I'm not sure if this is just a United States thing, but why can't everything be consistent? I buy glass rods that are approx 5-7mm in diameter but 13 inches in length.
We give you the sizes of the beads like this....15x17mm but give you the hole size by telling you the mandrel is 5/64".
Widget Supply sent me a business card with my order. It's become dog-eared with use because on the back it has the inch and millimeter equivalent chart.
In making beads you will find these to be some of the common mandrel sizes.
1/16" 1.588mm
5/64" 1.9844mm
3/32" 2.381mm
1/8" 3.175mm
5/32" 3.969mm
3/16" 4.762mm
The mandrels are coated with a bead release which makes the hole size bigger, but how much bigger depends on how thick the coat of bead release is.
So to answer the question, I would say that if you are looking for beads with a hole size of 2.5mm you should look for beads made on 3/32" mandrel. Beads made one at a time by hand will always have variances from bead to bead, but that is the beauty of handmade lampwork beads...
oh thats a handy little chart...I'm going to have to save that. Great post!
ReplyDeleteWow, I didn't realize it was so complicated. Thanks for explaining in such detail!
ReplyDeleteA Happy New Year to you!
That's a very useful post Deronda, and you are so right about the measurements, why is it that they all have to be so confusing!
ReplyDeleteThat's really interesting - learn something new everyday!
ReplyDeleteThank you, and that did help. I think I have found the beads I need, and just need to purchase.
ReplyDelete