{"id":2320,"date":"2016-01-11T08:44:24","date_gmt":"2016-01-11T16:44:24","guid":{"rendered":"http:\/\/pididu.com\/wordpress\/?p=2320"},"modified":"2017-10-16T14:10:43","modified_gmt":"2017-10-16T22:10:43","slug":"pcb-hole-size-for-awg-wire","status":"publish","type":"post","link":"http:\/\/pididu.com\/wordpress\/blog\/pcb-hole-size-for-awg-wire\/","title":{"rendered":"PCB Hole Size for AWG Wire"},"content":{"rendered":"

During design of a recent PC board, I did a quick search for “AWG diameter,” and was presented with a simple table listing the diameter of each gauge. When the boards came back, I found that the wires I had did not fit into the holes. That’s when I learned that wire diameter depends not only on the AWG size, but on the number of strands.<\/p>\n

\"PCB<\/a>
The blue wire on the left is AWG #20 stranded, while the yellow wire on the right is #20 solid. Only the yellow will fit into the 35 mil hole L11.<\/figcaption><\/figure>\n

It makes sense, now that I think about it. The most important characteristic of a wire electrically is how much current it can carry, not its total diameter. So an electrical engineer can specify, say, #20 wire, and be assured of a certain current carrying capacity. #20 solid wire is nominally 32 mils in diameter. I had therefore specified a 35 mil hole. What I found out later by searching “AWG diameter stranded” is that wire sold as #20 stranded can be 10\/30 (10 strands of #30, 35 mil total diameter), 19\/32 (37 mil), 26\/34 (36 mil), or even 41\/36 (36 mil).<\/p>\n

Fortunately for me, the wire was an inductor winding, and I should have been using solid wire anyway. When solid wire was used, everything fit perfectly.<\/p>\n

In summary, in the future, when I want a PCB hole to solder a wire into, I will take the total outer diameter of the wire I intend to use, and add 3 mils.<\/p>\n

Note to other novices like me: when specifying a FHS (finished hole size), you don’t need to worry about drill sizes or plating thickness unless you’re doing the boards yourself. When you go out to a contract board maker, Finished Hole Size means exactly that. If they say their holes are +-3 mils, then for a 32-mil wire, a 35-mil or larger hole should be fine.<\/p>\n","protected":false},"excerpt":{"rendered":"

During design of a recent PC board, I did a quick search for “AWG diameter,” and was presented with a simple table listing the diameter of each gauge. When the boards came back, I found that the wires I had did not fit into the holes. That’s when I learned that wire diameter depends not … Continue reading PCB Hole Size for AWG Wire<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[204],"tags":[],"_links":{"self":[{"href":"http:\/\/pididu.com\/wordpress\/wp-json\/wp\/v2\/posts\/2320"}],"collection":[{"href":"http:\/\/pididu.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/pididu.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/pididu.com\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/pididu.com\/wordpress\/wp-json\/wp\/v2\/comments?post=2320"}],"version-history":[{"count":0,"href":"http:\/\/pididu.com\/wordpress\/wp-json\/wp\/v2\/posts\/2320\/revisions"}],"wp:attachment":[{"href":"http:\/\/pididu.com\/wordpress\/wp-json\/wp\/v2\/media?parent=2320"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/pididu.com\/wordpress\/wp-json\/wp\/v2\/categories?post=2320"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/pididu.com\/wordpress\/wp-json\/wp\/v2\/tags?post=2320"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}