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Halloween lamp
I've made this lamp for Halloween 2020 out of old circular saw blades that we took out of service when the got blunt or damaged. The holes in the centre of the blades were too small to make this design work so they had to be enlarged. These saw blades are made of hardened steel so they can't be cut by normal tools and a grinder would be too imprecise. I did consider heating them to soften them and then cutting into them but that would cause them to discolour and warp. I decided to try out hard-turning on the metal lathe, this is a technique for cutting fully hardened steel using inserts made of cubic boron nitride(CBN) which are very expensive. Despite it's age our lathe proved easily up the job and by holding the blades against the face plate and using a CBN insert I was able to open out the centre holes large enough to make this work.

In order to support the blades, 3 holes were drilled into each blade using a solid tungsten carbide drill and then they were threaded onto 6mm rods, separated by stainless steel spacers to give the proper effect. It was then put onto a base and fitted with a 300mm tubular LED bulb.

This lamp is the twin of the bandsaw blade lamp