DENTFIX Tungsten Carbide (STC) Spot Weld Drill Bit for UHSS, AHSS and Boron Steels. The Boron Killer. The ONLY way to drill through Boron Steel is with this bit. This drill bit was created to specifically cut spot welds from Boron Steel. Ultra High Strength (UHSS) also known as Boron Steel is used by many vehicle manufacturers to lighten the vehicles weight and increase gas mileage while increasing structural strength. Boron steel is about 3 times stronger than regular High Strength Steel. Thus you can form it half as thick yet increase crash worthiness. Volvo is an early adopter and heavy user. Typical locations are in structurally significant locations. Intrusion beams, inner core of the B-Pillar, bumper and cabin reinforcements are all likely places that contain this Ultra High Strength Steel. Made of Tungsten Carbide this 8.0 mm, special multi-layered coated, 3-fluted drill bit is the only bit that is tough enough to drill through and survive Ultra High Strength Steel, aka "Boron Steel". The three cutting edges help spread cutting forces over a greater area, thus helping prevent premature breakage. The Multi-Layer coating makes lubrication unnecessary. Think of it as a kind of Teflon anti-sticking surface. This bit may be used with our original red ringed 1800-rpm drill or better yet with our new blue ringed 1000-rpm drill. When used with the 1800 rpm drill it is suggested that air flow be restricted slightly to decrease rpm. We do not recommend this bit be used with off brand copies of our drill. The drill bit, being made of Carbide, is sensitive to incorrect pressures applied by these copies and thus subject to immediate breakage. Proper precautions must be taken to ensure the long life of this bit. DF-1690