Close to, or close enough. Remeber we're talking rock-bottom simplest 555 circuits here, not precision 50:50 duty generators.I just thought maybe you were used the CMOS type, but do they really can reach to 50%/50% or just close to.
If it was 49:51 I'd say that was close enough to 50:50 for a hobby circuit with 4 components.
What is the actual duty you are getting? Can you post a 'scope photo?I used two TTL type, one is LM555, another one is NE555(TI), but they just approaching to 50%/50%, I'm not sure how much different for the high and low duty cycle, but I can see from the scale of O'scope, they are not equal.
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If the simple pin3 RC circuit is not exactly 50:50 you can bias it with a high value pullup or pulldown resistor to Vcc or gnd. If we could see your schematic and RC values (and the actual duty cycle) we could suggest a pullup or pulldown resistor (or trimpot) to tweak the duty cycle a few percent.