The pilot bit is attached to any common DTH hammer shank or top
hammer rod thread.
The casing shoe is welded to the casing. The pilot bit and ring bit
are locked together by the bayonet coupling. They drill a hole
large enough to allow the casing to be pulled into the hole. The
pilot bit and ring bit rotate with the drill string while the
casing shoe and casing do not rotate. When required depth is
reached, the pilot bit is unlocked by a slight reverse rotation of
the drill string. The drill string and pilot bit will be retrieved
through the casing, the ring bits and casing shoe will be left in
the hole for permanent casing system. Also the ring bits and casing
can be retrievable through the special design for ring bits and
casing shoe. We can manufacture both permanent Symmetric and
Retrievable Symmetric system which can meet your comprehensive
The below size of Symmetric systems which are available, and the
special design is upon customer’s requirement:
Symmetric 114, Symmetric 127, Symmetric 140, Symmetric 146,
Symmetric 178, Symmetric 195, Symmetric 219, Symmetric 243,
NEW DIAMOND Symmetric overburden casing drilling system
Symmetric is a system comprised of an ingeniously simple concentric
method of drilling through overburden with casing.
Symmetric can drill straight holes at any angle (including
horizontal) and to depths beyond 100 meters. Working together as
one efficient drill bit, the components are made up of:
A pilot bit with large internal flushing holes and external
Symmetrical ring bit (reamer) with internal bayonet coupling
Casing shoe for driving of casing.
Widely used in mines, quarries, earthworks and other engineering
drilling blasting hole, guardrail hole, mountain reinforcement,
anchorage and other engineering holes,geothermal exploration hole,
Well bore and other fields.
|Product model||Casing OD(mm)||Casing wall max (mm)||Ring bit OD(mm)|
Ring bit OD
|Pilot bte OD(mm)||hammer|
1. price commitment: in order to ensure the high reliability of
products, high-quality brand products are selected for raw material
selection. Under the same competitive conditions, no more products
will be provided to customers at a favorable price, based on the
reduction of the technical performance of products.
2. Quality commitment: product manufacturing and testing have
quality records and inspection data; the performance of the product
can withstand customer inspection.
3. Customer service: in order to create new diamond brand, enhance
the visibility of enterprises,establish corporate image, we serve
customers with the principle of "preferential prices, good service,
reliable product quality"principle.