Hi Im new here truth be told I only joined for help.

This tool doesnt fit the bottom bracket.....yet I have used it on several bottom brackets before with no issue...

Both are 20 teeth the BB is ofmega from the early 90s, the tool is generic ebay.

the bottom bracket says 36x24 if that helps anyone?

Try tapping it in with a hammer. It is hard to tell from the pic but that bottom bracket cup appears to be plastic. Those are always a tight fit on the tool.

Yes tap it in with a hammer I often had the same problem with those in the past, when they are screwed in too far the shell constricts the female spline. very common with plastic i also had an alloy one do the same.

Also some of these clone BB cup removal tools are not very good fits, it also maybe an optical allusion of the photos, but the splines on the BB cup do not seem the same as the tool.

It it's a "close but not quite" fit, then give the tool a couple of taps to get it seated like the other guys are saying. I'm only aware of one type of 20-spline bottom bracket tool, so I'm pretty confident you're using the right one.

As an aside... That's the first splined Ofmega bottom bracket I've seen or heard of. I think I found it on Velobase HERE, but there's no mention of what tool to use.

36x24 denotes an Italian-threaded bottom bracket -- 36 mm in diameter, 24 threads per inch. Be aware that unlike common English threading, both sides of an Italian bottom bracket are right-hand threaded. (Counter-clockwise to loosen.)

It was made out of alloy not plastic though it really does look plastic in the pics...bike tinker man nailed it...the tolerance using a cheap one was the fault. I live over 20 miles to my nearest bike shop but after reading bike tinkers answer I "felt" that was the issue...my LBS sold me a parktool after making sure it would fit.....thanks for the ideas folks its off and the right tool is now in my toolbox

Im glad you said that....could have been costly mistake when I bought a new one. Thankyou