Discussion and questions related to the course Motorsport Fabrication Fundamentals
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Could you please advise me where to find the drill speed chart, many thanks.
https://content.invisioncic.com/r226025/post-4193-0-41208400-1421081307_thumb.jpg
Hope this helps, it’s a great guide to drill speeds. Thanks
I can recommend this one. I have a copy and it helps out a lot. I should use it more to be honest..
Many thanks. However, after checking your video formula it does not correlate with the chart. Your video example shows 12mm drill in mild steel as 800rpm. The chart shows 420rpm. That’s a very large margin. Thanks anyway.
Good point, there are so many variables to drill speed. The problem it has a lot to do with feed. The faster the drill pushes through the material the more rpm you need, this means there really isn’t a drill chart that’s accurate.
As mentioned, there are a LOT of variables in acceptable drill speeds, and feed rates. The main ones being drill material - primarily strength and heat resistance, cutting tip design, flute design - primarily for waste removal, coolant - if any, and particularly for the larger diameters, the torque/power the machine can apply. Then, of course, there is the material being drilled.
I would expect the better twist drill manufacturers to have on-line charts you can download, or if you can find out the maximum cutting speed for the combination you are using, you can work it out from the diameter. If in doubt, slower and heavier feed is 'usually' the way to go.