Find the dial reading to feed in along an angled compound slide so the full thread depth gets cut without doubling up on metal removal.
Compound infeed = thread depth / cos(compound angle). Feeding in along the angle instead of straight in lets one flank do most of the cutting, which keeps chip thickness and tool pressure manageable.
How it works
Setting the compound over to roughly half the thread included angle, commonly 29.5 degrees for a 60 degree thread, means the dial reading on the compound is longer than the straight radial depth. This calculator converts the radial depth you need into the compound dial number to actually feed.
FAQ
Why not just feed straight in radially? Straight infeed cuts both flanks at once which doubles the chip load and tends to chatter or tear the thread, especially in tougher materials.
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CNC Calculators · Thread Calculator · Tap Drill Size Calculator