Do you believe 3/8ths of an inch will matter??????????????? I don't.

16" on center spacing has nothing to do with milled vs rough, but yes use a stud finder. 1950s home may have thicker plaster walls. You might find that proper anchors will also work.

I've found that the stud spacing is much more freestyle in old houses (at least in the old farm house that I used to live in).

They didn't have to make sure that the studs landed at the exact edge of the drywall (because they plastered) and they didn't have exactly sized fiberglass bat insulation to tuck in the cavity. So the spacing is more loosey-goosey.

The house I owned that was built in 1951, had the 16 inch apart spacing and studs were milled. Most 1950 houses I have seen have had milled, but, these houses were in Minnesota, so it may depend upon the part of the country you live in . Most people probably have no idea, until they tear something apart.

https://www.houzz.com/user/ky-cat Thanks for the info, I kinda figured they were milled because I'm finding out (with a magnet) that the studs are smaller than rough studs at 2". Mine seem to be more like 1.5".

https://www.houzz.com/user/ghijeff yes i know they aren't magnetic but i was just trying to find the center of stud by locating the (magnetic) screws in the center of them, which I found the center using a magnet. I am completely new to doing anything like this. Thank you for your reply!

You can't assume the screws/nails are in the center of the stud. You can just assume that they are somewhere in the stud.

And once you find the screw with the magnet, how are you determining how much of the stud is on either side of it?!?

We have a 1950 house with plaster walls. I find 16" o.c. is very approximate. I guess it didn't matter with plaster. Also, modern studfinders gauge the density of what they are scanning, which allows you to find the edge of a stud.

https://www.houzz.com/user/greg-2015 well I'm trying to see how much pull I have from the magnet to try to determine the length of the stud. Ikea shelves are just not the right length in inches for U.S. homes if you're trying to go into the wall stud. I will prob have to bolt them another way like using toggle bolts. Thank you for your reply!

well I'm trying to see how much pull I have from the magnet to try to determine the length of the stud

No offense, but that doesn't make any sense. A magnet only tells you where metal is. A stronger pull just means that you are closer to the metal. It tells you nothing about what the metal is attached to.

If you are an inch from the nail, it'll pull the same amount whether the nail is in a 1/4 inch sliver of wood or a 6 inch post.

greg,this is nothing more than another lonesome soul amusing themselves by seeing how many and how far they get people to follow down an imaginary path to nowhere. I feel sorry for them but playing their game just make's them keep doing it.

I disagree...everyone has to start somewhere...not all of us were born with a hammer in our hands.

OP, get a drill and the smallest drill bit you can find. Then drill a row of holes about a quarter inch apart. When you hit the stud, move the drill over and do a few more to find the end. It's tiresome, but it's the only way (for me, anyway) to be sure. And I agree about the Ikea shelves. Sometimes there's more than one hole to use (in the floating ones, I think) and anyway you really need to get at least ONE into a stud. I never rely on toggles alone.

FTR I have found stud finders to be less than reliable, but maybe I'm useless at using them or I buy ones that are poor quality.

I always try to find studs, but a 3/16 or 1/4 inche toggle will hold a awful lot of weight for sure. Toggles go where the studs aren't.

But,but,bu,,,,you must know if the studs have been planed or remain rough cut,,,,don'tcee see. As for being born with a hammer in hand,I wasn't born with a violin in my hand either,can you tell me how to play Wolfgang Amadeus Mozart's Eine Kleine Nachtmusik,?

Heck,I'd settle for some Charie Daniels licks if you will just tell me how.

Sorry, klem. I don't understand what you wrote..

klem1, it’s obvious that you’re reading everyone’s comments so you should realize that I’m new at this sort of thing so for you to say I‘m a lonely soul trying to see how far I can get people to follow me down an imaginary path to nowhere is a very ignorant comment and YOU’RE the lonely soul if you don‘t have anything better to do than to slam me. This was my first question I’ve ever asked online and you’re assuming I do this to get attention, boy you’re so ignorant!

I have found stud finders to be less than reliable

There are two types of stud finders. The 'simple' ones are just a magnet that twitches when it gets close to a nail. Those are pretty reliable, but you are finding the nails, not the stud.

The other type is electronic and I believe it detects the density of what it's placed on (or something like that). With those types, you usually choose the thickness of your drywall and then you can locate the exact edges of the studs. I've had great success with this type on drywall, but in my experience they don't work very well with plaster. Maybe the plaster/lath is too thick for the detector to differentiate between it and the stud? Or maybe I just didn't have a good enough stud finder.

The stud finder I use is a density based one, they're battery operated. It has an adjustment to set the depth for the indicator. A 1950's house will have better quality wood in the framing, don't be surprised when it's more difficult to drill than today's styrofoam studs.

Thank you for the above info! Off to check them out :)

(lol "styrofoam studs"....so true!)