Sine bar calculator. Stack height for any angle.
Pick your bar, type the angle, and get the gauge block stack. Or enter a stack and get the angle back in decimal degrees and degrees, minutes, seconds.
Result
- Bar length
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- Angle (decimal)
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- Angle (D°M'S")
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- Stack height
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The bar is the hypotenuse.
Put gauge blocks under one roll. The bar length is the hypotenuse, the stack is the opposite side, and the angle follows from the sine.
H = L × sin(θ)
θ = asin(H / L)
L is the distance between the roll centers, not the overall length of the bar. Common bars are 5 in, 10 in, 100 mm and 200 mm.
Above about 45°, small errors in the stack turn into larger angle errors. For steep angles, set up the complement and turn the part, or use a sine plate made for it.
Good to know
What length do I enter for my sine bar?
The center-to-center distance between the two rolls. It's usually stamped on the bar. A 5 in sine bar is 5.000 in between roll centers, even though the bar itself is longer.
Can I type minutes and seconds?
Yes. 30°15'20", 30 15 20 and 30d15m20s all work, and so does decimal degrees like 30.2556.
How many decimals should I build the stack to?
Gauge blocks go to 0.0001 in or 0.001 mm, so that's what the result shows. On a 5 in bar, 0.0001 in of stack is about 4 arc seconds at small angles.
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