K. Singer  4-Feb-00
Revised:  17-Nov-00
Revised:  8 & 14-Jan-01
Revised:  16-Jan-05

Many people, not necessarily familiar with watches, post questions on either the 
NAWCC or Pocket Horology, Chapter 174 Message Boards, trying to learn more about 
their watches, be they family heirlooms, or those just acquired.  In almost all instances, 
its necessary for those who try to help to know exactly what is marked on the watch 
movement (the "works").  The purpose of these notes is to provide instruction on how to 
open the various types of common watch cases.

Prior to the mid-1920's, only a small percentage of American-made watches were cased 
at the factory.  With only a few exceptions, the watch movements were made to industry 
standard sizes and cases were made to those same sizes.  Only a few of the companies 
that made the watch movements also made the cases, and when they did, they would 
frequently be sold separately.  A person would go to the jewelry store, select the make 
and grade (quality) of the movement they desired, and then pick out a case, or perhaps 
they would choose a certain quality of case and then use the balance of their budget on 
the movement.  The jeweler would then assemble the two in a matter of moments.  Even 
when watches were cased at the watch factory, the same model case might be fitted onto 
any variety of movements, or the same model/grade of movement would be put in a 
variety of cases.  Whichever set of circumstances occurred, the best documentation
available is for the movements, not the cases.  Thus it is through the movement that a 
watch's identification can be made.

WARNING:  If your watch case doesn't open with normal amounts of 
effort, don't force it!    Post a message on the NAWCC or Pocket 
Horology, Chapter 174 Message Board (see below), or contact one of 
the members who has answered watch questions, and describe your 
difficulty.  You should receive useful suggestions appropriate to your 
specific problem.

One of the most common types of cases is the Screw Back & Bezel (SB&B) case.  The 
back literally screws off.  In fact, so does the bezel, which is the ring around the dial that 
holds the crystal (glass).  SB&B cases are characterized by the fact that there are no 
hinges (there are "invisible-hinge" cases, but these are somewhat rare and have that other 
distinguishing feature of a hinged case, a raised lip by the winding stem).  On SB&B 
cases, you can see the fine lines of the joints between the back, the center ring (the part 
to which the winding stem is attached) and the bezel.  If there is only a one joint, that 
between the bezel and the center ring, the case is Swing-Ring case (see below) and the 
back won't screw off.  

To unscrew the back of an SB&B case, hold the watch dial down in the palm of 
your left hand, with the winding stem, more properly called the pendant, up against your 
left thumb.  Press the palm of your right hand down firmly on the back of the case and 
unscrew the back by turning it counter-clockwise (or, if its an English case, anti-
clockwise).  If its difficult to unscrew the back, check again to see that its not a Swing-
Ring, or invisible-hinge case.  If not, try using one of those circular pieces of sheet 
rubber, normally used in the kitchen to open tightly closed jars, between your right hand 
and the back of the watch.   A rubber-type coin purse also works very well for this.

Another common style of case is Hinge Back & Bezel (HB&B) case.  These have hinges 
for the back and the bezel, typically located down at the 6 o'clock position, but not 
necessarily.  As mentioned above, there should be a slightly raised lip on the back 
normally, but not always, near the winding stem.  There may also be a thin slot between 
the lip and the rest of the case.  I usually get my thumb-nail in the slot and slide it around 
the edge of the case, opening the back.  Resist the urge to pry the back open with your 
nail, you'll probably just break the nail.  Especially, AVOID USING A SHARP KNIFE 
GIVING YOU A BAD CUT.  Besides, if it slips, it'll probably scratch the case.  If you 
can't wait to ask somebody for advice and must use a tool, try a dull butter knife.  See: 
"Prying The Back Off," below.  However, if you can't find a raised lip, don't pry with a 
knife or any other tool - you probably have a different style of case.  If it's a HB&B case, 
it's possible that there's an inner back that can be opened the same way.

Hunting Case (HC) watches are those which have an outer, metal lid , or cover, over the 
crystal.  Otherwise, the backs open in a similar fashion to the HB&B cases discussed 

Opening The HC Cover
The cover is released by pressing down on the crown (the correct name for the winding 
knob).  When opening the cover of a HC watch, always hold the watch in your right 
hand, with the crown at your right thumb and with your left hand over the cover.  Once 
the cover is released, ease it open with your left hand, without letting it hit hard as it 
swings open.  There are no proper "stops" to catch the cover and letting it spring open 
eventually damages the hinge.  Similarly, when closing the cover, always press in the 
crown with your right thumb until the cover is firmly closed, then release the crown so 
that the inner catch, latches the lid in place.  "Snapping" the cover closed without 
pressing in the crown eventually wears away the lip that the inner catch grabs onto.

The term Swing-Ring (SR), or swing-out is usually applied to those cases in which the 
movement is mounted on a ring which, is hinged to "swing-out" from a cup-shaped back.  
An SR case appears similar to a SB&B case.  However, there are only two outer parts, 
the bezel and back, so there is only one joint visible when the SR case is carefully looked 
at.  To open an SR case, unscrew the bezel in a manner similar to removing the back of a 
SB&B case.  This exposes the inner ring, with its hinge at the 12 o'clock position and a 
groove at the 6 o'clock location.  

