removal of busted thread-cutting tap

[dirtywhiteboy]

Trying to rethread the abs sensor bolt hole on the front right strut, the tap got bound up and snapped off level. Can't find a drill bit strong enough to cut through the metal of the tap, any ideas? Going to pick & pull tomorrow to get another strut assy unless you guys got better ideas. Thought about drilling and tapping a new hole next to it.

[jrobie79]

I was curious about this as well....

this is what wikipedia says about drill bits


Many different materials are used for or on drill bits, depending on the required application.

Steels

Soft low carbon steel bits are used only in wood, as they do not hold an edge well and require frequent sharpening. Working with hardwoods can noticeably shorten their lifespan. They are cheaper than longer-lived bits.

Bits made from high carbon steel are an improvement on low-carbon steel due to the hardening and tempering capabilities of the material. These bits can be used on wood or metal, but lose their temper, resulting in a soft cutting edge, if overheated.

High speed steel (HSS) is a form of tool steel; HSS bits are much more resistant to heat. They can be used to drill metal, hardwood, and most other materials at greater cutting speeds than carbon steel bits, and have largely replaced carbon steels in commercial applications.

Cobalt steel alloys are variations on high speed steel which contain more cobalt. Their main advantage is that they hold their hardness at much higher temperatures, so they are used to drill stainless steel and other hard materials. The main disadvantage of cobalt steels is that they are more brittle than standard HSS.

Hi-moly tool steel is heat treated at 1196 °C (2185 °F) and then nitro-carburize finished at 510 °C (950 °F) to be measurably harder than high-speed steel. Space age nitro-carburized steel withstands substantially higher drilling temperatures while maintaining sharpness.

Tungsten carbide and other carbides are extremely hard materials that can drill in virtually all materials while holding an edge longer than other bits. Due to their brittleness and high cost they are mainly used for drill bit tips, small pieces of hard material fixed or brazed onto the tip of a bit made of less hard metal. However, it is becoming common in job shops to use solid carbide bits, and in certain industries, most notably PCB manufacturing, it has been commonplace for some time.

Polycrystalline diamond (PCD) is among the hardest of all tool materials and is therefore extremely wear-resistant. It consists of a layer of diamond particles, typically about 0.5 mm (0.019") thick, bonded as a sintered mass to a tungsten carbide support. Bits are fabricated using this material by either brazing small segments to the tip of the tool to form the cutting edges, or by sintering PCD into a vein in the tungsten carbide "nib". The nib can later be brazed to a carbide shaft and ground to complex geometries that cause braze failure in the smaller "segments". PCD bits are typically used in the automotive, aerospace, and other industries to drill abrasive aluminum alloys, carbon fiber reinforced plastics and other abrasive materials, and in applications where machine downtime to replace or sharpen worn bits is exceptionally costly.

[Farbin Kaiber]

Try welding a nut to it.

[TobyB]

Burn it out with EDM... oh, right. Get a new strut. Seriously.

t

[FLG]

Try welding a nut to it.

Works every time..