The strength and wear resistance of inserts are improve by using carbide inserts with high strength and high wear resistance.
Surface of the high precision bearing heat treated by using advanced heat treatment process to improve the load capacity and service life of the bearing.
The service life of the bearing is further extended by adopting harder and mort wear resistant material for thrust bearing.
Preventing reflux structure has dual function, it can avoid air counterflow and dust entering into bearing when the air-compressor stop working accidentally, and separate air and water in order to avoid water entering into bearing when it works normally to prolong the life of bearing.
Uses and applicable ranges of the bit
Uses: The bit is used for air drilling, e.g., for drilling operations in open coal mine, iron mine and non-ferrous mine. Applicable ranges: The bit is applicable for drilling hard and very hard formations with high compressive strength and high abrasiveness , such as magnetite quartzite, granite, hard sandstone, dolomite, chert and ironstone, etc.
Recommended drilling parameters
Weight on bit(WOB):35000-65000 Ibs
Rotary speed: 90-65RPM
Basic specifications of the bit
IADC code: 8-3-2
Type of the bearing: roller-ball-roller-thrust button
Cutting structure:
Top row and inner rows: ovoid compacts
Heel row: ovoid compacts
Shank: 65/8” REG(API)
Weigh: 59k
Recommended operating parameters of K series roller cone bits for mining：
Bit type
Normal WOB
KN/mm
(bit dia.)
Rotary
Speed
(rpm)
Cutting structure
Main features
Applicable formation
S412
0.70
120-60
The insert bit conical spherical compacts in inner row and in outer row
Soft with low compressive strength and high drillability, such as shale, soft limestone, soft sandstone, rudaceous clay, soft dolomite, salt bed and coal bed, etc.
S432
0.70-1.00
100-60
The insert bit, wedge compacts in inner row and in out row
Medium hard with high compressive strength, such as shale, soft limestone, dolomite with stringers and coal bed, etc.
S532
0.70-1.00
100-60
Wedge compacts in inner row, dull wedge or wedge compacts in outer row
Soft formation with low compressive strength, such as shale, soft limestone, dolomite with stringers and coal bed, etc.
S612
0.70-1.00
100-60
Conical spherical compacts in inner row, dull wedge compacts in outer row
Medium hard with high compressive strength and thick & hard stringers, such as hard shale, limestone, sandstone, dolomite and coal bed, etc.
S632
0.8-1.00
100-60
Conical spherical compacts in inner row, dull wedge compacts in outer row
Medium hard with high compressive strength and high abrasiveness, such as limestone, sandstone, dolomite and chert, etc.
S732
0.80-1.00
90-60
Conical spherical or bullet shape compacts in inner row, dull wedge compacts in outer row
Hard formation with high compressive strength and high abrasiveness, such as granite, limestone, sandy shale, dolomite and chert, etc.
S832
1.10-1,30
90-60
Bullet shape or ball-nose compacts in inner row, dull wedge compacts in outer row
Hard formation with high compressive strength and high abrasiveness, such as magnetic quartzite and granite, etc.
Note: The upper limits of WOB and RPM recommended in above table should not be used simultaneously.
