THIS is a holesaw

[jordhandson]

Just out of interest the teeth on these drills, what are they are made of?? Reason I ask is, the one i cut up for my knocker weight has teeth around the cutting edge , and I wondered if they are worth saving

 

[Pete.]

Just out of interest the teeth on these drills, what are they are made of?? Reason I ask is, the one i cut up for my knocker weight has teeth around the cutting edge , and I wondered if they are worth saving

Yes they are worth saving. Braze one onto a piece of flat bar and you have a great grinder wheel dressing tool.

The teeth are a sintered mixture of synthetic diamonds and various metallic compounds. Sintering means they are mixed in powder form then formed with heat and pressure to create a solid tooth. The composition depends on the application, softer compounds for harder concrete/materials and harder ones for cutting stuff like tarmac, brick and screed. The diamonds do the cutting whilst the binding cmpound determines the rate of wear. "softer" teeth give uo their diamondsmore readily and erode quicker to expose new (diamond) cutting edges whilst harder ones resist wear and under-cutting for more abrasive applications.

 

[jordhandson]

Now that what I like about this site, the information. Cheers Pete

 

[JOEPRO]

They have also came out with the "Head remover 5000"

 

[minimutly]

When we were building the turbine house at Llys y Fran dam we had a contractor in to core drill out the 750mm holes at the base of the concrete walls - 3 days work they said. Took them 3 weeks - the cantilever wall sections were tapered top to bottom, inch steel bars etc. They reconned the cores were over a tonne each..

 

[Dilkris]

From the first thread and video - the drill is electric but what is the second pipe going to the chuck? Is that water?