Because in any real-world process, there is always uncertainty, and if you measure with enough precision you will always find variation in dimensions. Tolerances are specified so the machinist knows what is 'tolerable' and what is not acceptable. Assuming you are working in inches... A drawing dimension might be 1.50 +/- .03 . That would usually be a pretty easy tolerance to hit on a machined part. The machinist knows he doesn't need to be obsessive about this operation, and it will fit into where it is going as long as it is between 1.47 and 1.53 . He can measure it with a scale. Now, if it is 1.5000 +/.0001, it is much more difficult. The machinist needs to be very carefull here. He's going to need a good setup on good machinery, and something very precise to check the part with, in order to make a part that works. It is crucial that engineers and designers think about the tolerances they put on part drawings, because overly tight tolerances cost money, and overly loose tolerances might result in assemblies that don't work. Most of the time, the machinist does not know the context the part will be used in, so he/she shouldn't be left to make those decisions himself. When making parts on NC equipment right off CAD models, it is necessary to provide tolerance guidance to the machine shop to make sure the final part meets the need. Critical dimensions need to be identified at a minimum.
No. There are a few reasons why a pneumatic control valve can not be used with hydraulics applications. Firstly, pneumatic seals are incompatible to the chemical properties of hydraulic oils and they do not have the strength to accommodate the high pressures produced by a hydraulic system. Secondly, pneumatic valves are not designed for high pressure operation and the component would get damaged, burst or crack. Finally, the tolerances within pneumatic components would allow by-passing due to the slacker tolerances compared to hydraulic components. By-passing causes all sorts of problems by itself: Over-heating, leaking, internal structure damage of the component.
Engineering measurement tolerances are the permissible limits of variation in measurements. Example a piece of steel 25mm square where it would be allowed to be +.001mm or -.001mm on this size. The plus or minus is the tolerance
Pipe class is a collection of most compatible components considering dimensional and material properties for the intended service over a range on pressure and temperature specified.
limit, unilateral, and bilateral
It depends on the surface finish of the workpiece. For machined surface a magnetic base dial indicator is used. For rough or un-machined surfaces a surface gauge is used.
Dimensional tolerances are required for machined parts due to the virtual impossibility of being exact, down to the micron, on every dimension every single time.
The dimensions have to be within the tolerances of a specified datum.
Machined steel refers to steel that has undergone a machining process, where material is removed to shape or finish the steel part to the desired specifications. This method is used to achieve tight tolerances, smooth surfaces, and specific shapes in steel components.
With considerable effort. Engine blocks are cast using complicated molds, then machined to tolerance and required surface smoothness. Parts are mix of cast, milled and machined components. Then it's all assembled.
Artistic means components, elegant or specified.
Artistic means components, elegant or specified.
An optical comparator is a device that inspects manufactured and machined products to confirm they are within allowed tolerances. It does this, using optics, to project a silhouette of the article for inspection and the operator can physically measure any discrepancies that occur.
Machine drawing may be defined as the representation of a machine component or machine by lines according to certain set rules. A machine drawing generally gives all the external and internal details of the machine component from which it can be manufactured. The machining symbols, tolerances, bill of material, etc. are specified on the drawing. The-relative position of the different components and to make assembly drawing are also specified. IS: 696-1972 is the BIS Code for Machine Drawing.
By comparing the components to the specified standards.
I have found that new rotors are in need of turnig even though they are NEW. They tend to have not been machined with tight tolerances because they are mass produced. You may not feel anything in the break pedal but, if you do you have to take them off and do all that work AGAIN.
To eat poo
Machined - 2006 V is rated/received certificates of: USA:R