Fisher Machine Shop
5" "Micro" Sine Bar, 2.5" "Micro" Sine Bar,
Indicator Holder with Accessories

5" Micro Sine Bar
2.5" Micro Sine Bar
Indicator Holder With Accessories
Ordering Information
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5" Micro Sine Bar

No. 50SB "Micro" Sine Bar

No. 50SB "Micro" Sine Bar $48.00
5" Sine Bar
Used with gage blocks these sine bars far exceed the accuracy that you would expect from this low priced precision product.

No. 50SB "Micro" Sine Bar Hardened and precision ground
5" Between centers of rolls.
Top parallel to bottom of rolls within .0002
Distance between centers of rolls within .0003
No. 50SB "Micro" Sine Bar setup on sine plate

Refer to Machinery's Handbook for use in finding precise angles using the sine bar and your gage blocks, adjustable parallels or planer gage.

(Gage block and massive granite surface plate not included.)

use of sine bar

The sine bar is the hypotenuse of a right triangle. The 2.5" gage block is the opposite leg of the triangle. If we remember the trigonometry we learned back in high school, sin theta = the opposite over the hypotenuse, or sin theta = 2.5/5 = .5
Using a calculator we figure the inverse sin of .5 and get a value of 30 degrees.

(remember, SOH CAH TOA, sin theta=opp/hyp, cos theta=adjacent/hyp, tan theta = opp/adj.)

Likewise we can figure the height of the needed gage block for a particular angle by finding the sin of the angle and multiplying by the hypotenuse. sin(30)*5 = .5*5 = 2.5"

If you look at the drawing you will notice that the rolls raise the triangle base by the roll radius, this does not matter as the triangle stays parallel to the surface plate.


2.5" Micro Sine Bar

No. 25SB "Micro" 2.5" Sine Bar

No. 25SB "Micro" 2.5" Sine Bar
$40.00

A nice short Sine Bar where space is an issue.

Tom Long generously took pictures of his use of the Fisher 2.5" Micro Sine Bar:

I have just made a few pics of the method I use (making use of the 2.5" sine bar I got from you) for setting the lathe compound to a precise angle. I'll send them to you in the next few days. FYI this isn't some "new" or "improved" way of doing it, it's just the way I do it. In this case I need to turn a short internal taper (.301" +/- .005 deep, major diameter to be .169" +/- .001) at 1.71 degrees per side, in a little stainless steel piece. 2.5*sin1.71 = .07460 My "zero" is a 1" gage block; the stack of blocks is .850+.124+.1006, giving me 1.0746. First I set it with a square against the carriage, then I make sure by using an indicator along the length of the sine bar. No change along the length means the angle is correct. If it needs adjustment I just bump it in gently until it's right on the money. Seems like a lot to do but it only takes about 5 minutes.
Using the indicator to verify the setting.

Indicator Holder With Accessories

IH11 Indicator Holder with Accessories $59.00

A Powerful Permanent Magnet Indicator Holder

Clamps Indicators with Dovetail, 5/32" or 1/4" Stems.

Universal Swivel Joint with Friction Movement

3-3/4" Overall Height

Used with the 1/4" Shank Accessory Adapter Can Be Chucked In Mill or Lathe Spindle

(Does Not Come With Indicator)

IH11 Indicator Holder with Accessories
Indicating in a Workpiece in the 4 Jaw Chuck Tramming on the Mill
Indicating in a Workpiece in the 4 Jaw Chuck
Tramming the Mill
More Versatile Great Range of Adjustment
More Versatile
Great Range of Adjustment

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Back to Nick Carter's Taig Lathe Pages.