how do you calculate the rpm needed to drill a 14mm diam hole in a piece of bronze?

Hi there, my son is doing his homework from a marine engineering course and I am totally out of my depth trying help him!! Does anyone know how to do this?

HELP please

Julie

2 Answers

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  • SGT. D
    Lv 6
    1 decade ago
    Favorite Answer

    Get yourself a copy of the "Machinerys Handbook" at the library and it will tell you all about calculating Metal cutting speeds and feeds.

  • 1 decade ago

    There are formulae for RPM and FEED RATES

    http://en.wikipedia.org/wiki/Cutting_speed

    you need to calculate the feed rate which is high speed slow feed related so you don't break the drill bit.

    Cutting speeds for various materials

    (Based on a plain High Speed Steel cutter)

    Material type meters per min feet per min

    Steel (tough) 15 - 18 50 - 60

    Mild steel 30-38 100-125

    Cast iron (medium) 18-24 60-80

    Bronzes 24-45 80-150

    Brass (soft) 45-60 150-200

    Aluminum 75-105 250-350

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