Carbide drills generally do not cut but tear material. 3200RPM at 15 IPM because you have to figure at least a .003 radius on the lips.
Carbide over HSS a 30% increase in spindle speed and feed is acceptable.
1018 is Gummy so with a 1/4 in diameter drill I usually use the rule of one peck equals 1 times the diameter. If your depth is equal to or less than .75 deep (.25*3) drive straight through without pecking. For deeper holes reduce your peck by about 25% per 1 inch in depth.
Drill your first 10 holes and check the Margin for plastic deformation. If you have any plastic deformation reduce your RPM in 10% increments or as needed.
Chips should be a little long in 1018 steel so make sure you protect yourself and surrounding equipment with a guard.
Cheers and Happy cutting
Toby D.
"Imagination and Memory are but one thing, but for divers considerations have divers names"
Schwarzwald
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)
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