Extension Steel Rods
With the longer steel tending to be larger in diameter. Conventional extension steel is characterized by a duplicate thread on each end of the steel. Hexagonal and round cross sections are available. Round cross sections are more prevalent.
Standard Length of Extension Steels
1200mm 1800mm 2400mm 3100mm 3700mm 6100mm
Male/Female (M/F) steel
An alternative to couplings is to include the female part of the threaded connection as an integral part of the drill steel.
Like most developments, it has its advantages and disadvantages. Male/Female drill steel pro- vides more rigid connections and is easier to uncouple and handle. The service life also tends to be better than with separate couplings. This is fortunate because the coupling end cannot be re-placed.
The advantages of drilling with M/F steel include: easy handling, quicker uncoupling, tighter con-nections and the potential to drill straighter holes.
Tunneling steel
It is common practice to bump up the drive end of drifting steel for added strength at the rockdrill end to accommodate larger diameter and shank adapters. Drill steel is available in many standard lengths to match the drill feeds on a multitude of available drifting jumbos. Please contact your Boart Longyear Sales Representative for further information.
Since the coupling does not enter the hole, a bit diameter closer to the steel diameter can be used. This enhances flushing and hole accuracy.
Various Different Size and Different Quality Requirement
A. Flexible Supplying Plan to make your purchasing much more fun than before.
B. Never Ever fast response to every customer saving your precious time for ever.
C. Special Order proceed in advance without down payment give you 100% confidence and trust care.
D. We accept customer tailer-made order based on samples or drawings.
