Copiers are female, because once turned off; it takes a while to warm them up again. It's an effective reproductive device if the right buttons Are pushed, but can wreak havoc if the wrong buttons are pushed.
A tire is male, because it goes bald and it's often over-inflated.
A hot air balloon is male, because, to get it to go anywhere, you have to light a fire under it, and of course, there's the hot air part.
Sponges are female, because they're soft, squeezable and retain water.
A web page is female, because it's always getting hit on.
A subway is male, because it uses the same old lines to pick people up.
An hourglass is female, because over time, the weight shifts to the bottom.
A hammer is male, because it hasn't changed much over the last 5,000 years, but it's handy to have around.