Metric Machine screws
- Thread starter BobbyB
- Start date
Hi, You have me there, I'll have to see if I can find a reference on one of the Spanish Pistol websites
Thank Bob
No but you need the pitch to track down the correct size.When you talk to a supplier they would ask what pitch.You will probably have to buy a box of 100 if located.A talented gunsmith would be your best bet as they make screws on many occasions.
R
You can sort out the pitch quite quickly, if you have a strong magnifier (10x or better loupe, preferably), and a digital caliper (which everyone 'should' have!).
Set the caliper to metric measurements, and using the magnifier to watch it, carefully measure the distance between the points or valleys of the other grip screw. Pick a place on one thread, and measure to the same place on the next thread, or several threads over, and divide by the number of threads, though that adds chances for error. If you do not have a screw, you can twist a little splint of wood into the hole and it will take the thread form, more or less, and you can measure off that.
To order a metric screw you pretty much need both the diameter and pitch. In inch sizes, the pitch is designated by the number of threads that are in an Inch, in Metric sizes, they go by the distance from one to the next as a direct measurement.
You are sure it's Metric?
Cheers
Trev
Set the caliper to metric measurements, and using the magnifier to watch it, carefully measure the distance between the points or valleys of the other grip screw. Pick a place on one thread, and measure to the same place on the next thread, or several threads over, and divide by the number of threads, though that adds chances for error. If you do not have a screw, you can twist a little splint of wood into the hole and it will take the thread form, more or less, and you can measure off that.
To order a metric screw you pretty much need both the diameter and pitch. In inch sizes, the pitch is designated by the number of threads that are in an Inch, in Metric sizes, they go by the distance from one to the next as a direct measurement.
You are sure it's Metric?
Cheers
Trev
fingers284
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A source for some "common size" very small metric or inch screws are hobby shops that cater to airplane, small car or train model builders. Take the off-side grip with the "nut" in it to use as a guide. You might not find an exact fit but even something with enough of a "tolerance" fit will be better than nothing.
Can't really assume anything, when it comes to gun screws. Machine tools were imported from all over, including from the US, in to many European countries, and on top of all the different standards they could have used, like the BA series mentioned above, IIRC, it could also be a total bastard in the truest sense, made to a spec that was decided in the factory, in order that no other screw but a factory or custom made one will work.
Winchester used a lot of screws with a pitch of 31 and 1/2 threads per inch, as one example. It was no big deal, as the factroy machines were set up and pounded out lots at a time, and the holes were threaded with tools made in the same plant. It kept the customer tied to them as a parts source, for one, and it prevented the use of more or less random hardware as a replacement, for the other purpose.
It is always possible that the pitch, the diameter, or both, were completely non-standard, or a mix of different standards (inch pitch on a metric diameter, or vise versa, as an eg.)
One can only be certain by measuring.
Cheers
Trev
