Fast/Slow fuse?

I was looking for two kinds of fuses, one slow blow (10A, 250V) and one fast blow (4mA (?), 250V). Went to RadioShack and found that they had fast blow type fuse for 10A/250V and slow blow type for the other.
I just bought them anyway.
What would be the worst possible problem of using fast blow fuse instead of slow blow fuse, and vice versa?
If you need a slo-blow a fast blow will burn out when the device is turned on. A slo-blow will not protect a device that calls for a fast-blow. You should always use the type of fuse the device calls for.
Rwwear is right! Don't do it. You can get by with lower voltage fuses temporarily I believe but get the right ones. You can cook your gear.

Also, if the amp blew a fuse something bigger may be wrong any way.
I just wanted to check if the amps work, but I could not find right type of fuses.
I tested my amps with those types, and at least found out that the amps work!
I am not going to use those fuses any longer and will order correct types right away.
Any REAL electronics supply house, in your area, should have the correct fuses for your equipment. Check your yellow Pages under, 'Electronic Equipment & Supplies'.
I've been to two ACE hardware stores and one RadioShack, but they all don't have them. I guess they are not real electronic shop.
What I want is 10A 250V slow blow fuse and 4A 250V fast acting fuse. I will go for online.

I guess using a fast acting fuse instead of a slow blow fuse may burn the fuse faster, but may not affect other electronic components. Am I right?
I guess using a fast acting fuse instead of a slow blow fuse may burn the fuse faster, but may not affect other electronic components. Am I right?

If the fuse is for a power amp it may not hold when the amp is first turned on. The initial inrush current for the power transformer and charging of the caps in the power supply could be many times the FLA (full load amps) of the amp. A slow blow fuse has a built in lag time for the initial inrush of current.
JEA48 is correct about the inrush current. Some manufacturers insist on blasting the current in, and the risk of blowing fuses is far greater. A good 30-45 second bleed of power in the circuit is far easier on the system, and fuses, but few do that. When in doubt, go fast blow, and get a few. Check the manufacturer request as they know the inrush current risks to the fuse. Jallen
A quick on line search did not result in any.
Some suggest that lower amp fuse may work. For example, 8A 250V slow blow fuse may work well without affecting other components.
Any idea?
How about here: ( ( You have no actual electronics supply houses in your area? Yes- You can always go lower in amperage safely, but then the fuse may blow prematurely too.
Thanks for the link. But one is for fast acting, and the other is (slow blow) seramic type. I want a clear glass slow blow fuse.
Well, I will keep looking. I asked the 2 ACE store and Radio Shack about electronic supply store in our area, but they had no clue. I guess I will ask around to some electronic repair folks.
What I need is 6x30mm 10A 250V slow blow fuses. So far, I found clear glass 8A 250V slow blow fuses and ceramic 10A 250V slow blow fuses.
Are ceramic tubes replaceable with clear glass tubes?

In my experience as long as the rating is the same they are interchangeable, but I do not claim to be a fuse expert.
There's no difference in operation the of a fuse, between glass and ceramic. 10A 3AG(31.8mm X 6.4mm) fuses are made in glass, but they are not common. ie:(