Next, hold the watch, dial up, in the palm of your left hand with the pendant facing 
toward you.  Grasp the crown with your right thumb and first finger and pull it out with 
moderate force.  You should feel the crown and stem move to an outer position, settling 
into that position with a soft "click."  To ensure that they're out of the way, set the 
hour and minute hands to 12 o'clock.  If the watch is pendant-set, you'll already have the 
crown pulled out to the correct position for setting the hands.  If the watch is lever-set, 
set the hands by using your thumb nail to pull the lever (which is located somewhere 
between the 6 and 12 minute marks) out, away from the center of the watch, parallel to 
the dial.  You can then put your first finger's nail into the groove at 6 o'clock and ease 
the ring and movement upward, out of the back.  BE VERY CAREFUL to make sure 
that you put your nail into the groove, or under the lip of the case ring.  NEVER PRY 
DIRECTLY ON THE DIAL!    It is sometimes helpful to slowly rotate the crown 
counter-clockwise while easing the ring up, but be careful to keep the second hand away 
from your finger.

The clamshell case is another form of the SR case.  Its bezel hinges open in a manner 
similar to the HB&B style case.  The pendant, with its crown and bow (the loop to 
which the watch chain or strap is affixed) is attached to the inner ring which holds the 
movement.  The inner ring is hinged to the back, normally at 9 o'clock, and if the ring is 
not too tight it can be opened by grasping the pendant and using it to lift the inner ring 
and movement, swinging it away from the back.  Normally, there is a notch or lip on the 
ring at 3 o'clock that you can put your nail under to help pry the ring out of the case if a 
normal amount of force on the pendant will not release the swing-ring.  BE CAREFUL 

Smaller pocket watches, and some inexpensive larger watches, are frequently mounted in 
cases whose back (and bezel) simply snap on (and off).  Display cases, also called 
salesmen's cases, are those with crystals on both sides of the watch.  They too are 
frequently snap back and bezel cases.  All but the cheapest larger snap back cases appear 
the same as HB&B cases in that they'll have a small lip and can be opened in the same 
manner as a HB&B case.  Smaller snap back cases, usually those having art deco designs 
wherein the case is not circular, will have a groove into which a fingernail can be inserted 
with which to snap the back open with.  If this doesn't work and you feel that you must 
pry the back off, see: "Prying The Back Off," below.  If a lip or notch is not present, 
the case is probably not a snap back case and no attempt should be made to pry off the 
case back.  Before putting one of these cases together again, carefully examine the 
mating surfaces, especially at any "corners."  Usually there is a small locating pin, and 
corresponding hole, to assist in determining the correct rotational position for the back 

For HB&B, HC and Snap Back Cases, if you have tried putting a fingernail in the back 
lip/slot and running it around the edge of the case and it didn't work, and you can't wait 
to ask somebody knowledgeable for help, you may wish to pry it off.  There are tools 
specifically made to be case openers.  If a case opener isn't available, I  prefer something 
dull, like a butter knife for safety's sake (which what the case opener tools resemble), but 
I know many people have successfully used a sharp knife for years without a problem.  
In either instance, BE CAREFUL!  If you have any doubts, wait to ask somebody.

Set the watch face down on a soft mouse pad and use a low stool so that you can look 
closely at what you're doing without bending over too much.  If you're right-handed, 
hold the knife, in your right hand, with the sharp edge in the slot.  Then, use your left 
thumb against the back edge of the knife to hold the knife in the slot.  Using moderate 
force only, rotate the knife handle a little in each direction to "pop" the back off.  This is 
a wrist action - don't actually move your elbow - keep the knife parallel to the table top 
and to watch.

If this doesn't work, it may be time to visit a jewelry shop where watch repairs are done 
on the premises and ask them to show you how to open it. Most reputable places won't 
mind, and you may wish discuss the costs of have the watch serviced there.

WARNING:  If your watch case doesn't open with normal amounts of 
effort, don't force it!    Post a message on the NAWCC or Pocket 
Horology, Chapter 174 Message Board, or contact one of the members 
who has answered watch questions, and describe your difficulty.  You 
should receive useful suggestions appropriate to your specific problem.

	National Assoc. of Watch & Clock Collectors (NAWCC):
	NAWCC Chapter 24, Atlanta:
	NAWCC Chapter 174, Pocket Horology:


Bezel	        The ring that holds the crystal.
Bow	        The loop to which a watch strap or chain is affixed.
(Case) Back     The portion of the case covering the back.
Crown	        The knob used to wind the watch and set the hands.
Crystal	        The glass (or clear plastic) that protects the dial and hands.
Dial	        The "face" of the watch.
HB&B	        Hinged Back & Bezel.
HC	        Hunting Case
Movement        The watch's "works."
NAWCC	        National Association of Watch and Clock Collectors.
Pendant	        The portion of the watch which holds the winding stem and crown.
SB&B	        Screw Back & Bezel
Snap Back       A case whose back "snaps" or "pops" off.
SR	        Swing Ring.
(Winding) Stem	The shaft that winds the watch and sets the hands.