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Tony
12-14-2004, 05:47 PM
had to turn out a new gland nut (is that the technical term?) for a hydraulic piston today.

the inside of this big 'nut' holds 4 oil seals and an o-ring. had to make up a long boring bar with a square cut tip in order to cut the internal seats.

the internal grooves i had to cut were about 3/8" x 3/8" square in cross section.

i didnt want to do so much grinding to shape a 1" square HSS bar, so i brazed a small piece of 3/8" square HSS on the end of a bigger HSS square -- an L shape.
and ground a cutting edge on.

now, i was a bit nervous, as i've never had much luck plunging to cut grooves .. any wider than, say, 1/8", and i get alot of chatter. i wasn't looking forward to a 3/8" x 3/8" groove!

and i was afraid of what all the heat from brazing would do to the HSS. (it discolored badly, and i quenched it afterwards)

i dont know if it was the heat, or a one-in-a-million sharpening job on the grinder, but this thing cut like hotknife/butter. a steady feed had beatiful steel curls coming out of the bore. the seats were nice and clean.. no chatter!

did my brazing do something magic to the HSS?

-tony
(long-winded tonight)

laddy
12-14-2004, 05:51 PM
Hey,
Wake up,,,,Wake up,,,,You were dreaming! That will never work!!!!
Graet job, Fred

BillH
12-14-2004, 06:14 PM
HSS is king with me.

darryl
12-15-2004, 03:32 AM
Now you got me thinking. I could use a HSS tip silver-soldered to a boring bar for those tight places and custom applications. I would leave enough HSS to sharpen several times, then it could just be melted off and a new chunk soldered on.
I'm thinking to start with some 3/8 shaft, (fits my holder) mill a groove in the end with one edge of the groove at center height, then maybe turn a taper on the end, or just reduce the diameter a bit for the last half inch or so at that end. Then silver-solder the piece of HSS into the groove, with enough sticking out to grind to shape and sharpen several times. The cutting edge is the side of the HSS that is at center height, and will always be at center height if the groove is level. Some contouring on the HSS would create the rake and clearance angles, and whatever shape the cutting edge needed to be. Hmm.

Thrud
12-15-2004, 03:36 AM
tony

When you quenched it you hardened it to 60-66 rockwell C range (approximately) and of course it cut the metal well (why wouldn't it). Well done!

Guero
12-15-2004, 06:14 AM
I'm with Bill, HSS is king with me. While I have a couple of carbide 60* threading tools, they simply do not make as clean and beautiful thread as do the HSS which I've ground for that purpose. I do understand that carbide likes to cut fast and when I thread it is at slow speeds.... even so, I do delight in grinding a HSS blank for a particular job. I even enjoy sitting on a stool and honing the tool to a mirror finish. Yesterday I cut a 1/4 X 26 55* Whitworth thread for a clamp I'm making and used a tool which I had ground from a blank a couple of years ago. It cut like Tony says, like a hot knife through butter. The nut goes on like silk, no shake, no tight spots.

John Stevenson
12-15-2004, 06:32 AM
Darryl,
For the odd special job I get a piece of any old steel thats the right shape and size and blob a lump of Stellite onto the end with the TiG plant.
I used to use O/A but Tig is quicker and cleaner.
Then grind up and quench, does well for odd jobs and quick.

John S.