The angle is usuall 30 or 35 deg (looking down on the chain, relative to the bar). All sawchain I have sharpened want the file to be level, not tilted nose up or nose down. However, there is sawchain out there that wants the file to be tipped from horizontal. The sawchain will also determine the size of roundfile to use (assuming that is round ground and not square ground). Most consumers will use round ground sawchain.

In the end, it is the sawchain that determines how you will need to sharpen. If you can identify your sawchain, you can look up manufacturers recommendation on how to sharpen.

If you are unsure, now may be the time to get a new sawchain. It should come with a little pamphlet or instructions about how to care for the sawchain.

30 degrees is a good general rule of thumb, all the saws I've work with run a chain with a 30 degree cutter. Never heard of 35, 22 is common though.

Along with sharpen the teeth you will also want to clean out the oil feeder holes and bar slot that the chain rides in so the chain will get proper oiling. without oil it won't take long for it to get dull again and wear on the bar. Another problem is chain tension. Chain will loosen up quickly if ran dull or hot (from lack of oil or dull). Keeping the chain tight (as recommended my the saws manual) will keep the bar is good shape and reduce the chance of the chain jumping off the bar.

Both Oregon and Husqvarna show good sharpening technique.

Here is a link that might be useful: Sharpening video

What kind of chain saw is it and what model?

Many manuals are available free on the saw company's web site and if not, someone here probably has one and can provide the information.

Thank you to everyone who replied. I just read these and my husband is already in bed, but I'll let him know to see if any of this helps. Just in case someone out there does happen to have a manual. This is the info I have: It's a Poulan and the model number is UT10947, but when I type that model number into the Poulan website it brings up 'no results' so I may need to double check that model number (my son wrote it down for me). But if that just happens to be the right number and someone has a manual and can let us know for certain what the angle is, I'd appreciate it.

That sounds like a Homelite model number.