheaths done this way I have NEVER had one returned
for this reason (they are all tested thoroughly before leaving the shop).

So let's take a closer look - well the edge of a knife blade is no more than
around 5 microns max (unles REALLY DULL )and if the welt is GLUED IN PROPERLY
and is of the right width (about 3/8" normally) and the blade is fitted properly than
you should never ever cut through the welt. Anytime a blade cuts through a welt
for any reason to me it means that the sheath was either designed/built improperly
OR abuse was involved. Bold statement, but the caveat there is the blade must be
fitted properly and snugly.

When the blade is fitted properly it will not only be held securely in the sheath,
but will also draw smoothly. Note that I said that the welt must be glued in
properly - when a welt is glued in properly than the leather will tear before
the glue line will give way. It's the properly engineered sheath along with that
properly glued welt that really prevents the cutting of the welt/seam.

The thing is that sometimes a sheath may have to made in a trial and error
fashion to make it fit properly - but it is sometimes the ONLY way to do it right
and that my friends is the whole object - "good enuff" is just not good enough
in my book and should never be for anyone who really wants to do it "right".
(I do trial fitting by using small clamps and/or rubber cement to mount the back
to the face/welt - this sometimes takes an hour or more but the final product is worth it)

I am hesitant to post this due to that fact that I am pretty sure that there will be some
controversy but that is one of the things that makes the world go round.
Bottomline - the system works for me and all I can say is - try it - but if you
find a more comfortable or better way for yourself than DO IT!

An aside: No I DO NOT know everything - in fact practically everyday I learn
some thing new about my craft - but I have found methods that work better than others.
On the other hand NO method is so sacrosanct that I won't throw it out if something
better comes along, so......

Wild Rose Trading Co
Custom Leather Work
Chuck Burrows
PO Box 5174
Durango, CO 81301
www.wrtcleather.com
Email : Chuck