Making a titanium clutch centre nut for an R1

I made a titanium clutch centre nut for an R1 this morning, and thought i’d do a pictorial history of its making. Its 30mm A/F.

First i parted off about 11mm of 35mm diameter bar, the finished size is 1o.5 but i like a bit to face off to get it all square and a good finish. So put the piece in the chuck and square it up, i use the tail stock face to press it up against which gets it just about true.

measure the thickness
measure the thickness
face off to finished length
face off to finished length
centre drill ready for drilling thread hole
centre drill ready for drilling thread hole
Drill 18mm
Drill 18mm

 

The thread is 20x1mm, i like to drill undersize and then bore to size, its much more accurate.

Bore to size
Bore to size
watch your fingers when the swarf starts flying!
watch your fingers when the swarf starts flying!

This nut has an undercut on the back face

undercut the back face
undercut the back face
cut chamfer on edge of undercut
cut chamfer on edge of undercut
Deburr
Deburr

 

Whenever you make a cut on titanium you raise a sharp feather edge, this has to be filed off.

Cut lead in for thread
Cut lead in for thread
and deburr
and deburr

 

On larger threads like this i like to screwcut the thread almost to depth and finish it with a tap. Although this is only a 1mm pitch thread and would tap reasonably easily i still like to screwcut first just to give me and the tap an easier time

screwcut almost to depth
screwcut almost to depth
just about right
just about right
and finish with a tap
and finish with a tap

 

The back of the job will now have a sharp egde round the thread exit hole, so

turn round, square up and cut leadout for the thread
turn round, square up and cut leadout for the thread

 

Now its time to mill the flats, i like to finish them a couple of thou or so oversize. All spanners are a sloppy fit so i like to take some slop out, i like thing to fit as well as they can!

4 passes on each face
4 passes on each face
just nice
just nice
watch your fingers!
watch your fingers!
resharpen profiling tool
resharpen profiling tool
bevel corners front and back
bevel corners front and back
and deburr!
and deburr!

 

Then its a smooth off with emery paper and a quick polish on the buffing wheel and…..

BINGO!
BINGO!

 

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