Hi all, just a quick question
Why do watches have half head case screws or more particularly, why do they usually one full head and one half head. What is the point of half heads?
In my opinion half heads are just a pain in the neck.

Best regards
Francesco

Francesco,
I'm sure there are those here much more educated to answer this question, but my assessment is that on a half head screw you could turn it just enough to clear the case and let the movement out.
I've never had much success without removing the screw entirely anyway.

Francesco I agree with Dave and to me the half heads are worthless.

The half head screws are also the usual culprits that gouge out the marks on cases too.

Regards! Mark

I agree with Dave, Deacon and Mark. However I was told a tip by a friend that will fix Marks observation that I totally agree with.

Take a file or a grinding wheel and file away the leading edge on the underside of the half screw head so that it does not cut into the case.

Or replace the screw with a full head which is the method I prefer if I had enough full head case screws.

Harry

I agree I do not like them either and always heard just like others it was made for easy removal. My question was always this because I always heard it was the watchmaker who cut them so if a watchmaker was removing it to service it the screws would have to come out anyway so why so many seem to be cut.

Half-head case screws are anathema to me too, because they are not correct for the railroad grade watches I collect. To the best of my knowledge all Ball, Hamilton and Illinois railroad grade watches had full-head case screws as original equipment.

We All Hate Them !!!!

I agree with everybody on the fact that they are an absolute pain in the you know where, case destroyers I say. As for the notion about the serivcing jeweller doing the cutting I do not know, a few months back I was reading through one of my pocketwatch books and come across an advertisement about movements being available with half-head or full-head screws, if memory serves me correct the half-head screws were available on one of the cheaper movements. A soon as I can find the article I will let everyone know which book it was in.

A couple of years ago I brought up the same topic.I still hate them, and so did everyone else.They are without a doubt the all time stupidest invention in watchmaking!I think the factories actually made them that way, to save time taking the movement out of the case, which was a waste anyway because it only takes a few seconds to spin a full head screw all the way out anyway!Many times when turning in these wretched half-heads, you may need another few degrees of turn to get it tight, but it misses and clipped side now ends up against the case rim or below the edge.They used to make washers for these, but they look horrible and can make the screw head scratch a line in the case back on some screw-back cases.The best thing is to replace them with full heads, if you can find them.

Hi All,

It is very interesting to hear that most believe that half-head screws were altered by watch repairs after the movements left the factory. Why i question this is that if you have a look through some of the old reproduced catalogs from say Illinois watch co, Sears and Roebuck and Montgomery Ward (all of which were Illinois Watches) you will see many movements with half-head screws, I even noticed a 'Bunn' movement showing these. Hampden catalogs show half-head screws as well, including private label Hampdens such as Mermod, Jaccard & Co. I for one definately do not subscribe to the theory that only watch repairers were totally responsible, as these catalogs suggest differently.

I have to ask, where are these half head screws being offered in any company parts catalogs from the periods and years in the past ??

I have seen none. Yes I have seen drawings and perhaps photos of watches in brochures with these cut screws in company literature, but one has to wonder if that isn't just drawings or stock photos that were used in the industry "photo-shoots".

I believe the industry giants would have recognized that a cut, half head screw would have been severely weakened by cutting half of the head off. They were already aware that unless a movement is "snugged" down with the case screws, that continuous carry would loosen screws that weren't already tight and then the real problems would start with these screws backing out and catching on the inside of the case back damaging the case when taking it off and even requiring ruining some cases as the covers would have to be pried off.

These "bad idea" screws can be beveled or chamfered on their sharp ends so that they don't "dig" into the soft case material, but it still doesn't address the problem that if the half that holds is fixing to come to the 180 degree cut and it's not very snug, that going past there it is impossible to make another half revolution to where the screw will hold the movement in the case with it's uncut side.

I have to hold by the theory that no manufacturer would knowingly allow a new product to leave the factory with a defective part and a half head screw is definitely a defect.

There are some that will say even watches before the 20th Century had this feature from the factory and others will say that Waltham Premier Maximus came that way from the factory. I say "hogwash" !!

I agree it's a tough call, but it's a definite defective screw that is indeed now weakened and when someone can show these half head screws being sold in any company parts catalogs as a separate item, then I will become a believer.

regards,
bb

I agree with all above. In November I held and examined a Vacheron Constantine in an 18K case. The original case screws were still in it and I remember them because they were a "work of art". They were beautifully beveled and just looked classy. I think this is remarkable because I can't remember the case screws of most watches I look at briefly. It seems that some manufacturers went to great lengths to have appropriate screws everywhere else, so why not the case screws?