According to B.B. u:
In article s.com,
(DoN. Nichols) wrote:

Hmm ... I would check to see whether a step drill (UniBit is one

Steps are nowhere near deep enough. The frame rails are at least 3/8
of an inch thick, and I got stuck with a doubled frame. I also haven't
seen a step bit that tops out at 5/8, but for what I suspect it costs I
could get my own reamer anyway.

O.K. I've got one which tops out at 7/8" IIRC, but that plate
thickness would be a killer.

[ ... ]

Different angle of cut (as was mentioned by another), and you
are running it at a much slower speed (manual power, instead of air or
electric drill).

No, it was also chucked in the drill. But I did make sure to run it
much more slowly.

Hmm ... I thought that the bridge reamers were designed to be
driven by a wrench, so they have a square shaft.

[ ... ]

Work hardening does not need much heat.

Do you happen to know the physics involved in work hardening? I've
never understood how it's even possible. I figure if I know how the
process works I can avoid it next time.

I *think* that it is simply a matter of crystals being oriented
by the pressure on the metal. Rub or roll on the metal (such as a drill
bit without enough force) and you get hardening.

[ ... ]

Not sure for the bridge reamer, but I would probably use
Molly-Dee (Molybdenum Disulfide in oil) with the step drill.

What's a product name I can search for? "Molly-dee" just got me some
stupid song's lyrics. Adding "oil" got me articles mentioning cutting
fluid, but nothing about where to get the stuff.

Molly-Dee *is* a brand name. It is made by Castrol, and I get
mine from MSC from time to time.

If you don't know about MSC, call 1-800-645-7270 and register
with them. They will send you a 4000+ page catalog every year which is
full of things which can help you. They will also send you several
sales flyers each month. (I just looked through the flyer which arrived
today, and Molly-Dee is not there, so your price would be a bit higher
than when a sales price is in effect.

Next time I do this I'll try rigging up some sort of leverage so that
I can mash down on the drill more efficiently. If I can get some access
to machine tools I can build a setup based on the auxiliary handle my
drill already comes with. I'm thinking a clamp-on collar with an air
cylinder and three chain hooks. Chain it to the frame, use a regulator
to set the pressure I want, and pull the trigger. But I'll probably get
get a pipe and wedge it against the handle. (:

Good luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---