Internal diameter or ID grinding might appear uncomplicated. After all, instead of grinding the outside diameter, one simply focuses the process on the inside diameter. However, it’s not quite so simple and there are several important things which must be taken into consideration, if you want to do a quality job. Let’s take a look at some important factors to consider for getting the best results.
Set Up
ID set up is quite different from outside diameter machining. It is very important to check the contact area where the wheel meets the work piece. However, other factors must be noted like the speed of the wheel, how fast the piece is fed through the grinder and the kind of spindle used in the process. All these things will affect the quality of your work.
Not the Same as OD Grinding
If your shop does a great deal of outside diameter machining, you may be tempted to go with identical wheel specs when you perform inside diameter work, but this could lead to several problems. You might experience vibration or chatter issues and even burning. However, this can be avoided when using the right wheel for the job.
How Hard is the Material?
Hard material has special needs when it comes to ID grinding. It will cause abrasive grains to dull quickly. Instead, wheels made of friable (softer and easier to crumble) material will work best and provide maximum results. If you are machining high speed or carbon steel, you should consider aluminum oxide abrasive wheels.
On the other hand, for softer materials (cast iron, aluminum or bronze) diamond abrasives may be best. Of course, silicon carbide may be a less expensive alternative.
Stock Removal
If you need to remove a great deal of material at one time, you should choose a coarse grain wheel. Yet, when you are working with a hard alloy, a fine grain wheel is best because you have more cutting edges working for you.
Wheel Size
Did you know the size of the grinding wheel is a big factor? If you use a wheel which is oversized, it may not produce enough pressure and this can dull its cutting ability quickly. Plus, you have less coolant flow which can slow down the process. On the other hand, undersized wheels are prone to excessive wear and this contributes to your maintenance costs.
Is ID Grinding Right for You?
Not every shop is suited for all kinds of internal dimension grinding. If you are having problems, consider hiring an experienced machine shop for this work. This is one less thing you’ll need to worry about.