# Why is sine bar limited to 45 degrees?

## Why is sine bar limited to 45 degrees?

Explanation: The sine bars become impractical and inaccurate as the angle exceeds 45° because the bar is physically clumsy to hold in that position and even a slight error of the sine bar can cause large angular errors after this angle.

## What is sine bar formula?

The sine bar is based on trigonometry. The distance between the two setting rollers of the Sine Bar is given by L. From this we can write θ = sin^-1 (h / L). This is the formula for sine bar for calculating the angle or setting the workpiece to the required angle. This device is called “Sine Bar”.

What is the length of sine bar?

10-inch and 100-millimetre sine bars. In the U.S., 5-inch sine bars are the most common size.

What is the maximum angle sine bars can measure?

Sine bar is more accurate for angles between 15° to 45°, below and above to this limit, angles measured are not much more accurate. If a sine bar is to be accurate than the following properties must exist: (i) The distance between centres (L) must be precisely known.

### Why holes are made in sine bar?

The centre line of the rollers is parallel to the top face of the sine bar. There are holes drilled across the bar. This helps in reducing the weight, and also it facilitates clamping of sine bar on angle plate. The size of a sine bar is specified by its length.

### Why there are holes in sine bar?

Sine bar consists of a precisely machined corrosion resistant chrome steel. It is essentially hardened and stabilized. The relief holes are drilled into the body of sine bar to reduce the weight, and to facilitate handling.

Why do sine bars have holes?

What is a sine bar used for?

A sine bar is used in conjunction with slip gauge blocks for precise angular measurement. A sine bar is used either to measure an angle very accurately or face locate any work to a given angle offering a high degree of accuracy in measuring angles for milling, grinding and inspection applications.

## What are the chances of error in using sine bars?

Sources of error in sine bars 1) Error in distance between roller centers. 2) Error in slip gauge combination. 3) Error in checking of parallelism. 4) Error in parallelism of roller axes with each other.

## What is the accuracy of a sine bar?

A grade and B grade. A grade sine bar has an accuracy of 0.01mm /m length, B grade sine bar has an accuracy of 0.02mm /m length. The sine bar is based on trigonometry. The one roller is placed on a surface plate and the other is placed at height h by a slip gauge.

How do you calculate the height of a sine bar?

To calculate the gauge block’s height needed to set-up a sine bar to a specific angle all you have to do is take the SIN of the angle and multiply it by the sine bar length. The length of the sine bar is the distance between the centers of the sine bar gauge pins.

How is the sine bar based on trigonometry?

The sine bar is based on trigonometry. The one roller is placed on a surface plate and the other is placed at height h by a slip gauge. The distance between the two setting rollers of the Sine Bar is given by L. From this we can write θ = sin^-1 (h / L).

### What kind of measuring instrument is a sine bar?

Sine bar is a precision angle measuring instrument along with slip gauges. The name suggests that Sine bar work on sine principle. Slip gauge used to build up the height of sine bar.