Sine Vises, Bars & Plates
Last updated on Thursday, March 21, 2019 12:22:15 PM Mountain US Time Zone

Angle CalculationsGage Blocks Sine Plate

Sine vises & bars allow quick & very accurate angle setting using precision spacer blocks.
The distance between the roll centers is quite accurate as are the other dimensions.
All of these sine vises & bars were hardened then precision ground to close tolerances.

 Required spacer size = Sine (Desired angle deg) x Distance between rolls Resultant Angle deg = Arcsine (Spacer size / Distance between rolls)

Notes: The calculator must be set to degrees not radians (rads).

MS Excel spreadsheets default to radians where 1 radian ≈ 57.2958 deg thus the
formula to calculate the sine of 30
deg would be: =sin(30/57.2958) which equals 0.5.
If the roll distance is in inches (or mm) then the spacer size is in inches (or mm).

For example, if you need to set a 30 deg angle & the distance between the rolls is 5.0000" (127mm), calculate the
sine of 30 deg, which is 0.5, then multiply by 5.0000" (127mm). The size of the spacer is exactly 2.5000" (63.5mm).
Sine bars are used in the same manner. For a given length sine bar & spacer block size
you can also calculate the resultant angle.
This calculation is the same as that for tapers.

Sine Vises 2-in & 3-in wide sine vise
s; both are 4" between rolls. Sine vise instruction manual. See more vises. Close-ups of the 2-inch sine vise. Sine vise with a precision spacer block. Underside showing the 4" center-to-center rolls.

Gage Blocks 81 piece, Grade B; +/- 0.000050" at 20 deg C (68 deg F), rectangular precision gage block set, from 0.050 to 4.0".
Example of a calibration reference table. See this Starrett document for info on wringing gage blocks. Low-cost spacer gage set
useful in setups. The gage block set has many more step sizes for the sine vise. 3" between rolls sine bar that is only a 1/4" thick.
Using the formula, the sine
bar angle is at 7.66225566 deg or 7 deg 39' 44.12" Assorted types & sizes (3" & 5" between the rolls) of sine bars. A 5" sine bar set at 10 deg. The 1" insert vise is wider than the bar thus it is clamped when the jaws are closed.
The insert vise jaw is smaller than its base allowing parts to be exchanged without disturbing the entire setup. 2-inch screwless vise on the sine bar.

Click on linked thumbnails

Sine Plate 1/4-20 flathead screws can be used to hold certain types of parts to the sine plate. 5" between rolls & hardened. One-inch vise adapter for the sine plate using MIC-6 aluminum.