GAUGE AND TYPES OF GAUGES-FITTER ONLINE NOTE
TYPES OF GAUGE
1- Limit gauge
2- Ring gauge
3- Snap gauge
4- Plug gauge
5- Filler gauge
6- Screw gauge
7- Screw pitch gauge
8- Radius gauge and Fillet gauge
9- Wire gauge
10- Fishtail gauge
11- Taper ring gauge.
12- Adjustable caliper gauge.
13- Progressive plug gauge.
1- Limit gauge:-
i)- Components manufactured using mass production method are checked only to ensure that the sizes are with in the precribed limits.
ii)- The most economical method of checking such components is by using limit gauges.
iii)- These gauge are used in inspection because the provide a quick means of checking.
2- Ring gauge:-
i)- These are used to check the outside diameter of the work pieces.
ii)- Separate gauge are used for checking GO and NO-GO size.
iii)- The NO-GO gauge is identified bu an annular grooves, cut on the knurled surface.
3- Snap gauge:-
i)- Snap gauge are used as a quick means for checking sizes within certain limits by comparing the size of the parts with the opening of the gauge.
4- Plug gauge:-
i)- Components manufactured using mass production method are checked only to ensure that the sizes are with in the prescribed limits.
ii)- The most economical method of checking such components is by using limits gauges.
iii)- These gauge are used in inspection because they provide a quicky means of checking.
iv)- These gauge have two ends namely GO and NO-GO.
v)- The go end of the gauge must go in to the feature of the components and the NO-GO end must not go in to the same feature.
vi)- The GO is made longer then the NO-GO end for easy identification.
5- Filler gauge:-
i)- These are thin steel blades hardened and ground to various size.
ii)- They consist of a number of small lengths of steel of different thickness with measurements marked on each piece.
iii)- Used for checking the clearance between two mating parts.
iv)- Vanes are from 0.03 to 1mm thickness.
6- Screw gauge:-
ii)- The thread profile on each blade is cut for about 25 mm to 30 mm .
ii)- The pitch of the blade is stamped on each blade .
iii)- The standard and range of pitches are marked on the case .
iv)- For obtaining accurate checking while using the screw pitch gauge , the full length of the blade should be placed on the threads
7- Screw pitch gauge
i- A Screw pitch gauge A screw pitch gauge is used to determine the pitch of a thread.
ii- It is also used to compare the profile of threads.
Constructional features of gauge
1- Pitch gauges are available with a number of blades assembled as a set.
2- Each blade is meant for checking a particular standard thread pitch.
3- The blades are made of thin spring steel sheets, and are hardened.
4- Some screw pitch gauge sets will have blades provided for checking British standard thread (BSW, BSF etc.) at one end and the metric standard at the other end
8- Radius and fillet gauges
1- Components are machined to have curved formation on the edges or at the junction of two steps. They are called radius and fillets.
2- The size of the radius and fillet is normally provided on a drawing.
3- The gauges used to check the radius formed on the edges of diameters are fillet gauges.
4- The gauges used to check the fillets are called radius gauges.
5- They are made of hardened sheet metal each to a precise radius.
6- They are used to check the radii by comparing the radius on a part with the radius of the gauge.
7- Figure shows the application of a fillet gauge to check the radius formed externally.
8- Figure shows the application of a radius gauge to check the fillet formed on a turned components.
The other typical applications are
9- Checking the corner radius of a part being filed to shape.
10- The radius and fillet gauges are available in sets of several blades which fold into a holder when not in use.
11- Some sets have provision to check the radius and fillet on each blade.
12- And some sets have separate sets of blades to check the radius and fillet.
13- Each blade can be swung out of the holder separately, and has its size engraved on it.
14- Fillet gauges are available in sets to check the radii and fillets from.
1 to 7 mm in steps of 0.5 mm
7.5 to 15 mm in steps of 0.5 mm
15.5 to 25 mm in steps 0.5 mm
15- Individual gauges are also available.
16- They usually have internal and external radii on each gauge and are made in sizes from 1 to 100 mm in steps of 1 mm.
17- Before using the radius gauge
i- Check that it is clean and undamaged.
ii- Remove burrs from the workpiece.
iii- Select the leaf of the gauge from the set corresponding.
iv- To the radius to be checked.
18- Figure shows that the radius of the fillet and that of the external radius are smaller than the gauge.
19- Try a smaller gauge to determine the radius dimension.
20- File or machine the work piece if it has to be of the radius of the gauge.
21- The radius of the fillet and that of the external radius are larger than the gauge.
22- Try a larger gauge if you need to find the radius dimension.
23- If the work piece has to be of the radius of the gauge you may have to reject the work piece.
9- Wire gauge:-
i)- The standard wire tool to measure the predefined wire diameter.
ii)- It consist of oblong plate having holes of different size to receive different size wires. Each hole is stamped with a number which define the holes and wire size.
iii)- This stamped number starts from 1 to 80. O This wire gauge also available in circular shape.
10- Fishtail gauge:-
11- Taper ring gauge:-
i)- These gauges are used to check both the accuracy and the outside diameter of a taper.
ii)- Ring gauge often have a scribed line or step ground on the small end to indicate the GO and NO-GO dimension .
12- Adjustable caliper gauge:-
i)- These gauge are generally 'C' shaped and are adjustable to the maximum and minimum limits of the part being checked.
ii)- When in used the work should side into the GO anvil but not in to NO-GO anvil.
iii)- Snap gauge and adjustable caliper gauges can be used for checking external sizes in any place along the length of a work.
13- Progressive plug gauge:-
i)- These plug gauge are used for checking the diameter of a straight hole.
ii)- The GO gauge check the lower limit of the hole and the NO-GO gauge checks the upper limit.
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