ROCK TOOLS
Recommendations – getting the
most out of top hammer bits
Jeff Hogan, Boart Longyear Global Product
Manager, summarises how mining customers
can get the most out of top hammer button
bits. Training drillers and mining management
on bit care, maintenance and identifying
excessive wear can increase the return on
investment
Inspect bits frequently
Understanding the ground conditions and
regular inspections of a button bit are
necessary to prevent over drilling. To ensure
optimal performance and life, bits require
sharpening before the flat exceeds one third
of the button diameter. Working with a
technical representative is recommended to
establish specific guidelines since the
maximum suggested wear before reshaping
will depend on the button profile. Drilling in
non-abrasive ground can give rise to ‘snake
skin’ (small cracks) on the button surface. If it
is not removed by grinding, button fatigue
failure occurs.
Grind protruding inserts
Drilling in non-abrasive rock results in the bit
face wearing faster than the inserts. Excessive
insert protrusion, lacking sufficient steel
support, can easily mean breakage while
drilling and when retracting the bit from the
hole. To prevent this from occurring, grind the
buttons to restore the protrusion height.
launched My Drill Store, a new website
providing intuitive and convenient ordering of
drilling tools and parts online.
Robit digitalises drill steel
The new Sense Systems product family from
Robit the company says “drills deep into
efficiency and safety gains in rock drilling
through digitalisation.” The Sense Systems
product family is the result of an extensive R&D
program lending much of its insights from the
thorough understanding of rock and ground
drilling Robit has gained during its 30 years of
history and growth. The company states that
“the Robit brand itself has become a synonym
for high-quality drilling consumables all around
the world, and the digitalisation of drill steel
was a natural next step.”
In broad terms, Sense Systems seek to add
ever deeper levels of understanding and
optimisation to the drilling process through
digitalisation. A significant leap on this path was
taken when Robit became the first company in
the world to develop a patented system that can
measure hole deviation during the percussive
drilling process. The ‘S Sense’ for Top Hammer
surface drilling was launched at the beginning
of 2017 after an extensive testing phase. Along
with the S, a manual ‘M Sense’ is on offer, using
much of the same R&D knowledge and
technology that has gone into creating the
ground-breaking S.
MINCON IS
PEOPLE
PERFORMANCE
ENGINEERING
Button sharpening and reshaping
If button protrusion is adequate, satisfactory
re-sharpening can be achieved by use of a
preformed diamond faced tool (cups).
Sharpening is performed by holding the tool
firmly against the button and orbiting the
machine in a circle to achieve a uniform
surface finish. Diamond faced tools are
designed to cut carbide and not steel. It is
therefore recommended to have enough
protrusion of the button from the face to
avoid damage to the cup, bit or grinding
machine. It is important to implement
effective grinding tool management since the
tool profile gradually changes leading to
buttons that no longer match the desired
shape. Technical representatives can assist by
providing specific recommendations.
A ‘bit’ of training
It is always important to care for and maintain
tooling and equipment. Consider training for
drillers on getting the most life out of the top
hammer button bits. More often than not,
drillers come to work to do their very best and
everyone wants to improve. Provide them with
an opportunity to better their drilling habits
by sharing these tips.
NOVEMBER 2017 | International Mining 43