Split point is self centering and reduces the need for end thrust.
Friction at workpiece is reduced.
118° point angles are ideal for use in materials such as mild steel and cast iron.
The 118° point creates easily controlled chips which are wide and thin.
Black Finish Twist Drills (also called blue finish) achieve their distinctive colour by steam tempering, a thermal process resulting in a porous tool coating.
This surface helps to keep lubricant on the tool, particularly important on the cutting edges, thus reducing friction and cold welding. The result is increased tool life.
Black finish tools are generally recommended for ferrous applications where the oxide layer aids chip flow and heat dissipation.
Sutton Tools Silver Bullet jobber drills are a general purpose drill bit designed for machine and hand held drilling in a wide range of ferrous & non-ferrous materials such as steel, aluminium, brass, wood & plastics.
Tungsten Carbide 4 Cutter Glass and Tile Drill Set
Precision diamond ground, double chamfered spear point tungsten carbide for fast cutting and extreme tool life (when used at slow to medium speeds).
Fast starting with reduced bit wander.
Suitable for use in: glazed and un-glazed ceramic tiles, glazed porcelain tiles, through-body porcelain tiles, plate (float) glass and annealed glass.
Not suitable for use with toughened or laminated safety glass.
Use a slow speed with steady but gentle pressure.
Reduce the pressure at break through.
For increased bit life use a cutting fluid/lubricant such as water or turpentine to reduce heat.
When drilling multiple holes in ceramic tiles, or when drilling vitrified porcelain, we recommend using either Bordo ceramic tile drills, the Bordo mist drill product range or Brilliant Diamond core drills.
Tungsten Carbide (commonly referred to as Carbide) is a chemical compound containing equal parts of tungsten and carbon atoms.
Carbide is three times stiffer than steel and is much denser than either steel or titanium.
Carbide has a very high abrasion resistance and can also withstand higher temperatures than standard HSS.
Carbide tools are often used for machining hard materials such as ceramics and stainless steel, as well as in situations where other tools would wear away, such as high volume production runs.
Because carbide tools maintain a sharp cutting edge better than other tools, they generally produce a better finish on parts, and their temperature resistance allows faster machining.
Whilst tungsten carbide is extremely hard it is also brittle so it is important to avoid bit “chattering” as this is the most common cause of tool failure.