PB Cohen Creations

This post isn't actually about rivets; rather, it's about matching your wire, measured in the B&S or American gauge, to the corresponding drill bit number. You need a tight fit (but not too tight), or it will be difficult (or impossible) to make the rivet.

It's the end of the semester at the Ann Arbor Art Center, so I've been seeing a lot more students during "open studio" hours trying to finish up projects, and a few people have been wanting to work on rivets. Their materials kits include, among other things, 20 gauge wire, and a #67 drill bit. Which, as far as I'm concerned, is wrong. I did a bit of research, and this is what I found:

B&S (American)	Oppi Untracht (1)	Tim McCreight (2)	Rio Grande (3)	class supplies (4)	my memory (5)
14	51.7	51	52
16	55.3	54	55
18	59.5	56	60		60
20	67	65	68	67	66
22	71.5	70	72

Notes:
1. Metal Techniques for Craftsmen, Doubleday, 1968/1975
2. Various books published 1982-1997
3. Tool Catalog, 2011
4. Recommendation of instructor and Armstrong Tools
5. 'Nuff said

I consider Untracht, McCreight and Rio Grande to be excellent sources, and Armstrong Tool & Supply Company is right up there, as well. And yet, these sources don't agree on anything.

Untracht gives a clue in his table, which includes measurements for inches, millimeters, B&S Gauge, and Stubbs Steel Wire. The only B&S wire gauge with an exact drill bit size is 20, at #67. 18 gauge, according to Untracht, is halfway between a #59 and #60; 22 gauge is halfway between a #71 and #72. 14 gauge is closer to #52 than #51 (that is, in increments of hundredths of an inch, —

No. Wait. I can't really see any coherent method to how he is listing any of these five items. No regular increments of inches or millimeters, which you think would make it easy. This suggests that he was simply trying to match up B&S, Stubbs and drill bits to whatever measurements corresponded to these three, different, industry "standards." Suffice it to say that 18 and 22 gauges are "halfway" between drill bit numbers on his table (thus my ".5" notations); 14 gauge is closer to 52 than 51 (thus my "51.7" notation), and 16 gauge is closer to 55 than 56 (my "55.3" notation). Go look at Untracht's table "Comparison of Measurements" (on page 457 in the 1975 edition of "Metal Techniques For Craftsmen") and see what you can make of it.

I should really make a bunch of holes with my drill bits and match them up to actual wire — as much as that might help, considering how various manufacturers might have minor variations in their finished products. I might just do it one day, though. I am that anal retentive. (But I am also lazy.)

Anecdotal evidence, however, suggests that I am right. I took a student's drill bit #67 and was unable to fit a 20 gauge wire in the hole. I enlarged that hole ever-so-slightly with my drill bit #66, and it fit. HA HA!

Well, I won't claim vindication until I do a more thorough experiment. But still, the differences in "knowledge" are surprising, particularly the range given for 18 gauge: 56-60?!? That's a pretty wide range, in the scheme of tiny little measurements.

What gauges/drill bits do you use for rivets?