How to tell U20 Nozzles from R16

[nismou20]

I have various SU parts around and couple I want to send in as cores but can’t tell differences between the two. I have no gauges but did notice few of these have orange color on them. Any help here?

[JT68]

You can use the needles as a gauge. The u20 needles are .100” at the large end of the taper, 1600 needles are .090”, so a u20 needle won’t fit in a 1600 nozzle.

[nismou20]

Damn JT, You got me there! Good one. Thanks.

[DAC21]

Also the nozzle is .092, so you can kill two birds with this pin gauge. I believe Keith Williams recommended using one and possibly it was Linda who tracked this down. Basically if you have slop in your nozzles when using the gauge time to replace them (1600 SU's) or use it to confirm what nozzle / needle combo you are dealing with.

pin gauge2.jpg

Available for $3

https://www.amazon.com/gp/product/B01BH ... =UTF8&th=1