The drill screams!
A customer brought in a 3T
ARX-TEAM stem for repair.
The successor model, the ARX-TEAM II stem,
uses a single M6 Torx titanium bolt on the steerer tube clamp side, but
Correction: It's actually M7, not M6—
thanks for the comment!
This older stem uses two M5 hex titanium bolts instead.
The upper bolt suddenly snapped clean off.
It broke almost flush with the back of the stem,
so there's no grip point to grab and turn it.
The customer asked if I could recover this
broken stub of titanium bolt.
Using a carbide drill with a worn tip from our shop,
I was able to grind away a small center punch divot.
The center point is slightly off,
but I can correct it from here.
This titanium is so hard that
regular steel drills won't even produce shavings—
it just smooths over like a dentist polishing a molar.
Most of the carbide drills we had in stock
were already dulled
(I threw them all out to avoid confusion),
so I asked the customer for a bit of time
while I ordered fresh ones.
A few days later (today)
With the new carbide drill, I made a half-hole deep enough
to engage the screw extraction tool.
I ordered multiple new carbide drill bits of the same size,
and when I swapped from the slightly-used new one
to a fresh one mid-job, the cutting action was noticeably different—
already the bit is getting a bit dull just from this one bolt.
I could have advanced the threads inward toward the stem interior,
but since the break face has no burrs,
I'm advancing the threads outward instead.
I was worried that the titanium might have seized up
the way titanium bolts sometimes do when they break,
but fortunately that wasn't an issue.
The thread-locking compound on the threads
didn't interfere with the screw extractor tool
(which I deliberately didn't photograph).
Without damaging the stem,
I successfully recovered the titanium bolt stub.
↑The recovered bolt stub
Doing this with a hand drill would be
some serious superhuman skill, I'd say...
I asked the customer why they thought our shop might be able to do it,
and they said they came after reading the article about
"The drill screams!"
So it seems like posting this kind of content here
creates a chain reaction.
A customer brought in a 3T
ARX-TEAM stem for repair.
The successor model, the ARX-TEAM II stem,
uses a single M6 Torx titanium bolt on the steerer tube clamp side, but
Correction: It's actually M7, not M6—
thanks for the comment!
This older stem uses two M5 hex titanium bolts instead.
The upper bolt suddenly snapped clean off.
It broke almost flush with the back of the stem,
so there's no grip point to grab and turn it.
The customer asked if I could recover this
broken stub of titanium bolt.
Using a carbide drill with a worn tip from our shop,
I was able to grind away a small center punch divot.
The center point is slightly off,
but I can correct it from here.
This titanium is so hard that
regular steel drills won't even produce shavings—
it just smooths over like a dentist polishing a molar.
Most of the carbide drills we had in stock
were already dulled
(I threw them all out to avoid confusion),
so I asked the customer for a bit of time
while I ordered fresh ones.
A few days later (today)
With the new carbide drill, I made a half-hole deep enough
to engage the screw extraction tool.
I ordered multiple new carbide drill bits of the same size,
and when I swapped from the slightly-used new one
to a fresh one mid-job, the cutting action was noticeably different—
already the bit is getting a bit dull just from this one bolt.
I could have advanced the threads inward toward the stem interior,
but since the break face has no burrs,
I'm advancing the threads outward instead.
I was worried that the titanium might have seized up
the way titanium bolts sometimes do when they break,
but fortunately that wasn't an issue.
The thread-locking compound on the threads
didn't interfere with the screw extractor tool
(which I deliberately didn't photograph).
Without damaging the stem,
I successfully recovered the titanium bolt stub.
↑The recovered bolt stub
Doing this with a hand drill would be
some serious superhuman skill, I'd say...
I asked the customer why they thought our shop might be able to do it,
and they said they came after reading the article about
"The drill screams!"
So it seems like posting this kind of content here
creates a chain reaction.