Hard drills

February 10, 2020

Brendan from TTP Hard Drills sent me some of their cobalt drills and some cutting paste to review. He also threw in a handy drilling guide, a hat and some pens.

As I was looking around the Workshopshed for some hard materials to test, I was reminded of a couple of unfinished projects.

The first was a faceplate clamp project. This is a slotted aluminium faceplate with a cast iron angle plate. The project is roughly based on the Hemmingway Kits Quick Set Faceplate and was stalled whilst I worked out how to cut the slots in the faceplate using just the tools I had available. My thought here was that the cast iron would be a good test candidate for the TTP drillbits.

The second project was something I started back in 2008. The clamps to hold my drill vice to the drill table. The vice has been provided with slots which did not align with my table. So I had cut off the outer and made some T-Nuts and plates to hold it down. I had mostly finished these but was using one good and one bodged clamp, made from a bit of old gate as far as I can tell.

So I set about finishing off the other clamp. A simple drilling and tapping exercise. After marking out and centre punching the two holes, picked a 5mm drill bit to pilot the holes. Previously for drilling, I’ve used some general-purpose cutting fluid, applied via a small oil can. It’s easy to use but does splash about a bit so makes a bit of a mess.

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The cutting paste is a lot easier to use. You can just dip your drill bit into the can and get it nicely coated. The combination of the paste and the hard drill worked really well. A nice easy job to drill through 3mm mild steel and the bit hardly warmed up at all. A good sign as it shows that it is cutting not rubbing. As suspected, the split point of the drill meant that there was no wandering of the bit as it started.

I expanded one of the holes out to 9mm and the other to 7mm for tapping. This process went as smoothly as the pilot holes. I then used the cutting paste again to tap the holes.

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So now I’ve got a secure vice, I can move on to testing the drillbits with some harder metals.

By Andy from Workshopshed Add Comment

  Posted in: Drilling Tags: cobalt, cutting paste