What sort of drill bit should i be using on a 5mm bit of bronze? It's hard stuff!
What sort of drill bit should i be using on a 5mm bit of bronze? It's hard stuff!
Standard jobber drill bit should do fine. Depending on the diameter of bit you're using, you might want to take more time to clear swarf (and possibly even use cutting fluid).
Thanks Peter and Nick
And drill slowly, by hand- you may think it's hard cos going too fast the bit tends to skate. Slow, it gets to cut in.
If it is a large hole you may want relieve the cutting edge on the drill with a small stone, this will help prevent grabbing and climbing of the work piece
How do you relieve the cutting edge, Bob?
That is a very good question, I will try to explain it I was taught how to do it 30 years ago by a toolmaker, you need to have a small oil stone such as a slip stone a fine Diamond lap would suffice, one of the Eze-Lap ones with the plastic handle
then apply a couple of light strokes to the back of the drill cutting edge, just to remove the really sharp edge, only slightly, not enough to round the edge
Thank you, I normally drill on a block of wood, which I was told would prevent it, but with harder metals and drills above 5mm, it sometimes takes me by surprise. Dennis.
Bronze, Brass and plastic are particular susceptible for some reason, I don't know the science behind it, something to do with being (for want a better word) " more sticky"
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