Question about slip-joints

Although I visit this forum regularly this is my first posting. I am in the process of remodeling our bathroom and have just installed a new bathtub. It is an Americast Princeton tub and I have yet to hook up the drain assembly. The drain kit is from Watts and is of brass construction. My question is about slip joints. I've practiced assembling some of the drain and I notice that even after tightening (by hand) a slip joint I can still slide the two separate pieces up and down. Is this supposed to be the way these joints work? Once the drain is put in place below the bathtub and everything is closed back up will this movement cause me problems later on (separating, leaking, etc.)? Our drains are galvanized steel I believe and they transition into cast iron (house was built in 1953). I have tried searching this forum and elsewhere and I'm still unclear on this drain/slip joint issue. I don't know too much about plumbing, but I thought that a fitting once tightened should be "tight". Do I need to add teflon tape or putty or anything else at these slip joints?
I hope that I have described my problem so that someone can understand it.
Any help would be appreciated.
Patrick

I assume you have the slip joint washers in place.

Hand tight is not enough. These need to be wrench tightened snugly, and a joint should have no movement in it when tight.

Operative word is, "snuggly". They should not be reefed on with a huge pipe wrench until they won't turn any more. I like channel lock pliers, and I snug them up, then run water and watch carefully for drips. If any appear, then another 1/4 turn with the pliers.

"Slip-joint" means one pipe can slide in or out or up or down a little in relation to the other and even while being aligned elsewhere during assembly, then sealed and held securely in place when the nut compresses the tapered ring between the two parts ... and a key issue here is overall alignment. When installing a trap under a sink, I usually get all the pieces in place and lightly snugged, then "wiggle" everything just a little to relieve any binding or mis-alignment prior to tightening the connections. Also, it is helpful to hold the parts in place and watch for any undesirable movement while tightening the nuts. Whether or not it is possible to move any part after the connections have been tightened is not really an issue. Rather, be sure all the parts are free of burrs, dents and/or anything else (such as mis-alignment) that would/could keep the ring from ultimately making an absolute seal between the parts.

Thank you

Thanks for the replies. This helps to clarify things a bit. I'll let you all know how it works out when I install it
PatrickS