Hole Openers
Integral Body Sealed Bearing - S.H.I
Series
Tool Features
Designed for the enlargement of pilot holes,
directional drilling and large hole applications,
the Darron SHI series hole openers are
manufactured from Chromium Molybdenum Solid Alloy
Steel forgings, heat treated and conforming to
the requirements of AISI 4145 H Modified.
Cutter Features
Generally the cutter assembly consists of 4
machined parts : cutter, inner bearing race,
spindle and locking key – roller and ball
bearings and seals completing the assembly. All
machined parts are fully surface hardened.
Single Stage Hole Openers
Sealed Bearing – SH Series
Tool Features
The Darron Single Stage Hole Opener is a
simple but rugged design. The body is machined from
AISI 4145 fully heat treated alloy steel with arms
welded onto the body providing location for the
cutters. Arms and cutters are hardfaced for protection,
the cutters are available in 3 different designs for
varying conditions and rock formations (see Sheet 1a
for more details). The cutter assembly is a fully
sealed unit incorporating ball and roller bearings.
Retaining the whole assembly is achieved by a locking
pin. The design of the hole opener enables
quickoverhauls on the rig site. 3 or 6 replaceable
nozzles are used giving optimum mud circulation around
the cutters.
Cutter Features
Generally the cutter assembly consists of 4 machined
parts : cutter, inner bearing race, spindle and locking
key – roller and ball bearings and seals completing the
assembly. All machined parts are fully surface hardened
Large Hole Range Hole Openers
Sealed Bearing – LHS Type
Tool Features
The Darron Large Range of Hole Openers are
designed specifically for big hole applications such as
conductor holes and can open out from smaller than
normal pilot holes in a single pass. The opener is a
simple but rugged design. The body is manufactured from
AISI 4145 H Modified Alloy Steel, the saddles, ribs,
plates etc which complete the body assembly are welded
onto the body.
Saddles, ribs and other areas prone
to wear are hardfaced for protection.
Excellent circulation is achieved by the
strategic placement of nozzles between the cutters.
The cutter assembly is a fully sealed unit
comprising of large ball and roller bearing elements
that give optimum performance. The bearing race of the
cutter is rotationally held by a cam lock.
Cutter assemblies are easily changed on the rig
site usually readily available hand tools.
Cutter Features
Generally the cutter assembly consists of 4 machined
parts : cutter, inner bearing race, spindle and locking
key – roller and ball bearings and seals completing the
assembly. All machined parts are fully surface
hardened.